From 83324e01267337803fe0faf9f5103b42c036dbba Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Sat, 8 Mar 2025 10:57:52 +0100
Subject: [PATCH 01/13] repl: add support for multiline history

---
 benchmark/repl/parse-history-from-file.js     |  97 +++++++++
 lib/internal/repl/history-utils.js            |  77 ++++++++
 lib/internal/repl/history.js                  |  24 ++-
 lib/repl.js                                   |   9 +
 test/parallel/test-repl-history-navigation.js |  63 ++++--
 test/parallel/test-repl-history-utils.js      | 187 ++++++++++++++++++
 6 files changed, 443 insertions(+), 14 deletions(-)
 create mode 100644 benchmark/repl/parse-history-from-file.js
 create mode 100644 lib/internal/repl/history-utils.js
 create mode 100644 test/parallel/test-repl-history-utils.js

diff --git a/benchmark/repl/parse-history-from-file.js b/benchmark/repl/parse-history-from-file.js
new file mode 100644
index 00000000000000..999451e7cbf512
--- /dev/null
+++ b/benchmark/repl/parse-history-from-file.js
@@ -0,0 +1,97 @@
+'use strict';
+
+const common = require('../common.js');
+
+const bench = common.createBenchmark(main, {
+  n: [1e1, 1e2],
+  size: [1e3, 1e4],
+}, {
+  flags: ['--expose-internals'],
+});
+
+const bechText = `
+a ={
+a: 1,
+b: 2,
+}
+
+\`const a ={
+  a: 1,
+  b: 2,
+  c: 3,
+  d: [1, 2, 3],
+}\`
+
+\`const b = [
+  1,
+  2,
+  3,
+  4,
+]\`
+
+const d = [
+  {
+    a: 1,
+    b: 2,
+  },
+  {
+    a: 3,
+    b: 4,
+  }
+]
+
+var e = [
+  {
+    a: 1,
+    b: 2,
+  },
+  {
+    a: 3,
+    b: 4,
+    c: [
+      {
+        a: 1,
+        b: 2,
+      },
+      {
+        a: 3,
+        b: 4,
+      }
+    ]
+  }
+]
+
+a = \`
+I am a multiline string
+I can be as long as I want\`
+
+
+b = \`
+111111111111
+222222222222\`
+
+
+c = \`
+111111=11111
+222222222222\`
+
+function sum(a, b) {
+    return a + b
+}
+
+console.log(
+  'something'
+)
+`;
+
+async function main({ n, size }) {
+  const { parseHistoryFromFile } = require('internal/repl/history-utils');
+
+  bench.start();
+
+  for (let i = 0; i < n; i++) {
+    parseHistoryFromFile(bechText.repeat(size));
+  }
+
+  bench.end(n);
+}
diff --git a/lib/internal/repl/history-utils.js b/lib/internal/repl/history-utils.js
new file mode 100644
index 00000000000000..c52988dad42105
--- /dev/null
+++ b/lib/internal/repl/history-utils.js
@@ -0,0 +1,77 @@
+'use strict';
+
+const {
+  Array,
+  ArrayPrototypeJoin,
+  ArrayPrototypeReverse,
+  StringPrototypeCharCodeAt,
+  StringPrototypeTrimEnd,
+} = primordials;
+const os = require('os');
+
+const kBrackets = { '{': 1, '[': 1, '(': 1, '}': -1, ']': -1, ')': -1 };
+
+function parseHistoryFromFile(historyText, historySize) {
+  const lines = historyText.trimEnd().split(os.EOL);
+  let linesLength = lines.length;
+  if (linesLength > historySize) linesLength = historySize;
+
+  const commands = new Array(linesLength);
+  let commandsIndex = 0;
+  const currentCommand = new Array(linesLength);
+  let currentCommandIndex = 0;
+  let bracketCount = 0;
+  let inString = false;
+  let stringDelimiter = '';
+
+  for (let lineIdx = linesLength - 1; lineIdx >= 0; lineIdx--) {
+    const line = lines[lineIdx];
+    currentCommand[currentCommandIndex++] = line;
+
+    let isConcatenation = false;
+    let isArrowFunction = false;
+    let lastChar = '';
+
+    for (let charIdx = 0, len = line.length; charIdx < len; charIdx++) {
+      const char = line[charIdx];
+
+      if ((char === "'" || char === '"' || char === '`') &&
+          (charIdx === 0 || StringPrototypeCharCodeAt(line, charIdx - 1) !== 92)) { // 92 is '\\'
+        if (!inString) {
+          inString = true;
+          stringDelimiter = char;
+        } else if (char === stringDelimiter) {
+          inString = false;
+        }
+      }
+
+      if (!inString) {
+        const bracketValue = kBrackets[char];
+        if (bracketValue) bracketCount += bracketValue;
+      }
+
+      lastChar = char;
+    }
+
+    if (!inString) {
+      const trimmedLine = StringPrototypeTrimEnd(line);
+      isConcatenation = lastChar === '+';
+      isArrowFunction = lastChar === '>' && trimmedLine[trimmedLine.length - 2] === '=';
+    }
+
+    if (!inString && bracketCount <= 0 && !isConcatenation && !isArrowFunction) {
+      commands[commandsIndex++] = ArrayPrototypeJoin(currentCommand.slice(0, currentCommandIndex), '\n');
+      currentCommandIndex = 0;
+      bracketCount = 0;
+    }
+  }
+
+  if (currentCommandIndex > 0) {
+    commands[commandsIndex++] = ArrayPrototypeJoin(currentCommand.slice(0, currentCommandIndex), '\n');
+  }
+
+  commands.length = commandsIndex;
+  return ArrayPrototypeReverse(commands);
+}
+
+module.exports = { parseHistoryFromFile };
diff --git a/lib/internal/repl/history.js b/lib/internal/repl/history.js
index d8c36170639fc9..84bcbbde212797 100644
--- a/lib/internal/repl/history.js
+++ b/lib/internal/repl/history.js
@@ -2,9 +2,10 @@
 
 const {
   ArrayPrototypeJoin,
+  ArrayPrototypePush,
   Boolean,
   FunctionPrototype,
-  RegExpPrototypeSymbolSplit,
+  StringPrototypeSplit,
   StringPrototypeTrim,
 } = primordials;
 
@@ -17,6 +18,7 @@ let debug = require('internal/util/debuglog').debuglog('repl', (fn) => {
 });
 const permission = require('internal/process/permission');
 const { clearTimeout, setTimeout } = require('timers');
+const { parseHistoryFromFile } = require('internal/repl/history-utils');
 
 const noop = FunctionPrototype;
 
@@ -97,7 +99,7 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
-      repl.history = RegExpPrototypeSymbolSplit(/[\n\r]+/, data, repl.historySize);
+      repl.history = parseHistoryFromFile(data, repl.historySize);
     } else {
       repl.history = [];
     }
@@ -134,6 +136,22 @@ function setupHistory(repl, historyPath, ready) {
     timer = setTimeout(flushHistory, kDebounceHistoryMS);
   }
 
+  function parseHistoryData() {
+    const eol = os.EOL;
+    const result = [];
+    const historyLength = repl.history.length;
+
+    for (let i = 0; i < historyLength; i++) {
+      const entry = repl.history[i];
+      const lines = StringPrototypeSplit(entry, eol);
+      for (let j = lines.length - 1; j >= 0; j--) {
+        ArrayPrototypePush(result, lines[j]);
+      }
+    }
+
+    return ArrayPrototypeJoin(result, eol) + eol;
+  }
+
   function flushHistory() {
     timer = null;
     if (writing) {
@@ -141,7 +159,7 @@ function setupHistory(repl, historyPath, ready) {
       return;
     }
     writing = true;
-    const historyData = ArrayPrototypeJoin(repl.history, os.EOL);
+    const historyData = parseHistoryData();
     fs.write(repl._historyHandle, historyData, 0, 'utf8', onwritten);
   }
 
diff --git a/lib/repl.js b/lib/repl.js
index 6cfceacac620f0..e257e5cddac998 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -117,6 +117,7 @@ const {
 } = require('internal/util');
 const { inspect } = require('internal/util/inspect');
 const vm = require('vm');
+const os = require('os');
 
 const { runInThisContext, runInContext } = vm.Script.prototype;
 
@@ -952,6 +953,14 @@ function REPLServer(prompt,
         self._domain.emit('error', e.err || e);
       }
 
+      if (self[kBufferedCommandSymbol]) {
+        // Remove the first N lines from the self.history array
+        // where N is the number of lines in the buffered command
+        const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], os.EOL);
+        self.history = ArrayPrototypeSlice(self.history, lines.length);
+        // And replace them with the single command divided into lines
+        ArrayPrototypeUnshift(self.history, self[kBufferedCommandSymbol] + cmd);
+      }
       // Clear buffer if no SyntaxErrors
       self.clearBufferedCommand();
       sawCtrlD = false;
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 64317be960e8d1..beef072b784bec 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -236,17 +236,22 @@ const tests = [
     // K = Erase in line; 0 = right; 1 = left; 2 = total
     expected: [
       // 0. Start
-      '\x1B[1G', '\x1B[0J',
-      prompt, '\x1B[3G',
-      // 1. UP
-      // This exceeds the maximum columns (250):
-      // Whitespace + prompt + ' // '.length + 'autocompleteMe'.length
-      // 230 + 2 + 4 + 14
-      '\x1B[1G', '\x1B[0J',
-      `${prompt}${' '.repeat(230)} aut`, '\x1B[237G',
-      ' // ocompleteMe', '\x1B[237G',
-      '\n// 123', '\x1B[237G',
-      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
+      '\x1B[1G',
+      '\x1B[0J',
+      `${prompt}`,
+      '\x1B[3G',
+      '\x1B[1G',
+      '\x1B[0J',
+      `${prompt}aut`,
+      '\x1B[6G',
+      ' // ocompleteMe',
+      '\x1B[6G',
+      '\n// 123',
+      '\x1B[6G',
+      '\x1B[1A',
+      '\x1B[1B',
+      '\x1B[2K',
+      '\x1B[1A',
       '\x1B[0K',
       // 2. UP
       '\x1B[1G', '\x1B[0J',
@@ -633,6 +638,42 @@ const tests = [
     ],
     clean: false
   },
+  {
+    // Test that the multiline history is correctly navigated and it can be edited
+    env: { NODE_REPL_HISTORY: defaultHistoryPath },
+    skip: !process.features.inspector,
+    test: [
+      'let a = ``',
+      ENTER,
+      'a = `I am a multiline strong',
+      ENTER,
+      'which ends here`',
+      ENTER,
+      UP,
+      // press LEFT 19 times to reach the typo
+      ...Array(19).fill(LEFT),
+      BACKSPACE,
+      'i',
+      ENTER,
+    ],
+    expected: [
+      prompt, ...'let a = ``',
+      'undefined\n',
+      prompt, ...'a = `I am a multiline strong',
+      '... ',
+      ...'which ends here`',
+      "'I am a multiline strong\\nwhich ends here'\n",
+      prompt,
+      `${prompt}a = \`I am a multiline strong\nwhich ends here\``,
+      `${prompt}a = \`I am a multiline strong\nwhich ends here\``,
+      `${prompt}a = \`I am a multiline strng\nwhich ends here\``,
+      `${prompt}a = \`I am a multiline string\nwhich ends here\``,
+      `${prompt}a = \`I am a multiline string\nwhich ends here\``,
+      "'I am a multiline string\\nwhich ends here'\n",
+      prompt,
+    ],
+    clean: true
+  },
 ];
 const numtests = tests.length;
 
diff --git a/test/parallel/test-repl-history-utils.js b/test/parallel/test-repl-history-utils.js
new file mode 100644
index 00000000000000..4bd74eae4f6f06
--- /dev/null
+++ b/test/parallel/test-repl-history-utils.js
@@ -0,0 +1,187 @@
+// Flags: --expose-internals
+'use strict';
+
+require('../common');
+
+const assert = require('assert');
+const { parseHistoryFromFile } = require('internal/repl/history-utils');
+
+function reverseString(str) {
+  return str.split('\n').reverse().join('\n');
+}
+
+{
+  // It properly loads a single command
+  const historyFile = "console.log('lello')";
+  const history = parseHistoryFromFile(historyFile);
+
+  assert.deepStrictEqual(history, ['console.log(\'lello\')']);
+}
+
+{
+  // It properly loads a single command on a multiline
+  const historyFile = reverseString("console.log(\n'lello'\n)");
+  const history = parseHistoryFromFile(historyFile);
+
+  assert.deepStrictEqual(history, ['console.log(\n\'lello\'\n)']);
+}
+
+for (const declarator of ['const', 'let', 'var']) {
+  {
+    // It properly loads a multiline string
+    const historyFile = reverseString(`${declarator} a = \`
+I am a multiline string
+With some very interesting content\``);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [
+      `${declarator} a = \`\nI am a multiline string\nWith some very interesting content\``,
+    ]);
+  }
+
+  {
+    // It properly loads a multiline string with fat arrow and plus operator endings
+    const historyFile = reverseString(`${declarator} a = \`
+I am a multiline string +
+With some very interesting content =>
+With special chars here and there\``);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [
+      `${declarator} a = \`\n` +
+      'I am a multiline string +\n' +
+      'With some very interesting content =>\n' +
+      'With special chars here and there`',
+    ]);
+  }
+
+  {
+    // It properly loads a multiline string concatenated with the plus operator
+    const historyFile = reverseString(`${declarator} a = "hello" +
+'world'`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [
+      `${declarator} a = "hello" +\n'world'`,
+    ]);
+  }
+
+  {
+    // It properly loads a multiline object
+    const historyFile = reverseString(`
+${declarator} a = {
+a: 1,
+b: 2,
+c: 3
+}`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ `${declarator} a = {\na: 1,\nb: 2,\nc: 3\n}` ]);
+  }
+
+  {
+    // It properly loads a multiline stringified object
+    const historyFile = reverseString(`\`${declarator} a ={
+    a: 1,
+    b: 2,
+    c: 3,
+    d: [1, 2, 3],
+  }\``);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ `\`${declarator} a ={\n    a: 1,\n    b: 2,\n    c: 3,\n    d: [1, 2, 3],\n  }\`` ]);
+  }
+
+  {
+    // It properly loads a multiline stringified array
+    const historyFile = reverseString(`\`${declarator} b = [
+    1,
+    2,
+    3,
+    4,
+  ]\``);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ `\`${declarator} b = [\n    1,\n    2,\n    3,\n    4,\n  ]\`` ]);
+  }
+
+  {
+    // It properly loads a multiline array
+    const historyFile = reverseString(`${declarator} a = [
+    1,
+    2,
+    3,
+  ]`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ `${declarator} a = [\n    1,\n    2,\n    3,\n  ]` ]);
+  }
+
+  {
+    // It properly loads a multiline complex array of objects
+    const historyFile = reverseString(`\`${declarator} c = [
+  {
+    a: 1,
+    b: 2,
+  },
+  {
+    a: 3,
+    b: 4,
+    c: [
+      1,
+      2,
+      3,
+    ],
+  }
+  ]\``);
+
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [
+      `\`${declarator} c = [\n` +
+      '  {\n' +
+      '    a: 1,\n' +
+      '    b: 2,\n' +
+      '  },\n' +
+      '  {\n' +
+      '    a: 3,\n' +
+      '    b: 4,\n' +
+      '    c: [\n' +
+      '      1,\n' +
+      '      2,\n' +
+      '      3,\n' +
+      '    ],\n' +
+      '  }\n' +
+      '  ]`',
+    ]);
+  }
+
+  {
+    // It properly loads a multiline function
+    const historyFile = reverseString(`function sum(a, b) {
+    return a + b;
+  }`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ 'function sum(a, b) {\n    return a + b;\n  }' ]);
+  }
+
+  {
+    // It properly loads a multiline function as a fat arrow function
+    const historyFile = reverseString(`${declarator} sum = (a, b) =>
+    a + b;`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ `${declarator} sum = (a, b) =>\n    a + b;` ]);
+  }
+
+  {
+    // It properly loads if statements
+    const historyFile = reverseString(`if (true) {
+    console.log('lello');
+  }`);
+    const history = parseHistoryFromFile(historyFile);
+
+    assert.deepStrictEqual(history, [ 'if (true) {\n    console.log(\'lello\');\n  }' ]);
+  }
+}

From 8b261ae4528d10c6dd976a810db53eab297aebb9 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Mon, 10 Mar 2025 14:48:56 +0100
Subject: [PATCH 02/13] repl: do not use the custom parser but split lines with
 \r

---
 benchmark/repl/parse-history-from-file.js     |  97 ---------
 lib/internal/readline/interface.js            |   5 +-
 lib/internal/repl/history-utils.js            |  77 --------
 lib/internal/repl/history.js                  |  24 +--
 lib/repl.js                                   |  19 +-
 test/fixtures/.node_repl_history-multiline    |   4 +
 test/parallel/test-repl-history-navigation.js |  27 ++-
 test/parallel/test-repl-history-utils.js      | 187 ------------------
 .../test-repl-load-multiline-from-history.js  |  90 +++++++++
 9 files changed, 125 insertions(+), 405 deletions(-)
 delete mode 100644 benchmark/repl/parse-history-from-file.js
 delete mode 100644 lib/internal/repl/history-utils.js
 create mode 100644 test/fixtures/.node_repl_history-multiline
 delete mode 100644 test/parallel/test-repl-history-utils.js
 create mode 100644 test/parallel/test-repl-load-multiline-from-history.js

diff --git a/benchmark/repl/parse-history-from-file.js b/benchmark/repl/parse-history-from-file.js
deleted file mode 100644
index 999451e7cbf512..00000000000000
--- a/benchmark/repl/parse-history-from-file.js
+++ /dev/null
@@ -1,97 +0,0 @@
-'use strict';
-
-const common = require('../common.js');
-
-const bench = common.createBenchmark(main, {
-  n: [1e1, 1e2],
-  size: [1e3, 1e4],
-}, {
-  flags: ['--expose-internals'],
-});
-
-const bechText = `
-a ={
-a: 1,
-b: 2,
-}
-
-\`const a ={
-  a: 1,
-  b: 2,
-  c: 3,
-  d: [1, 2, 3],
-}\`
-
-\`const b = [
-  1,
-  2,
-  3,
-  4,
-]\`
-
-const d = [
-  {
-    a: 1,
-    b: 2,
-  },
-  {
-    a: 3,
-    b: 4,
-  }
-]
-
-var e = [
-  {
-    a: 1,
-    b: 2,
-  },
-  {
-    a: 3,
-    b: 4,
-    c: [
-      {
-        a: 1,
-        b: 2,
-      },
-      {
-        a: 3,
-        b: 4,
-      }
-    ]
-  }
-]
-
-a = \`
-I am a multiline string
-I can be as long as I want\`
-
-
-b = \`
-111111111111
-222222222222\`
-
-
-c = \`
-111111=11111
-222222222222\`
-
-function sum(a, b) {
-    return a + b
-}
-
-console.log(
-  'something'
-)
-`;
-
-async function main({ n, size }) {
-  const { parseHistoryFromFile } = require('internal/repl/history-utils');
-
-  bench.start();
-
-  for (let i = 0; i < n; i++) {
-    parseHistoryFromFile(bechText.repeat(size));
-  }
-
-  bench.end(n);
-}
diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index c831c79756f343..9599b728048f8b 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -25,6 +25,7 @@ const {
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
   StringPrototypeRepeat,
+  StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeStartsWith,
   StringPrototypeTrim,
@@ -950,7 +951,7 @@ class Interface extends InterfaceConstructor {
       if (index === -1) {
         this.line = search;
       } else {
-        this.line = this.history[index];
+        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -973,7 +974,7 @@ class Interface extends InterfaceConstructor {
       if (index === this.history.length) {
         this.line = search;
       } else {
-        this.line = this.history[index];
+        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
diff --git a/lib/internal/repl/history-utils.js b/lib/internal/repl/history-utils.js
deleted file mode 100644
index c52988dad42105..00000000000000
--- a/lib/internal/repl/history-utils.js
+++ /dev/null
@@ -1,77 +0,0 @@
-'use strict';
-
-const {
-  Array,
-  ArrayPrototypeJoin,
-  ArrayPrototypeReverse,
-  StringPrototypeCharCodeAt,
-  StringPrototypeTrimEnd,
-} = primordials;
-const os = require('os');
-
-const kBrackets = { '{': 1, '[': 1, '(': 1, '}': -1, ']': -1, ')': -1 };
-
-function parseHistoryFromFile(historyText, historySize) {
-  const lines = historyText.trimEnd().split(os.EOL);
-  let linesLength = lines.length;
-  if (linesLength > historySize) linesLength = historySize;
-
-  const commands = new Array(linesLength);
-  let commandsIndex = 0;
-  const currentCommand = new Array(linesLength);
-  let currentCommandIndex = 0;
-  let bracketCount = 0;
-  let inString = false;
-  let stringDelimiter = '';
-
-  for (let lineIdx = linesLength - 1; lineIdx >= 0; lineIdx--) {
-    const line = lines[lineIdx];
-    currentCommand[currentCommandIndex++] = line;
-
-    let isConcatenation = false;
-    let isArrowFunction = false;
-    let lastChar = '';
-
-    for (let charIdx = 0, len = line.length; charIdx < len; charIdx++) {
-      const char = line[charIdx];
-
-      if ((char === "'" || char === '"' || char === '`') &&
-          (charIdx === 0 || StringPrototypeCharCodeAt(line, charIdx - 1) !== 92)) { // 92 is '\\'
-        if (!inString) {
-          inString = true;
-          stringDelimiter = char;
-        } else if (char === stringDelimiter) {
-          inString = false;
-        }
-      }
-
-      if (!inString) {
-        const bracketValue = kBrackets[char];
-        if (bracketValue) bracketCount += bracketValue;
-      }
-
-      lastChar = char;
-    }
-
-    if (!inString) {
-      const trimmedLine = StringPrototypeTrimEnd(line);
-      isConcatenation = lastChar === '+';
-      isArrowFunction = lastChar === '>' && trimmedLine[trimmedLine.length - 2] === '=';
-    }
-
-    if (!inString && bracketCount <= 0 && !isConcatenation && !isArrowFunction) {
-      commands[commandsIndex++] = ArrayPrototypeJoin(currentCommand.slice(0, currentCommandIndex), '\n');
-      currentCommandIndex = 0;
-      bracketCount = 0;
-    }
-  }
-
-  if (currentCommandIndex > 0) {
-    commands[commandsIndex++] = ArrayPrototypeJoin(currentCommand.slice(0, currentCommandIndex), '\n');
-  }
-
-  commands.length = commandsIndex;
-  return ArrayPrototypeReverse(commands);
-}
-
-module.exports = { parseHistoryFromFile };
diff --git a/lib/internal/repl/history.js b/lib/internal/repl/history.js
index 84bcbbde212797..b6b596939683cd 100644
--- a/lib/internal/repl/history.js
+++ b/lib/internal/repl/history.js
@@ -2,10 +2,9 @@
 
 const {
   ArrayPrototypeJoin,
-  ArrayPrototypePush,
   Boolean,
   FunctionPrototype,
-  StringPrototypeSplit,
+  RegExpPrototypeSymbolSplit,
   StringPrototypeTrim,
 } = primordials;
 
@@ -18,7 +17,6 @@ let debug = require('internal/util/debuglog').debuglog('repl', (fn) => {
 });
 const permission = require('internal/process/permission');
 const { clearTimeout, setTimeout } = require('timers');
-const { parseHistoryFromFile } = require('internal/repl/history-utils');
 
 const noop = FunctionPrototype;
 
@@ -99,7 +97,7 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
-      repl.history = parseHistoryFromFile(data, repl.historySize);
+      repl.history = RegExpPrototypeSymbolSplit(/[\n]+/, data, repl.historySize);
     } else {
       repl.history = [];
     }
@@ -136,22 +134,6 @@ function setupHistory(repl, historyPath, ready) {
     timer = setTimeout(flushHistory, kDebounceHistoryMS);
   }
 
-  function parseHistoryData() {
-    const eol = os.EOL;
-    const result = [];
-    const historyLength = repl.history.length;
-
-    for (let i = 0; i < historyLength; i++) {
-      const entry = repl.history[i];
-      const lines = StringPrototypeSplit(entry, eol);
-      for (let j = lines.length - 1; j >= 0; j--) {
-        ArrayPrototypePush(result, lines[j]);
-      }
-    }
-
-    return ArrayPrototypeJoin(result, eol) + eol;
-  }
-
   function flushHistory() {
     timer = null;
     if (writing) {
@@ -159,7 +141,7 @@ function setupHistory(repl, historyPath, ready) {
       return;
     }
     writing = true;
-    const historyData = parseHistoryData();
+    const historyData = ArrayPrototypeJoin(repl.history, os.EOL);
     fs.write(repl._historyHandle, historyData, 0, 'utf8', onwritten);
   }
 
diff --git a/lib/repl.js b/lib/repl.js
index e257e5cddac998..c638d6b90c54fe 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -83,7 +83,9 @@ const {
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
   StringPrototypeIncludes,
+  StringPrototypeIndexOf,
   StringPrototypeRepeat,
+  StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeSplit,
   StringPrototypeStartsWith,
@@ -117,7 +119,6 @@ const {
 } = require('internal/util');
 const { inspect } = require('internal/util/inspect');
 const vm = require('vm');
-const os = require('os');
 
 const { runInThisContext, runInContext } = vm.Script.prototype;
 
@@ -953,14 +954,22 @@ function REPLServer(prompt,
         self._domain.emit('error', e.err || e);
       }
 
-      if (self[kBufferedCommandSymbol]) {
+      // In the next two if blocks, we do not use os.EOL instead of '\n'
+      // because on Windows it is '\r\n'
+      if (cmd && StringPrototypeIndexOf(cmd, '\n') !== -1) { // If you are editing a multiline command
+        self.history[0] = StringPrototypeReplaceAll(cmd, '\n', '\r');
+      } else if (self[kBufferedCommandSymbol]) { // If a new multiline command was entered
         // Remove the first N lines from the self.history array
         // where N is the number of lines in the buffered command
-        const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], os.EOL);
+
+        const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
         self.history = ArrayPrototypeSlice(self.history, lines.length);
-        // And replace them with the single command divided into lines
-        ArrayPrototypeUnshift(self.history, self[kBufferedCommandSymbol] + cmd);
+        ArrayPrototypePop(lines);
+        // And replace them with the single command split by '\r'
+        ArrayPrototypePush(lines, cmd);
+        ArrayPrototypeUnshift(self.history, ArrayPrototypeJoin(lines, '\r'));
       }
+
       // Clear buffer if no SyntaxErrors
       self.clearBufferedCommand();
       sawCtrlD = false;
diff --git a/test/fixtures/.node_repl_history-multiline b/test/fixtures/.node_repl_history-multiline
new file mode 100644
index 00000000000000..c7e45f0154fdb4
--- /dev/null
+++ b/test/fixtures/.node_repl_history-multiline
@@ -0,0 +1,4 @@
+var d = [
  {
    a: 1,
    b: 2,
  },
  {
    a: 3,
    b: 4,
    c: [{ a: 1, b: 2 },
      {
        a: 3,
        b: 4,
      }
    ]
  }
]
+const c = [
  {
    a: 1,
    b: 2,
  }
]
+`const b = [
  1,
  2,
  3,
  4,
]`
+a = `
I am a multiline string
I can be as long as I want`
\ No newline at end of file
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index beef072b784bec..88493beb3f9ae3 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -236,22 +236,17 @@ const tests = [
     // K = Erase in line; 0 = right; 1 = left; 2 = total
     expected: [
       // 0. Start
-      '\x1B[1G',
-      '\x1B[0J',
-      `${prompt}`,
-      '\x1B[3G',
-      '\x1B[1G',
-      '\x1B[0J',
-      `${prompt}aut`,
-      '\x1B[6G',
-      ' // ocompleteMe',
-      '\x1B[6G',
-      '\n// 123',
-      '\x1B[6G',
-      '\x1B[1A',
-      '\x1B[1B',
-      '\x1B[2K',
-      '\x1B[1A',
+      '\x1B[1G', '\x1B[0J',
+      prompt, '\x1B[3G',
+      // 1. UP
+      // This exceeds the maximum columns (250):
+      // Whitespace + prompt + ' // '.length + 'autocompleteMe'.length
+      // 230 + 2 + 4 + 14
+      '\x1B[1G', '\x1B[0J',
+      `${prompt}${' '.repeat(230)} aut`, '\x1B[237G',
+      ' // ocompleteMe', '\x1B[237G',
+      '\n// 123', '\x1B[237G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       '\x1B[0K',
       // 2. UP
       '\x1B[1G', '\x1B[0J',
diff --git a/test/parallel/test-repl-history-utils.js b/test/parallel/test-repl-history-utils.js
deleted file mode 100644
index 4bd74eae4f6f06..00000000000000
--- a/test/parallel/test-repl-history-utils.js
+++ /dev/null
@@ -1,187 +0,0 @@
-// Flags: --expose-internals
-'use strict';
-
-require('../common');
-
-const assert = require('assert');
-const { parseHistoryFromFile } = require('internal/repl/history-utils');
-
-function reverseString(str) {
-  return str.split('\n').reverse().join('\n');
-}
-
-{
-  // It properly loads a single command
-  const historyFile = "console.log('lello')";
-  const history = parseHistoryFromFile(historyFile);
-
-  assert.deepStrictEqual(history, ['console.log(\'lello\')']);
-}
-
-{
-  // It properly loads a single command on a multiline
-  const historyFile = reverseString("console.log(\n'lello'\n)");
-  const history = parseHistoryFromFile(historyFile);
-
-  assert.deepStrictEqual(history, ['console.log(\n\'lello\'\n)']);
-}
-
-for (const declarator of ['const', 'let', 'var']) {
-  {
-    // It properly loads a multiline string
-    const historyFile = reverseString(`${declarator} a = \`
-I am a multiline string
-With some very interesting content\``);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [
-      `${declarator} a = \`\nI am a multiline string\nWith some very interesting content\``,
-    ]);
-  }
-
-  {
-    // It properly loads a multiline string with fat arrow and plus operator endings
-    const historyFile = reverseString(`${declarator} a = \`
-I am a multiline string +
-With some very interesting content =>
-With special chars here and there\``);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [
-      `${declarator} a = \`\n` +
-      'I am a multiline string +\n' +
-      'With some very interesting content =>\n' +
-      'With special chars here and there`',
-    ]);
-  }
-
-  {
-    // It properly loads a multiline string concatenated with the plus operator
-    const historyFile = reverseString(`${declarator} a = "hello" +
-'world'`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [
-      `${declarator} a = "hello" +\n'world'`,
-    ]);
-  }
-
-  {
-    // It properly loads a multiline object
-    const historyFile = reverseString(`
-${declarator} a = {
-a: 1,
-b: 2,
-c: 3
-}`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ `${declarator} a = {\na: 1,\nb: 2,\nc: 3\n}` ]);
-  }
-
-  {
-    // It properly loads a multiline stringified object
-    const historyFile = reverseString(`\`${declarator} a ={
-    a: 1,
-    b: 2,
-    c: 3,
-    d: [1, 2, 3],
-  }\``);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ `\`${declarator} a ={\n    a: 1,\n    b: 2,\n    c: 3,\n    d: [1, 2, 3],\n  }\`` ]);
-  }
-
-  {
-    // It properly loads a multiline stringified array
-    const historyFile = reverseString(`\`${declarator} b = [
-    1,
-    2,
-    3,
-    4,
-  ]\``);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ `\`${declarator} b = [\n    1,\n    2,\n    3,\n    4,\n  ]\`` ]);
-  }
-
-  {
-    // It properly loads a multiline array
-    const historyFile = reverseString(`${declarator} a = [
-    1,
-    2,
-    3,
-  ]`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ `${declarator} a = [\n    1,\n    2,\n    3,\n  ]` ]);
-  }
-
-  {
-    // It properly loads a multiline complex array of objects
-    const historyFile = reverseString(`\`${declarator} c = [
-  {
-    a: 1,
-    b: 2,
-  },
-  {
-    a: 3,
-    b: 4,
-    c: [
-      1,
-      2,
-      3,
-    ],
-  }
-  ]\``);
-
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [
-      `\`${declarator} c = [\n` +
-      '  {\n' +
-      '    a: 1,\n' +
-      '    b: 2,\n' +
-      '  },\n' +
-      '  {\n' +
-      '    a: 3,\n' +
-      '    b: 4,\n' +
-      '    c: [\n' +
-      '      1,\n' +
-      '      2,\n' +
-      '      3,\n' +
-      '    ],\n' +
-      '  }\n' +
-      '  ]`',
-    ]);
-  }
-
-  {
-    // It properly loads a multiline function
-    const historyFile = reverseString(`function sum(a, b) {
-    return a + b;
-  }`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ 'function sum(a, b) {\n    return a + b;\n  }' ]);
-  }
-
-  {
-    // It properly loads a multiline function as a fat arrow function
-    const historyFile = reverseString(`${declarator} sum = (a, b) =>
-    a + b;`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ `${declarator} sum = (a, b) =>\n    a + b;` ]);
-  }
-
-  {
-    // It properly loads if statements
-    const historyFile = reverseString(`if (true) {
-    console.log('lello');
-  }`);
-    const history = parseHistoryFromFile(historyFile);
-
-    assert.deepStrictEqual(history, [ 'if (true) {\n    console.log(\'lello\');\n  }' ]);
-  }
-}
diff --git a/test/parallel/test-repl-load-multiline-from-history.js b/test/parallel/test-repl-load-multiline-from-history.js
new file mode 100644
index 00000000000000..dc806d047ab16c
--- /dev/null
+++ b/test/parallel/test-repl-load-multiline-from-history.js
@@ -0,0 +1,90 @@
+'use strict';
+
+// Flags: --expose-internals
+
+const common = require('../common');
+
+const assert = require('assert');
+const repl = require('internal/repl');
+const stream = require('stream');
+const fixtures = require('../common/fixtures');
+
+class ActionStream extends stream.Stream {
+  run(data) {
+    const _iter = data[Symbol.iterator]();
+    const doAction = () => {
+      const next = _iter.next();
+      if (next.done) {
+        // Close the repl. Note that it must have a clean prompt to do so.
+        this.emit('keypress', '', { ctrl: true, name: 'd' });
+        return;
+      }
+      const action = next.value;
+
+      if (typeof action === 'object') {
+        this.emit('keypress', '', action);
+      }
+      setImmediate(doAction);
+    };
+    doAction();
+  }
+  resume() {}
+  pause() {}
+}
+ActionStream.prototype.readable = true;
+
+{
+  // Testing multiline history loading
+  const tmpdir = require('../common/tmpdir');
+  tmpdir.refresh();
+  const replHistoryPath = fixtures.path('.node_repl_history-multiline');
+
+  const checkResults = common.mustSucceed((r) => {
+    assert.strictEqual(r.history.length, 4);
+
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(
+      r.line,
+      'var d = [\n' +
+    '  {\n' +
+    '    a: 1,\n' +
+    '    b: 2,\n' +
+    '  },\n' +
+    '  {\n' +
+    '    a: 3,\n' +
+    '    b: 4,\n' +
+    '    c: [{ a: 1, b: 2 },\n' +
+    '      {\n' +
+    '        a: 3,\n' +
+    '        b: 4,\n' +
+    '      }\n' +
+    '    ]\n' +
+    '  }\n' +
+    ']'
+    );
+
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.line, 'const c = [\n  {\n    a: 1,\n    b: 2,\n  }\n]');
+
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.line, '`const b = [\n  1,\n  2,\n  3,\n  4,\n]`');
+
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.line, 'a = `\nI am a multiline string\nI can be as long as I want`');
+
+  });
+
+  repl.createInternalRepl(
+    { NODE_REPL_HISTORY: replHistoryPath },
+    {
+      terminal: true,
+      input: new ActionStream(),
+      output: new stream.Writable({
+        write(chunk, _, next) {
+          next();
+        }
+      }),
+    },
+    checkResults
+  );
+}

From 306ee84635bc602b6148dc07e21644efa670925a Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Tue, 18 Mar 2025 10:18:30 +0100
Subject: [PATCH 03/13] repl: replace ... with | and navigate multiline history
 with up / down

---
 lib/internal/readline/interface.js            | 55 +++++++++++-
 lib/repl.js                                   |  2 +-
 test/parallel/test-repl-history-navigation.js | 53 +++++++++++-
 .../test-repl-load-multiline-from-history.js  | 12 ++-
 test/parallel/test-repl-multiline.js          |  2 +-
 test/parallel/test-repl-recoverable.js        |  2 +-
 test/parallel/test-repl-top-level-await.js    | 20 ++---
 .../test-repl-unexpected-token-recoverable.js |  2 +-
 test/parallel/test-repl.js                    | 84 +++++++++----------
 9 files changed, 168 insertions(+), 64 deletions(-)

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 9599b728048f8b..eec9a25fd94e1f 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -24,9 +24,11 @@ const {
   SafeStringIterator,
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
+  StringPrototypeIndexOf,
   StringPrototypeRepeat,
   StringPrototypeReplaceAll,
   StringPrototypeSlice,
+  StringPrototypeSplit,
   StringPrototypeStartsWith,
   StringPrototypeTrim,
   Symbol,
@@ -100,7 +102,9 @@ const kDeleteWordLeft = Symbol('_deleteWordLeft');
 const kDeleteWordRight = Symbol('_deleteWordRight');
 const kGetDisplayPos = Symbol('_getDisplayPos');
 const kHistoryNext = Symbol('_historyNext');
+const kMoveDownOrHistoryNext = Symbol('_moveDownOrHistoryNext');
 const kHistoryPrev = Symbol('_historyPrev');
+const kMoveUpOrHistoryPrev = Symbol('_moveUpOrHistoryPrev');
 const kInsertString = Symbol('_insertString');
 const kLine = Symbol('_line');
 const kLine_buffer = Symbol('_line_buffer');
@@ -929,6 +933,26 @@ class Interface extends InterfaceConstructor {
     this[kRefreshLine]();
   }
 
+  [kMoveDownOrHistoryNext]() {
+    const { cols, rows } = this.getCursorPos();
+    const splitLine = StringPrototypeSplit(this.line, '\n');
+    // Go to the next history only if the cursor is in the first line of the multiline input.
+    // Otherwise treat the "arrow down" as a movement to the next row.
+    if (splitLine.length > 1 && rows < splitLine.length - 1) {
+      const currentLine = splitLine[rows];
+      const nextLine = splitLine[rows + 1];
+      const amountToMove = (cols > nextLine.length) ?
+        +cols + nextLine.length - 1 :
+        +currentLine.length + 1;
+      // Go to the same position on the next line, or the end of the next line
+      // If the current position does not exist in the next line.
+      this[kMoveCursor](amountToMove);
+      return;
+    }
+
+    this[kHistoryNext]();
+  }
+
   // TODO(BridgeAR): Add underscores to the search part and a red background in
   // case no match is found. This should only be the visual part and not the
   // actual line content!
@@ -939,7 +963,9 @@ class Interface extends InterfaceConstructor {
   [kHistoryNext]() {
     if (this.historyIndex >= 0) {
       this[kBeforeEdit](this.line, this.cursor);
-      const search = this[kSubstringSearch] || '';
+      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
+
+      const search = isLineMultiline ? '' : this[kSubstringSearch] || '';
       let index = this.historyIndex - 1;
       while (
         index >= 0 &&
@@ -959,10 +985,31 @@ class Interface extends InterfaceConstructor {
     }
   }
 
+  [kMoveUpOrHistoryPrev]() {
+    const { cols, rows } = this.getCursorPos();
+    const splitLine = StringPrototypeSplit(this.line, '\n');
+    // Go to the previous history only if the cursor is in the first line of the multiline input.
+    // Otherwise treat the "arrow up" as a movement to the previous row.
+    if (splitLine.length > 1 && rows > 0) {
+      const previousLine = splitLine[rows - 1];
+      const amountToMove = (cols > previousLine.length) ?
+        -cols - 1 :
+        -previousLine.length - 1;
+      // Go to the same position on the previous line, or the end of the previous line
+      // If the current position does not exist in the previous line.
+      this[kMoveCursor](amountToMove);
+      return;
+    }
+
+    this[kHistoryPrev]();
+  }
+
   [kHistoryPrev]() {
     if (this.historyIndex < this.history.length && this.history.length) {
       this[kBeforeEdit](this.line, this.cursor);
-      const search = this[kSubstringSearch] || '';
+      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
+
+      const search = isLineMultiline ? '' : this[kSubstringSearch] || '';
       let index = this.historyIndex + 1;
       while (
         index < this.history.length &&
@@ -1309,11 +1356,11 @@ class Interface extends InterfaceConstructor {
           break;
 
         case 'up':
-          this[kHistoryPrev]();
+          this[kMoveUpOrHistoryPrev]();
           break;
 
         case 'down':
-          this[kHistoryNext]();
+          this[kMoveDownOrHistoryNext]();
           break;
 
         case 'tab':
diff --git a/lib/repl.js b/lib/repl.js
index c638d6b90c54fe..89a0f83d10b911 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -1207,7 +1207,7 @@ REPLServer.prototype.resetContext = function() {
 REPLServer.prototype.displayPrompt = function(preserveCursor) {
   let prompt = this._initialPrompt;
   if (this[kBufferedCommandSymbol].length) {
-    prompt = '...';
+    prompt = '|';
     const len = this.lines.level.length ? this.lines.level.length - 1 : 0;
     const levelInd = StringPrototypeRepeat('..', len);
     prompt += levelInd + ' ';
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 88493beb3f9ae3..3116bc027ceae3 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -655,7 +655,7 @@ const tests = [
       prompt, ...'let a = ``',
       'undefined\n',
       prompt, ...'a = `I am a multiline strong',
-      '... ',
+      '| ',
       ...'which ends here`',
       "'I am a multiline strong\\nwhich ends here'\n",
       prompt,
@@ -669,6 +669,57 @@ const tests = [
     ],
     clean: true
   },
+  {
+    // Test that the previous multiline history can only be accessed going through the entirety of the current
+    // One navigating its all lines first.
+    env: { NODE_REPL_HISTORY: defaultHistoryPath },
+    skip: !process.features.inspector,
+    test: [
+      'let b = ``',
+      ENTER,
+      'b = `I am a multiline strong',
+      ENTER,
+      'which ends here`',
+      ENTER,
+      'let c = `I',
+      ENTER,
+      'am another one`',
+      ENTER,
+      UP,
+      UP,
+      UP,
+      UP,
+      // press RIGHT 10 times to reach the typo
+      ...Array(10).fill(RIGHT),
+      BACKSPACE,
+      'i',
+      ENTER,
+    ],
+    expected: [
+      prompt, ...'let b = ``',
+      'undefined\n',
+      prompt, ...'b = `I am a multiline strong',
+      '| ',
+      ...'which ends here`',
+      "'I am a multiline strong\\nwhich ends here'\n",
+      prompt, ...'let c = `I',
+      '| ',
+      ...'am another one`',
+      'undefined\n',
+      prompt,
+      `${prompt}let c = \`I\nam another one\``,
+      `${prompt}let c = \`I\nam another one\``,
+
+      `${prompt}b = \`I am a multiline strong\nwhich ends here\``,
+      `${prompt}b = \`I am a multiline strong\nwhich ends here\``,
+      `${prompt}b = \`I am a multiline strng\nwhich ends here\``,
+      `${prompt}b = \`I am a multiline string\nwhich ends here\``,
+      `${prompt}b = \`I am a multiline string\nwhich ends here\``,
+      "'I am a multiline string\\nwhich ends here'\n",
+      prompt,
+    ],
+    clean: true
+  },
 ];
 const numtests = tests.length;
 
diff --git a/test/parallel/test-repl-load-multiline-from-history.js b/test/parallel/test-repl-load-multiline-from-history.js
index dc806d047ab16c..0998d664fa0bd1 100644
--- a/test/parallel/test-repl-load-multiline-from-history.js
+++ b/test/parallel/test-repl-load-multiline-from-history.js
@@ -63,13 +63,19 @@ ActionStream.prototype.readable = true;
     ']'
     );
 
-    r.input.run([{ name: 'up' }]);
+    for (let i = 0; i < r.line.split('\n').length; i++) {
+      r.input.run([{ name: 'up' }]);
+    }
     assert.strictEqual(r.line, 'const c = [\n  {\n    a: 1,\n    b: 2,\n  }\n]');
 
-    r.input.run([{ name: 'up' }]);
+    for (let i = 0; i < r.line.split('\n').length; i++) {
+      r.input.run([{ name: 'up' }]);
+    }
     assert.strictEqual(r.line, '`const b = [\n  1,\n  2,\n  3,\n  4,\n]`');
 
-    r.input.run([{ name: 'up' }]);
+    for (let i = 0; i < r.line.split('\n').length; i++) {
+      r.input.run([{ name: 'up' }]);
+    }
     assert.strictEqual(r.line, 'a = `\nI am a multiline string\nI can be as long as I want`');
 
   });
diff --git a/test/parallel/test-repl-multiline.js b/test/parallel/test-repl-multiline.js
index e458555cd87f76..0a2f95668a1683 100644
--- a/test/parallel/test-repl-multiline.js
+++ b/test/parallel/test-repl-multiline.js
@@ -26,7 +26,7 @@ function run({ useColors }) {
     // Validate the output, which contains terminal escape codes.
     assert.strictEqual(actual.length, 6);
     assert.ok(actual[0].endsWith(input[0]));
-    assert.ok(actual[1].includes('... '));
+    assert.ok(actual[1].includes('| '));
     assert.ok(actual[1].endsWith(input[1]));
     assert.ok(actual[2].includes('undefined'));
     assert.ok(actual[3].endsWith(input[2]));
diff --git a/test/parallel/test-repl-recoverable.js b/test/parallel/test-repl-recoverable.js
index a975dac782cfe4..74dcd5dfbf585d 100644
--- a/test/parallel/test-repl-recoverable.js
+++ b/test/parallel/test-repl-recoverable.js
@@ -18,7 +18,7 @@ function customEval(code, context, file, cb) {
 const putIn = new ArrayStream();
 
 putIn.write = function(msg) {
-  if (msg === '... ') {
+  if (msg === '| ') {
     recovered = true;
   }
 
diff --git a/test/parallel/test-repl-top-level-await.js b/test/parallel/test-repl-top-level-await.js
index c8bc26fad62e5c..e07b27948b93d8 100644
--- a/test/parallel/test-repl-top-level-await.js
+++ b/test/parallel/test-repl-top-level-await.js
@@ -96,7 +96,7 @@ async function ordinaryTests() {
     ['const m = foo(await koo());'],
     ['m', '4'],
     ['const n = foo(await\nkoo());',
-     ['const n = foo(await\r', '... koo());\r', 'undefined']],
+     ['const n = foo(await\r', '| koo());\r', 'undefined']],
     ['n', '4'],
     // eslint-disable-next-line no-template-curly-in-string
     ['`status: ${(await Promise.resolve({ status: 200 })).status}`',
@@ -145,20 +145,20 @@ async function ordinaryTests() {
     ],
     ['for (const x of [1,2,3]) {\nawait x\n}', [
       'for (const x of [1,2,3]) {\r',
-      '... await x\r',
-      '... }\r',
+      '| await x\r',
+      '| }\r',
       'undefined',
     ]],
     ['for (const x of [1,2,3]) {\nawait x;\n}', [
       'for (const x of [1,2,3]) {\r',
-      '... await x;\r',
-      '... }\r',
+      '| await x;\r',
+      '| }\r',
       'undefined',
     ]],
     ['for await (const x of [1,2,3]) {\nconsole.log(x)\n}', [
       'for await (const x of [1,2,3]) {\r',
-      '... console.log(x)\r',
-      '... }\r',
+      '| console.log(x)\r',
+      '| }\r',
       '1',
       '2',
       '3',
@@ -166,8 +166,8 @@ async function ordinaryTests() {
     ]],
     ['for await (const x of [1,2,3]) {\nconsole.log(x);\n}', [
       'for await (const x of [1,2,3]) {\r',
-      '... console.log(x);\r',
-      '... }\r',
+      '| console.log(x);\r',
+      '| }\r',
       '1',
       '2',
       '3',
@@ -192,7 +192,7 @@ async function ordinaryTests() {
     } else if ('line' in options) {
       assert.strictEqual(lines[toBeRun.length + options.line], expected);
     } else {
-      const echoed = toBeRun.map((a, i) => `${i > 0 ? '... ' : ''}${a}\r`);
+      const echoed = toBeRun.map((a, i) => `${i > 0 ? '| ' : ''}${a}\r`);
       assert.deepStrictEqual(lines, [...echoed, expected, PROMPT]);
     }
   }
diff --git a/test/parallel/test-repl-unexpected-token-recoverable.js b/test/parallel/test-repl-unexpected-token-recoverable.js
index ddab589ddec8b9..2f3bd38d809303 100644
--- a/test/parallel/test-repl-unexpected-token-recoverable.js
+++ b/test/parallel/test-repl-unexpected-token-recoverable.js
@@ -12,7 +12,7 @@ const child = spawn(process.execPath, args);
 
 const input = 'const foo = "bar\\\nbaz"';
 // Match '...' as well since it marks a multi-line statement
-const expectOut = /> \.\.\. undefined\n/;
+const expectOut = /> \| undefined\n/;
 
 child.stderr.setEncoding('utf8');
 child.stderr.on('data', (d) => {
diff --git a/test/parallel/test-repl.js b/test/parallel/test-repl.js
index 6c16d2a9679b21..9f14ebb39eeac7 100644
--- a/test/parallel/test-repl.js
+++ b/test/parallel/test-repl.js
@@ -69,7 +69,7 @@ async function runReplTests(socket, prompt, tests) {
 
         // Allow to match partial text if no newline was received, because
         // sending newlines from the REPL itself would be redundant
-        // (e.g. in the `... ` multiline prompt: The user already pressed
+        // (e.g. in the `| ` multiline prompt: The user already pressed
         // enter for that, so the REPL shouldn't do it again!).
         if (lineBuffer === expectedLine && !expectedLine.includes('\n'))
           lineBuffer += '\n';
@@ -154,7 +154,7 @@ const errorTests = [
   // Common syntax error is treated as multiline command
   {
     send: 'function test_func() {',
-    expect: '... '
+    expect: '| '
   },
   // You can recover with the .break command
   {
@@ -169,7 +169,7 @@ const errorTests = [
   // Can handle multiline template literals
   {
     send: '`io.js',
-    expect: '... '
+    expect: '| '
   },
   // Special REPL commands still available
   {
@@ -179,7 +179,7 @@ const errorTests = [
   // Template expressions
   {
     send: '`io.js ${"1.0"',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '+ ".2"}`',
@@ -187,7 +187,7 @@ const errorTests = [
   },
   {
     send: '`io.js ${',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '"1.0" + ".2"}`',
@@ -196,7 +196,7 @@ const errorTests = [
   // Dot prefix in multiline commands aren't treated as commands
   {
     send: '("a"',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '.charAt(0))',
@@ -330,7 +330,7 @@ const errorTests = [
   // Multiline object
   {
     send: '{ a: ',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '1 }',
@@ -339,7 +339,7 @@ const errorTests = [
   // Multiline string-keyed object (e.g. JSON)
   {
     send: '{ "a": ',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '1 }',
@@ -348,12 +348,12 @@ const errorTests = [
   // Multiline class with private member.
   {
     send: 'class Foo { #private = true ',
-    expect: '... '
+    expect: '| '
   },
   // Class field with bigint.
   {
     send: 'num = 123456789n',
-    expect: '... '
+    expect: '| '
   },
   // Static class features.
   {
@@ -363,15 +363,15 @@ const errorTests = [
   // Multiline anonymous function with comment
   {
     send: '(function() {',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '// blah',
-    expect: '... '
+    expect: '| '
   },
   {
     send: 'return 1n;',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '})()',
@@ -380,11 +380,11 @@ const errorTests = [
   // Multiline function call
   {
     send: 'function f(){}; f(f(1,',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '2)',
-    expect: '... '
+    expect: '| '
   },
   {
     send: ')',
@@ -405,16 +405,16 @@ const errorTests = [
   ...possibleTokensAfterIdentifierWithLineBreak.map((token) => (
     {
       send: `npm ${token}; undefined`,
-      expect: '... undefined'
+      expect: '| undefined'
     }
   )),
   {
     send: '(function() {\n\nreturn 1;\n})()',
-    expect: '... ... ... 1'
+    expect: '| | | 1'
   },
   {
     send: '{\n\na: 1\n}',
-    expect: '... ... ... { a: 1 }'
+    expect: '| | | { a: 1 }'
   },
   {
     send: 'url.format("http://google.com")',
@@ -449,7 +449,7 @@ const errorTests = [
   // Do not fail when a String is created with line continuation
   {
     send: '\'the\\\nfourth\\\neye\'',
-    expect: ['... ... \'thefourtheye\'']
+    expect: ['| | \'thefourtheye\'']
   },
   // Don't fail when a partial String is created and line continuation is used
   // with whitespace characters at the end of the string. We are to ignore it.
@@ -462,17 +462,17 @@ const errorTests = [
   // Multiline strings preserve whitespace characters in them
   {
     send: '\'the \\\n   fourth\t\t\\\n  eye  \'',
-    expect: '... ... \'the    fourth\\t\\t  eye  \''
+    expect: '| | \'the    fourth\\t\\t  eye  \''
   },
   // More than one multiline strings also should preserve whitespace chars
   {
     send: '\'the \\\n   fourth\' +  \'\t\t\\\n  eye  \'',
-    expect: '... ... \'the    fourth\\t\\t  eye  \''
+    expect: '| | \'the    fourth\\t\\t  eye  \''
   },
   // using REPL commands within a string literal should still work
   {
     send: '\'\\\n.break',
-    expect: '... ' + prompt_unix
+    expect: '| ' + prompt_unix
   },
   // Using REPL command "help" within a string literal should still work
   {
@@ -519,7 +519,7 @@ const errorTests = [
   // Empty lines in the string literals should not affect the string
   {
     send: '\'the\\\n\\\nfourtheye\'\n',
-    expect: '... ... \'thefourtheye\''
+    expect: '| | \'thefourtheye\''
   },
   // Regression test for https://github.com/nodejs/node/issues/597
   {
@@ -536,32 +536,32 @@ const errorTests = [
   // Regression tests for https://github.com/nodejs/node/issues/2749
   {
     send: 'function x() {\nreturn \'\\n\';\n }',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x() {\nreturn \'\\\\\';\n }',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   // Regression tests for https://github.com/nodejs/node/issues/3421
   {
     send: 'function x() {\n//\'\n }',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x() {\n//"\n }',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x() {//\'\n }',
-    expect: '... undefined'
+    expect: '| undefined'
   },
   {
     send: 'function x() {//"\n }',
-    expect: '... undefined'
+    expect: '| undefined'
   },
   {
     send: 'function x() {\nvar i = "\'";\n }',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x(/*optional*/) {}',
@@ -589,7 +589,7 @@ const errorTests = [
   },
   {
     send: '/* \'\n"\n\'"\'\n*/',
-    expect: '... ... ... undefined'
+    expect: '| | | undefined'
   },
   // REPL should get a normal require() function, not one that allows
   // access to internal modules without the --expose-internals flag.
@@ -614,19 +614,19 @@ const errorTests = [
   // REPL should handle quotes within regexp literal in multiline mode
   {
     send: "function x(s) {\nreturn s.replace(/'/,'');\n}",
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: "function x(s) {\nreturn s.replace(/'/,'');\n}",
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x(s) {\nreturn s.replace(/"/,"");\n}',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: 'function x(s) {\nreturn s.replace(/.*/,"");\n}',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
   {
     send: '{ var x = 4; }',
@@ -697,17 +697,17 @@ const errorTests = [
   // https://github.com/nodejs/node/issues/9300
   {
     send: 'function foo() {\nvar bar = 1 / 1; // "/"\n}',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
 
   {
     send: '(function() {\nreturn /foo/ / /bar/;\n}())',
-    expect: '... ... NaN'
+    expect: '| | NaN'
   },
 
   {
     send: '(function() {\nif (false) {} /bar"/;\n}())',
-    expect: '... ... undefined'
+    expect: '| | undefined'
   },
 
   // https://github.com/nodejs/node/issues/16483
@@ -723,7 +723,7 @@ const errorTests = [
   // Newline within template string maintains whitespace.
   {
     send: '`foo \n`',
-    expect: '... \'foo \\n\''
+    expect: '| \'foo \\n\''
   },
   // Whitespace is not evaluated.
   {
@@ -757,7 +757,7 @@ const errorTests = [
   {
     send: 'x = {\nfield\n{',
     expect: [
-      '... ... {',
+      '| | {',
       kArrow,
       '',
       /^Uncaught SyntaxError: /,
@@ -774,11 +774,11 @@ const errorTests = [
   },
   {
     send: 'if (typeof process === "object"); {',
-    expect: '... '
+    expect: '| '
   },
   {
     send: 'console.log("process is defined");',
-    expect: '... '
+    expect: '| '
   },
   {
     send: '} else {',

From 96fb15628241bb175cdb5e0417882b483db2f576 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Tue, 18 Mar 2025 10:48:31 +0100
Subject: [PATCH 04/13] repl: recover lines with syntax errors in history

---
 lib/repl.js                                   |  5 +-
 test/parallel/test-repl-history-navigation.js | 48 +++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/lib/repl.js b/lib/repl.js
index 89a0f83d10b911..4ec7fcdd23dd6a 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -951,7 +951,6 @@ function REPLServer(prompt,
           self.displayPrompt();
           return;
         }
-        self._domain.emit('error', e.err || e);
       }
 
       // In the next two if blocks, we do not use os.EOL instead of '\n'
@@ -970,6 +969,10 @@ function REPLServer(prompt,
         ArrayPrototypeUnshift(self.history, ArrayPrototypeJoin(lines, '\r'));
       }
 
+      if (e) {
+        self._domain.emit('error', e.err || e);
+      }
+
       // Clear buffer if no SyntaxErrors
       self.clearBufferedCommand();
       sawCtrlD = false;
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 3116bc027ceae3..1c043e5eff0adc 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -720,6 +720,53 @@ const tests = [
     ],
     clean: true
   },
+  {
+    // Test that we can recover from a line with a syntax error
+    env: { NODE_REPL_HISTORY: defaultHistoryPath },
+    skip: !process.features.inspector,
+    test: [
+      'let d = ``',
+      ENTER,
+      'd = `I am a',
+      ENTER,
+      'super',
+      ENTER,
+      'broken` line\'',
+      ENTER,
+      UP,
+      BACKSPACE,
+      '`',
+      // press LEFT 6 times to reach the typo
+      ...Array(6).fill(LEFT),
+      BACKSPACE,
+      ENTER,
+    ],
+    expected: [
+      prompt, ...'let d = ``',
+      'undefined\n',
+      prompt, ...'d = `I am a',
+      '| ',
+      ...'super',
+      '| ',
+      ...'broken` line\'',
+      "[broken` line'\n" +
+      '        ^^^^\n' +
+      '\n' +
+      "Uncaught SyntaxError: Unexpected identifier 'line'\n" +
+      '] {\n' +
+      '  [stack]: [Getter/Setter],\n' +
+      `  [message]: "Unexpected identifier 'line'"\n` +
+      '}\n',
+      prompt,
+      `${prompt}d = \`I am a\nsuper\nbroken\` line'`,
+      `${prompt}d = \`I am a\nsuper\nbroken\` line`,
+      '`',
+      `${prompt}d = \`I am a\nsuper\nbroken line\``,
+      "'I am a\\nsuper\\nbroken line'\n",
+      prompt,
+    ],
+    clean: true
+  },
 ];
 const numtests = tests.length;
 
@@ -767,6 +814,7 @@ function runTest() {
           try {
             assert.strictEqual(output, expected[i]);
           } catch (e) {
+            console.log({ output, expected: expected[i] });
             console.error(`Failed test # ${numtests - tests.length}`);
             console.error('Last outputs: ' + inspect(lastChunks, {
               breakLength: 5, colors: true

From 27412587a1b4f338cb871be3af827806d5fb0f7f Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Tue, 18 Mar 2025 11:34:03 +0100
Subject: [PATCH 05/13] repl: consider removeHistoryDuplicates when saving
 multiline history

---
 lib/internal/readline/interface.js            | 24 +++--
 lib/repl.js                                   |  5 +-
 test/parallel/test-repl-history-navigation.js | 24 ++++-
 .../test-repl-multiline-navigation.js         | 94 +++++++++++++++++++
 4 files changed, 135 insertions(+), 12 deletions(-)
 create mode 100644 test/parallel/test-repl-multiline-navigation.js

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index eec9a25fd94e1f..29e4fbb61380b3 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -454,8 +454,9 @@ class Interface extends InterfaceConstructor {
 
     // If the trimmed line is empty then return the line
     if (StringPrototypeTrim(this.line).length === 0) return this.line;
+    const normalizedLine = StringPrototypeReplaceAll(this.line, '\n', '\r');
 
-    if (this.history.length === 0 || this.history[0] !== this.line) {
+    if (this.history.length === 0 || this.history[0] !== normalizedLine) {
       if (this.removeHistoryDuplicates) {
         // Remove older history line if identical to new one
         const dupIndex = ArrayPrototypeIndexOf(this.history, this.line);
@@ -936,14 +937,17 @@ class Interface extends InterfaceConstructor {
   [kMoveDownOrHistoryNext]() {
     const { cols, rows } = this.getCursorPos();
     const splitLine = StringPrototypeSplit(this.line, '\n');
+    if (!this.historyIndex && rows === splitLine.length) {
+      return;
+    }
     // Go to the next history only if the cursor is in the first line of the multiline input.
     // Otherwise treat the "arrow down" as a movement to the next row.
     if (splitLine.length > 1 && rows < splitLine.length - 1) {
       const currentLine = splitLine[rows];
       const nextLine = splitLine[rows + 1];
       const amountToMove = (cols > nextLine.length) ?
-        +cols + nextLine.length - 1 :
-        +currentLine.length + 1;
+        currentLine.length - cols + nextLine.length + 1 :
+        currentLine.length + 1;
       // Go to the same position on the next line, or the end of the next line
       // If the current position does not exist in the next line.
       this[kMoveCursor](amountToMove);
@@ -963,9 +967,7 @@ class Interface extends InterfaceConstructor {
   [kHistoryNext]() {
     if (this.historyIndex >= 0) {
       this[kBeforeEdit](this.line, this.cursor);
-      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
-
-      const search = isLineMultiline ? '' : this[kSubstringSearch] || '';
+      const search = this[kSubstringSearch] || '';
       let index = this.historyIndex - 1;
       while (
         index >= 0 &&
@@ -987,6 +989,9 @@ class Interface extends InterfaceConstructor {
 
   [kMoveUpOrHistoryPrev]() {
     const { cols, rows } = this.getCursorPos();
+    if (this.historyIndex === this.history.length && rows) {
+      return;
+    }
     const splitLine = StringPrototypeSplit(this.line, '\n');
     // Go to the previous history only if the cursor is in the first line of the multiline input.
     // Otherwise treat the "arrow up" as a movement to the previous row.
@@ -1007,9 +1012,7 @@ class Interface extends InterfaceConstructor {
   [kHistoryPrev]() {
     if (this.historyIndex < this.history.length && this.history.length) {
       this[kBeforeEdit](this.line, this.cursor);
-      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
-
-      const search = isLineMultiline ? '' : this[kSubstringSearch] || '';
+      const search = this[kSubstringSearch] || '';
       let index = this.historyIndex + 1;
       while (
         index < this.history.length &&
@@ -1122,7 +1125,8 @@ class Interface extends InterfaceConstructor {
       !key.meta &&
       !key.shift
     ) {
-      if (this[kSubstringSearch] === null) {
+      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
+      if (this[kSubstringSearch] === null && !isLineMultiline) {
         this[kSubstringSearch] = StringPrototypeSlice(
           this.line,
           0,
diff --git a/lib/repl.js b/lib/repl.js
index 4ec7fcdd23dd6a..de64cb1fca89ff 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -966,7 +966,10 @@ function REPLServer(prompt,
         ArrayPrototypePop(lines);
         // And replace them with the single command split by '\r'
         ArrayPrototypePush(lines, cmd);
-        ArrayPrototypeUnshift(self.history, ArrayPrototypeJoin(lines, '\r'));
+        const newHistoryLine = ArrayPrototypeJoin(lines, '\r');
+        if (self.history[0] !== newHistoryLine) {
+          ArrayPrototypeUnshift(self.history, newHistoryLine);
+        }
       }
 
       if (e) {
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 1c043e5eff0adc..35a90db6c36a5d 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -767,6 +767,29 @@ const tests = [
     ],
     clean: true
   },
+  {
+    // Test that multiline history is not duplicated
+    env: { NODE_REPL_HISTORY: defaultHistoryPath },
+    skip: !process.features.inspector,
+    test: [
+      'let f = `multiline',
+      ENTER,
+      'string`',
+      ENTER,
+      UP, UP, UP,
+    ],
+    expected: [
+      prompt, ...'let f = `multiline',
+      '| ',
+      ...'string`',
+      'undefined\n',
+      prompt,
+      `${prompt}let f = \`multiline\nstring\``,
+      `${prompt}let f = \`multiline\nstring\``,
+      prompt,
+    ],
+    clean: true
+  },
 ];
 const numtests = tests.length;
 
@@ -814,7 +837,6 @@ function runTest() {
           try {
             assert.strictEqual(output, expected[i]);
           } catch (e) {
-            console.log({ output, expected: expected[i] });
             console.error(`Failed test # ${numtests - tests.length}`);
             console.error('Last outputs: ' + inspect(lastChunks, {
               breakLength: 5, colors: true
diff --git a/test/parallel/test-repl-multiline-navigation.js b/test/parallel/test-repl-multiline-navigation.js
new file mode 100644
index 00000000000000..5b617b6736f72a
--- /dev/null
+++ b/test/parallel/test-repl-multiline-navigation.js
@@ -0,0 +1,94 @@
+'use strict';
+
+// Flags: --expose-internals
+
+const common = require('../common');
+
+const assert = require('assert');
+const repl = require('internal/repl');
+const stream = require('stream');
+const fs = require('fs');
+
+class ActionStream extends stream.Stream {
+  run(data) {
+    const _iter = data[Symbol.iterator]();
+    const doAction = () => {
+      const next = _iter.next();
+      if (next.done) {
+        // Close the repl. Note that it must have a clean prompt to do so.
+        this.emit('keypress', '', { ctrl: true, name: 'd' });
+        return;
+      }
+      const action = next.value;
+
+      if (typeof action === 'object') {
+        this.emit('keypress', '', action);
+      }
+      setImmediate(doAction);
+    };
+    doAction();
+  }
+  resume() {}
+  pause() {}
+}
+ActionStream.prototype.readable = true;
+
+function cleanupTmpFile() {
+  try {
+    // Write over the file, clearing any history
+    fs.writeFileSync(defaultHistoryPath, '');
+  } catch (err) {
+    if (err.code === 'ENOENT') return true;
+    throw err;
+  }
+  return true;
+}
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+const defaultHistoryPath = tmpdir.resolve('.node_repl_history');
+
+{
+  cleanupTmpFile();
+  // It moves the cursor at the right places
+  const checkResults = common.mustSucceed((r) => {
+    r.write('let str = `');
+    r.input.run([{ name: 'enter' }]);
+    r.write('111');
+    r.input.run([{ name: 'enter' }]);
+    r.write('22222222222222');
+    r.input.run([{ name: 'enter' }]);
+    r.write('3`');
+    r.input.run([{ name: 'enter' }]);
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.cursor, 33);
+
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.cursor, 18);
+
+    r.input.run([{ name: 'right' }]);
+    r.input.run([{ name: 'right' }]);
+    r.input.run([{ name: 'right' }]);
+    r.input.run([{ name: 'right' }]);
+    r.input.run([{ name: 'right' }]);
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.cursor, 15);
+
+    r.input.run([{ name: 'down' }]);
+    assert.strictEqual(r.cursor, 19);
+  });
+
+  repl.createInternalRepl(
+    { NODE_REPL_HISTORY: defaultHistoryPath },
+    {
+      terminal: true,
+      input: new ActionStream(),
+      output: new stream.Writable({
+        write(chunk, _, next) {
+          next();
+        }
+      }),
+    },
+    checkResults
+  );
+}

From b41273af816d5274ac61c1e5cf099929b369f078 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Wed, 19 Mar 2025 11:12:24 +0100
Subject: [PATCH 06/13] repl: add pipe char for browsing multiline history

---
 lib/internal/readline/interface.js            |  48 ++++++--
 lib/internal/repl/utils.js                    |  22 ++++
 lib/repl.js                                   |   3 +
 test/parallel/test-repl-history-navigation.js |  64 +++++++---
 .../test-repl-multiline-navigation.js         | 114 +++++++++++++++++-
 5 files changed, 219 insertions(+), 32 deletions(-)

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 29e4fbb61380b3..deeca2de42527c 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -457,6 +457,12 @@ class Interface extends InterfaceConstructor {
     const normalizedLine = StringPrototypeReplaceAll(this.line, '\n', '\r');
 
     if (this.history.length === 0 || this.history[0] !== normalizedLine) {
+      if (this.lastCommandErrored && this.historyIndex === 0) {
+        // If the last command errored, remove it from history.
+        // The user is issuing a new command starting from the errored command,
+        // Hopefully with the fix
+        ArrayPrototypeShift(this.history);
+      }
       if (this.removeHistoryDuplicates) {
         // Remove older history line if identical to new one
         const dupIndex = ArrayPrototypeIndexOf(this.history, this.line);
@@ -504,8 +510,22 @@ class Interface extends InterfaceConstructor {
     // erase data
     clearScreenDown(this.output);
 
-    // Write the prompt and the current buffer content.
-    this[kWriteToOutput](line);
+    // Check if this is a multiline entry
+    const lines = StringPrototypeSplit(this.line, '\n');
+    const isMultiline = lines.length > 1;
+
+    if (!isMultiline) {
+      // Write the prompt and the current buffer content.
+      this[kWriteToOutput](line);
+    } else {
+      // Write first line with normal prompt
+      this[kWriteToOutput](this[kPrompt] + lines[0]);
+
+      // For continuation lines, add the "|" prefix
+      for (let i = 1; i < lines.length; i++) {
+        this[kWriteToOutput]('\n| ' + lines[i]);
+      }
+    }
 
     // Force terminal to allocate a new line
     if (lineCols === 0) {
@@ -945,8 +965,8 @@ class Interface extends InterfaceConstructor {
     if (splitLine.length > 1 && rows < splitLine.length - 1) {
       const currentLine = splitLine[rows];
       const nextLine = splitLine[rows + 1];
-      const amountToMove = (cols > nextLine.length) ?
-        currentLine.length - cols + nextLine.length + 1 :
+      const amountToMove = (cols > nextLine.length + 1) ?
+        currentLine.length - cols + nextLine.length + 3 :
         currentLine.length + 1;
       // Go to the same position on the next line, or the end of the next line
       // If the current position does not exist in the next line.
@@ -997,8 +1017,8 @@ class Interface extends InterfaceConstructor {
     // Otherwise treat the "arrow up" as a movement to the previous row.
     if (splitLine.length > 1 && rows > 0) {
       const previousLine = splitLine[rows - 1];
-      const amountToMove = (cols > previousLine.length) ?
-        -cols - 1 :
+      const amountToMove = (cols > previousLine.length + 1) ?
+        -cols + 1 :
         -previousLine.length - 1;
       // Go to the same position on the previous line, or the end of the previous line
       // If the current position does not exist in the previous line.
@@ -1075,9 +1095,19 @@ class Interface extends InterfaceConstructor {
    *   }}
    */
   getCursorPos() {
-    const strBeforeCursor =
-      this[kPrompt] + StringPrototypeSlice(this.line, 0, this.cursor);
-    return this[kGetDisplayPos](strBeforeCursor);
+    // Handle multiline input by accounting for "| " prefixes on continuation lines
+    const lineUptoCursor = StringPrototypeSlice(this.line, 0, this.cursor);
+    const lines = StringPrototypeSplit(lineUptoCursor, '\n');
+
+    // First line uses normal prompt, subsequent lines use "| " (2 chars)
+    let displayText = this[kPrompt] + lines[0];
+
+    // Add continuation lines with their prefixes
+    for (let i = 1; i < lines.length; i++) {
+      displayText += '\n| ' + lines[i];
+    }
+
+    return this[kGetDisplayPos](displayText);
   }
 
   // This function moves cursor dx places to the right
diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
index 126f8ae85d0977..bc768d6f454d9f 100644
--- a/lib/internal/repl/utils.js
+++ b/lib/internal/repl/utils.js
@@ -155,8 +155,15 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
   let escaped = null;
 
+  let justExecutedMultilineCommand = false;
+
   function getPreviewPos() {
     const displayPos = repl._getDisplayPos(`${repl.getPrompt()}${repl.line}`);
+    // If the line is a multi line
+    if (StringPrototypeIndexOf(repl.line, '\n') !== -1) {
+      // This is to consider the additional "| " that prefixes the line
+      displayPos.cols += 2;
+    }
     const cursorPos = repl.line.length !== repl.cursor ?
       repl.getCursorPos() :
       displayPos;
@@ -177,6 +184,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       clearLine(repl.output);
       moveCursor(repl.output, 0, -rows);
       inputPreview = null;
+      // If pressing enter on some history line,
+      // The next preview should not be generated
+      if ((key.name === 'return' || key.name === 'enter') && !key.meta && repl.historyIndex !== -1) {
+        justExecutedMultilineCommand = true;
+      }
     }
     if (completionPreview !== null) {
       // Prevent cursor moves if not necessary!
@@ -373,6 +385,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       return;
     }
 
+    if (justExecutedMultilineCommand) {
+      justExecutedMultilineCommand = false;
+      return;
+    }
+
     hasCompletions = false;
 
     // Add the autocompletion preview.
@@ -444,9 +461,14 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
       const { cursorPos, displayPos } = getPreviewPos();
       const rows = displayPos.rows - cursorPos.rows;
+      // Moves one line below all the user lines
       moveCursor(repl.output, 0, rows);
+      // Writes the preview there
       repl.output.write(`\n${result}`);
+
+      // Go back to the horizontal position of the cursor
       cursorTo(repl.output, cursorPos.cols);
+      // Go back to the vertical position of the cursor
       moveCursor(repl.output, 0, -rows - 1);
     };
 
diff --git a/lib/repl.js b/lib/repl.js
index de64cb1fca89ff..705be580b6e6a7 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -974,6 +974,9 @@ function REPLServer(prompt,
 
       if (e) {
         self._domain.emit('error', e.err || e);
+        self.lastCommandErrored = true;
+      } else {
+        self.lastCommandErrored = false;
       }
 
       // Clear buffer if no SyntaxErrors
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 35a90db6c36a5d..4325f90148eb0b 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -659,11 +659,19 @@ const tests = [
       ...'which ends here`',
       "'I am a multiline strong\\nwhich ends here'\n",
       prompt,
-      `${prompt}a = \`I am a multiline strong\nwhich ends here\``,
-      `${prompt}a = \`I am a multiline strong\nwhich ends here\``,
-      `${prompt}a = \`I am a multiline strng\nwhich ends here\``,
-      `${prompt}a = \`I am a multiline string\nwhich ends here\``,
-      `${prompt}a = \`I am a multiline string\nwhich ends here\``,
+      `${prompt}a = \`I am a multiline strong`,
+      `\n| which ends here\``,
+      `${prompt}a = \`I am a multiline strong`,
+      `\n| which ends here\``,
+
+      `${prompt}a = \`I am a multiline strng`,
+      `\n| which ends here\``,
+
+      `${prompt}a = \`I am a multiline string`,
+      `\n| which ends here\``,
+
+      `${prompt}a = \`I am a multiline string`,
+      `\n| which ends here\``,
       "'I am a multiline string\\nwhich ends here'\n",
       prompt,
     ],
@@ -707,14 +715,24 @@ const tests = [
       ...'am another one`',
       'undefined\n',
       prompt,
-      `${prompt}let c = \`I\nam another one\``,
-      `${prompt}let c = \`I\nam another one\``,
-
-      `${prompt}b = \`I am a multiline strong\nwhich ends here\``,
-      `${prompt}b = \`I am a multiline strong\nwhich ends here\``,
-      `${prompt}b = \`I am a multiline strng\nwhich ends here\``,
-      `${prompt}b = \`I am a multiline string\nwhich ends here\``,
-      `${prompt}b = \`I am a multiline string\nwhich ends here\``,
+      `${prompt}let c = \`I`,
+      `\n| am another one\``,
+
+      `${prompt}let c = \`I`,
+      `\n| am another one\``,
+
+      `${prompt}b = \`I am a multiline strong`,
+      `\n| which ends here\``,
+      `${prompt}b = \`I am a multiline strong`,
+      `\n| which ends here\``,
+      `${prompt}b = \`I am a multiline strng`,
+      `\n| which ends here\``,
+
+      `${prompt}b = \`I am a multiline string`,
+      `\n| which ends here\``,
+
+      `${prompt}b = \`I am a multiline string`,
+      `\n| which ends here\``,
       "'I am a multiline string\\nwhich ends here'\n",
       prompt,
     ],
@@ -758,10 +776,18 @@ const tests = [
       `  [message]: "Unexpected identifier 'line'"\n` +
       '}\n',
       prompt,
-      `${prompt}d = \`I am a\nsuper\nbroken\` line'`,
-      `${prompt}d = \`I am a\nsuper\nbroken\` line`,
+      `${prompt}d = \`I am a`,
+      `\n| super`,
+      `\n| broken\` line'`,
+
+      `${prompt}d = \`I am a`,
+      `\n| super`,
+      '\n| broken` line',
       '`',
-      `${prompt}d = \`I am a\nsuper\nbroken line\``,
+
+      `${prompt}d = \`I am a`,
+      `\n| super`,
+      `\n| broken line\``,
       "'I am a\\nsuper\\nbroken line'\n",
       prompt,
     ],
@@ -784,8 +810,10 @@ const tests = [
       ...'string`',
       'undefined\n',
       prompt,
-      `${prompt}let f = \`multiline\nstring\``,
-      `${prompt}let f = \`multiline\nstring\``,
+      `${prompt}let f = \`multiline`,
+      `\n| string\``,
+      `${prompt}let f = \`multiline`,
+      `\n| string\``,
       prompt,
     ],
     clean: true
diff --git a/test/parallel/test-repl-multiline-navigation.js b/test/parallel/test-repl-multiline-navigation.js
index 5b617b6736f72a..996910ce17149e 100644
--- a/test/parallel/test-repl-multiline-navigation.js
+++ b/test/parallel/test-repl-multiline-navigation.js
@@ -28,6 +28,15 @@ class ActionStream extends stream.Stream {
     };
     doAction();
   }
+  write(chunk) {
+    const chunkLines = chunk.toString('utf8').split('\n');
+    this.lines[this.lines.length - 1] += chunkLines[0];
+    if (chunkLines.length > 1) {
+      this.lines.push(...chunkLines.slice(1));
+    }
+    this.emit('line', this.lines[this.lines.length - 1]);
+    return true;
+  }
   resume() {}
   pause() {}
 }
@@ -66,12 +75,19 @@ const defaultHistoryPath = tmpdir.resolve('.node_repl_history');
     r.input.run([{ name: 'up' }]);
     assert.strictEqual(r.cursor, 18);
 
-    r.input.run([{ name: 'right' }]);
-    r.input.run([{ name: 'right' }]);
-    r.input.run([{ name: 'right' }]);
-    r.input.run([{ name: 'right' }]);
-    r.input.run([{ name: 'right' }]);
+    for (let i = 0; i < 5; i++) {
+      r.input.run([{ name: 'right' }]);
+    }
+    r.input.run([{ name: 'up' }]);
+    assert.strictEqual(r.cursor, 15);
     r.input.run([{ name: 'up' }]);
+
+    for (let i = 0; i < 5; i++) {
+      r.input.run([{ name: 'right' }]);
+    }
+    assert.strictEqual(r.cursor, 8);
+
+    r.input.run([{ name: 'down' }]);
     assert.strictEqual(r.cursor, 15);
 
     r.input.run([{ name: 'down' }]);
@@ -92,3 +108,91 @@ const defaultHistoryPath = tmpdir.resolve('.node_repl_history');
     checkResults
   );
 }
+
+{
+  cleanupTmpFile();
+  // If the last command errored and the user is trying to edit it,
+  // The errored line should be removed from history
+  const checkResults = common.mustSucceed((r) => {
+    r.write('let lineWithMistake = `I have some');
+    r.input.run([{ name: 'enter' }]);
+    r.write('problem with` my syntax\'');
+    r.input.run([{ name: 'enter' }]);
+    r.input.run([{ name: 'up' }]);
+    r.input.run([{ name: 'backspace' }]);
+    r.write('`');
+    for (let i = 0; i < 11; i++) {
+      r.input.run([{ name: 'left' }]);
+    }
+    r.input.run([{ name: 'backspace' }]);
+    r.input.run([{ name: 'enter' }]);
+
+    assert.strictEqual(r.history.length, 1);
+    assert.strictEqual(r.history[0], 'let lineWithMistake = `I have some\rproblem with my syntax`');
+    assert.strictEqual(r.line, '');
+  });
+
+  repl.createInternalRepl(
+    { NODE_REPL_HISTORY: defaultHistoryPath },
+    {
+      terminal: true,
+      input: new ActionStream(),
+      output: new stream.Writable({
+        write(chunk, _, next) {
+          next();
+        }
+      }),
+    },
+    checkResults
+  );
+}
+
+{
+  cleanupTmpFile();
+  const outputBuffer = [];
+
+  // Test that the REPL preview is properly shown on multiline commands
+  // And deleted when enter is pressed
+  const checkResults = common.mustSucceed((r) => {
+    r.write('Array(100).fill(');
+    r.input.run([{ name: 'enter' }]);
+    r.write('123');
+    r.input.run([{ name: 'enter' }]);
+    r.write(')');
+    r.input.run([{ name: 'enter' }]);
+    r.input.run([{ name: 'up' }]);
+    r.input.run([{ name: 'up' }]);
+
+    assert.deepStrictEqual(r.last, new Array(100).fill(123));
+    r.input.run([{ name: 'enter' }]);
+    assert.strictEqual(outputBuffer.includes('[\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
+    '  123\n' +
+    ']\n'), true);
+  });
+
+  repl.createInternalRepl(
+    { NODE_REPL_HISTORY: defaultHistoryPath },
+    {
+      preview: true,
+      terminal: true,
+      input: new ActionStream(),
+      output: new stream.Writable({
+        write(chunk, _, next) {
+          // Store each chunk in the buffer
+          outputBuffer.push(chunk.toString());
+          next();
+        }
+      }),
+    },
+    checkResults
+  );
+}

From eb931ad6b609db513f93b312b31611653ab6364c Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Wed, 26 Mar 2025 18:15:32 +0100
Subject: [PATCH 07/13] repl: update the cursor logic in kGetDisplayPos instead
 of getCursorPos

---
 doc/api/repl.md                               |  10 +-
 lib/internal/readline/interface.js            | 177 +++++++++++-------
 lib/internal/repl/history.js                  |   2 +-
 lib/internal/repl/utils.js                    |  11 +-
 lib/repl.js                                   |  25 ++-
 ...multiline => .node_repl_history_multiline} |   0
 test/parallel/test-repl-history-navigation.js |  60 +++---
 .../test-repl-load-multiline-from-history.js  |  40 ++--
 .../test-repl-multiline-navigation.js         |   4 +-
 9 files changed, 184 insertions(+), 145 deletions(-)
 rename test/fixtures/{.node_repl_history-multiline => .node_repl_history_multiline} (100%)

diff --git a/doc/api/repl.md b/doc/api/repl.md
index a134c493a54812..3b2f06fec780fd 100644
--- a/doc/api/repl.md
+++ b/doc/api/repl.md
@@ -605,8 +605,8 @@ The `replServer.displayPrompt()` method readies the REPL instance for input
 from the user, printing the configured `prompt` to a new line in the `output`
 and resuming the `input` to accept new input.
 
-When multi-line input is being entered, an ellipsis is printed rather than the
-'prompt'.
+When multi-line input is being entered, the "|" character is printed rather
+than the 'prompt'.
 
 When `preserveCursor` is `true`, the cursor placement will not be reset to `0`.
 
@@ -657,6 +657,12 @@ A list of the names of all Node.js modules, e.g., `'http'`.
 <!-- YAML
 added: v0.1.91
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/57400
+    description: The multi-line indicator is now "|" instead of "...".
+                 Added support for multi-line history.
+                 It is now possible to "fix" multi-line commands with syntax errors
+                 by visiting the history and editing the command.
   - version:
      - v13.4.0
      - v12.17.0
diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index deeca2de42527c..6f93944acf1033 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -24,7 +24,7 @@ const {
   SafeStringIterator,
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
-  StringPrototypeIndexOf,
+  StringPrototypeIncludes,
   StringPrototypeRepeat,
   StringPrototypeReplaceAll,
   StringPrototypeSlice,
@@ -91,6 +91,10 @@ const ESCAPE_CODE_TIMEOUT = 500;
 // Max length of the kill ring
 const kMaxLengthOfKillRing = 32;
 
+// TODO(puskin94): make this configurable
+const kMultilinePrompt = Symbol('| ');
+const kLastCommandErrored = Symbol('_lastCommandErrored');
+
 const kAddHistory = Symbol('_addHistory');
 const kBeforeEdit = Symbol('_beforeEdit');
 const kDecoder = Symbol('_decoder');
@@ -114,6 +118,7 @@ const kMoveCursor = Symbol('_moveCursor');
 const kNormalWrite = Symbol('_normalWrite');
 const kOldPrompt = Symbol('_oldPrompt');
 const kOnLine = Symbol('_onLine');
+const kSetLine = Symbol('_setLine');
 const kPreviousKey = Symbol('_previousKey');
 const kPrompt = Symbol('_prompt');
 const kPushToKillRing = Symbol('_pushToKillRing');
@@ -131,12 +136,15 @@ const kTabCompleter = Symbol('_tabCompleter');
 const kTtyWrite = Symbol('_ttyWrite');
 const kUndo = Symbol('_undo');
 const kUndoStack = Symbol('_undoStack');
+const kIsMultiline = Symbol('_isMultiline');
 const kWordLeft = Symbol('_wordLeft');
 const kWordRight = Symbol('_wordRight');
 const kWriteToOutput = Symbol('_writeToOutput');
 const kYank = Symbol('_yank');
 const kYanking = Symbol('_yanking');
 const kYankPop = Symbol('_yankPop');
+const kNormalizeHistoryLineEndings = Symbol('_normalizeHistoryLineEndings');
+const kDenormalizeHistoryLineEndings = Symbol('_denormalizeHistoryLineEndings');
 
 function InterfaceConstructor(input, output, completer, terminal) {
   this[kSawReturnAt] = 0;
@@ -217,6 +225,7 @@ function InterfaceConstructor(input, output, completer, terminal) {
   const self = this;
 
   this.line = '';
+  this[kIsMultiline] = false;
   this[kSubstringSearch] = null;
   this.output = output;
   this.input = input;
@@ -341,7 +350,7 @@ function InterfaceConstructor(input, output, completer, terminal) {
   }
 
   // Current line
-  this.line = '';
+  this[kSetLine]('');
 
   input.resume();
 }
@@ -415,6 +424,11 @@ class Interface extends InterfaceConstructor {
     }
   }
 
+  [kSetLine](line) {
+    this.line = line;
+    this[kIsMultiline] = StringPrototypeIncludes(line, '\n');
+  }
+
   [kOnLine](line) {
     if (this[kQuestionCallback]) {
       const cb = this[kQuestionCallback];
@@ -446,6 +460,16 @@ class Interface extends InterfaceConstructor {
     }
   }
 
+  // Convert newlines to a consistent format for history storage
+  [kNormalizeHistoryLineEndings](line) {
+    return StringPrototypeReplaceAll(line, '\n', '\r');
+  }
+
+  // Convert newlines back to the format expected by the UI
+  [kDenormalizeHistoryLineEndings](line) {
+    return StringPrototypeReplaceAll(line, '\r', '\n');
+  }
+
   [kAddHistory]() {
     if (this.line.length === 0) return '';
 
@@ -454,10 +478,10 @@ class Interface extends InterfaceConstructor {
 
     // If the trimmed line is empty then return the line
     if (StringPrototypeTrim(this.line).length === 0) return this.line;
-    const normalizedLine = StringPrototypeReplaceAll(this.line, '\n', '\r');
+    const normalizedLine = this[kNormalizeHistoryLineEndings](this.line);
 
     if (this.history.length === 0 || this.history[0] !== normalizedLine) {
-      if (this.lastCommandErrored && this.historyIndex === 0) {
+      if (this[kLastCommandErrored] && this.historyIndex === 0) {
         // If the last command errored, remove it from history.
         // The user is issuing a new command starting from the errored command,
         // Hopefully with the fix
@@ -510,14 +534,8 @@ class Interface extends InterfaceConstructor {
     // erase data
     clearScreenDown(this.output);
 
-    // Check if this is a multiline entry
-    const lines = StringPrototypeSplit(this.line, '\n');
-    const isMultiline = lines.length > 1;
-
-    if (!isMultiline) {
-      // Write the prompt and the current buffer content.
-      this[kWriteToOutput](line);
-    } else {
+    if (this[kIsMultiline]) {
+      const lines = StringPrototypeSplit(this.line, '\n');
       // Write first line with normal prompt
       this[kWriteToOutput](this[kPrompt] + lines[0]);
 
@@ -525,6 +543,9 @@ class Interface extends InterfaceConstructor {
       for (let i = 1; i < lines.length; i++) {
         this[kWriteToOutput]('\n| ' + lines[i]);
       }
+    } else {
+      // Write the prompt and the current buffer content.
+      this[kWriteToOutput](line);
     }
 
     // Force terminal to allocate a new line
@@ -658,7 +679,7 @@ class Interface extends InterfaceConstructor {
         this.cursor,
         this.line.length,
       );
-      this.line = beg + c + end;
+      this[kSetLine](beg + c + end);
       this.cursor += c.length;
       this[kRefreshLine]();
     } else {
@@ -706,13 +727,13 @@ class Interface extends InterfaceConstructor {
       this[kInsertString](StringPrototypeSlice(prefix, completeOn.length));
       return;
     } else if (!StringPrototypeStartsWith(completeOn, prefix)) {
-      this.line = StringPrototypeSlice(this.line,
-                                       0,
-                                       this.cursor - completeOn.length) +
+      this[kSetLine](StringPrototypeSlice(this.line,
+                                          0,
+                                          this.cursor - completeOn.length) +
                   prefix +
                   StringPrototypeSlice(this.line,
                                        this.cursor,
-                                       this.line.length);
+                                       this.line.length));
       this.cursor = this.cursor - completeOn.length + prefix.length;
       this[kRefreshLine]();
       return;
@@ -851,7 +872,7 @@ class Interface extends InterfaceConstructor {
   [kDeleteLineLeft]() {
     this[kBeforeEdit](this.line, this.cursor);
     const del = StringPrototypeSlice(this.line, 0, this.cursor);
-    this.line = StringPrototypeSlice(this.line, this.cursor);
+    this[kSetLine](StringPrototypeSlice(this.line, this.cursor));
     this.cursor = 0;
     this[kPushToKillRing](del);
     this[kRefreshLine]();
@@ -860,7 +881,7 @@ class Interface extends InterfaceConstructor {
   [kDeleteLineRight]() {
     this[kBeforeEdit](this.line, this.cursor);
     const del = StringPrototypeSlice(this.line, this.cursor);
-    this.line = StringPrototypeSlice(this.line, 0, this.cursor);
+    this[kSetLine](StringPrototypeSlice(this.line, 0, this.cursor));
     this[kPushToKillRing](del);
     this[kRefreshLine]();
   }
@@ -895,7 +916,7 @@ class Interface extends InterfaceConstructor {
             StringPrototypeSlice(this.line, 0, this.cursor - lastYank.length);
       const tail =
             StringPrototypeSlice(this.line, this.cursor);
-      this.line = head + currentYank + tail;
+      this[kSetLine](head + currentYank + tail);
       this.cursor = head.length + currentYank.length;
       this[kRefreshLine]();
     }
@@ -904,7 +925,7 @@ class Interface extends InterfaceConstructor {
   clearLine() {
     this[kMoveCursor](+Infinity);
     this[kWriteToOutput]('\r\n');
-    this.line = '';
+    this[kSetLine]('');
     this.cursor = 0;
     this.prevRows = 0;
   }
@@ -933,7 +954,7 @@ class Interface extends InterfaceConstructor {
     );
 
     const entry = ArrayPrototypePop(this[kUndoStack]);
-    this.line = entry.text;
+    this[kSetLine](entry.text);
     this.cursor = entry.cursor;
 
     this[kRefreshLine]();
@@ -948,7 +969,7 @@ class Interface extends InterfaceConstructor {
     );
 
     const entry = ArrayPrototypePop(this[kRedoStack]);
-    this.line = entry.text;
+    this[kSetLine](entry.text);
     this.cursor = entry.cursor;
 
     this[kRefreshLine]();
@@ -962,14 +983,15 @@ class Interface extends InterfaceConstructor {
     }
     // Go to the next history only if the cursor is in the first line of the multiline input.
     // Otherwise treat the "arrow down" as a movement to the next row.
-    if (splitLine.length > 1 && rows < splitLine.length - 1) {
+    if (this[kIsMultiline] && rows < splitLine.length - 1) {
       const currentLine = splitLine[rows];
       const nextLine = splitLine[rows + 1];
+      // If I am moving down and the current line is longer than the next line
       const amountToMove = (cols > nextLine.length + 1) ?
-        currentLine.length - cols + nextLine.length + 3 :
-        currentLine.length + 1;
-      // Go to the same position on the next line, or the end of the next line
-      // If the current position does not exist in the next line.
+        currentLine.length - cols + nextLine.length +
+        kMultilinePrompt.description.length + 1 : // Move to the end of the current line
+        // + chars to account for the kMultilinePrompt prefix, + 1 to go to the first char
+        currentLine.length + 1; // Otherwise just move to the next line, in the same position
       this[kMoveCursor](amountToMove);
       return;
     }
@@ -997,9 +1019,9 @@ class Interface extends InterfaceConstructor {
         index--;
       }
       if (index === -1) {
-        this.line = search;
+        this[kSetLine](search);
       } else {
-        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
+        this[kSetLine](this[kDenormalizeHistoryLineEndings](this.history[index]));
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -1012,16 +1034,15 @@ class Interface extends InterfaceConstructor {
     if (this.historyIndex === this.history.length && rows) {
       return;
     }
-    const splitLine = StringPrototypeSplit(this.line, '\n');
     // Go to the previous history only if the cursor is in the first line of the multiline input.
     // Otherwise treat the "arrow up" as a movement to the previous row.
-    if (splitLine.length > 1 && rows > 0) {
+    if (this[kIsMultiline] && rows > 0) {
+      const splitLine = StringPrototypeSplit(this.line, '\n');
       const previousLine = splitLine[rows - 1];
+      // If I am moving up and the current line is longer than the previous line
       const amountToMove = (cols > previousLine.length + 1) ?
-        -cols + 1 :
-        -previousLine.length - 1;
-      // Go to the same position on the previous line, or the end of the previous line
-      // If the current position does not exist in the previous line.
+        -cols + 1 : // Move to the beginning of the current line + 1 char to go to the end of the previous line
+        -previousLine.length - 1; // Otherwise just move to the previous line, in the same position
       this[kMoveCursor](amountToMove);
       return;
     }
@@ -1042,9 +1063,9 @@ class Interface extends InterfaceConstructor {
         index++;
       }
       if (index === this.history.length) {
-        this.line = search;
+        this[kSetLine](search);
       } else {
-        this.line = StringPrototypeReplaceAll(this.history[index], '\r', '\n');
+        this[kSetLine](this[kDenormalizeHistoryLineEndings](this.history[index]));
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -1058,31 +1079,49 @@ class Interface extends InterfaceConstructor {
     const col = this.columns;
     let rows = 0;
     str = stripVTControlCharacters(str);
-    for (const char of new SafeStringIterator(str)) {
-      if (char === '\n') {
-        // Rows must be incremented by 1 even if offset = 0 or col = +Infinity.
-        rows += MathCeil(offset / col) || 1;
-        offset = 0;
-        continue;
-      }
-      // Tabs must be aligned by an offset of the tab size.
-      if (char === '\t') {
-        offset += this.tabSize - (offset % this.tabSize);
-        continue;
+
+    // Split the string into lines for better handling of multiline scenarios
+    const lines = StringPrototypeSplit(str, '\n');
+
+    for (let i = 0; i < lines.length; i++) {
+      const line = lines[i];
+
+      // Only add prefix offset for continuation lines in user input (not prompts)
+      if (i > 0 && this[kIsMultiline]) {
+        offset += kMultilinePrompt.description.length;
       }
-      const width = getStringWidth(char, false /* stripVTControlCharacters */);
-      if (width === 0 || width === 1) {
-        offset += width;
-      } else {
-        // width === 2
-        if ((offset + 1) % col === 0) {
-          offset++;
+
+      // Process each character in the line
+      for (const char of new SafeStringIterator(line)) {
+        // Tabs must be aligned by an offset of the tab size
+        if (char === '\t') {
+          offset += this.tabSize - (offset % this.tabSize);
+          continue;
+        }
+
+        const width = getStringWidth(char, false /* stripVTControlCharacters */);
+        if (width === 0 || width === 1) {
+          offset += width;
+        } else {
+          // width === 2
+          if ((offset + 1) % col === 0) {
+            offset++;
+          }
+          offset += 2;
         }
-        offset += 2;
+      }
+
+      // Add rows for completed lines
+      if (i < lines.length - 1) {
+        // For all lines except the last one
+        rows += MathCeil(offset / col) || 1;
+        offset = 0;
       }
     }
+
     const cols = offset % col;
-    rows += (offset - cols) / col;
+    rows += MathFloor(offset / col);
+
     return { cols, rows };
   }
 
@@ -1095,19 +1134,9 @@ class Interface extends InterfaceConstructor {
    *   }}
    */
   getCursorPos() {
-    // Handle multiline input by accounting for "| " prefixes on continuation lines
-    const lineUptoCursor = StringPrototypeSlice(this.line, 0, this.cursor);
-    const lines = StringPrototypeSplit(lineUptoCursor, '\n');
-
-    // First line uses normal prompt, subsequent lines use "| " (2 chars)
-    let displayText = this[kPrompt] + lines[0];
-
-    // Add continuation lines with their prefixes
-    for (let i = 1; i < lines.length; i++) {
-      displayText += '\n| ' + lines[i];
-    }
+    const strBeforeCursor = this[kPrompt] + StringPrototypeSlice(this.line, 0, this.cursor);
 
-    return this[kGetDisplayPos](displayText);
+    return this[kGetDisplayPos](strBeforeCursor);
   }
 
   // This function moves cursor dx places to the right
@@ -1155,8 +1184,7 @@ class Interface extends InterfaceConstructor {
       !key.meta &&
       !key.shift
     ) {
-      const isLineMultiline = StringPrototypeIndexOf(this.line, '\n') !== -1;
-      if (this[kSubstringSearch] === null && !isLineMultiline) {
+      if (this[kSubstringSearch] === null && !this[kIsMultiline]) {
         this[kSubstringSearch] = StringPrototypeSlice(
           this.line,
           0,
@@ -1476,6 +1504,7 @@ module.exports = {
   kNormalWrite,
   kOldPrompt,
   kOnLine,
+  kSetLine,
   kPreviousKey,
   kPrompt,
   kQuestion,
@@ -1492,4 +1521,8 @@ module.exports = {
   kWordLeft,
   kWordRight,
   kWriteToOutput,
+  kMultilinePrompt,
+  kLastCommandErrored,
+  kNormalizeHistoryLineEndings,
+  kDenormalizeHistoryLineEndings,
 };
diff --git a/lib/internal/repl/history.js b/lib/internal/repl/history.js
index b6b596939683cd..545876185a0d3e 100644
--- a/lib/internal/repl/history.js
+++ b/lib/internal/repl/history.js
@@ -97,7 +97,7 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
-      repl.history = RegExpPrototypeSymbolSplit(/[\n]+/, data, repl.historySize);
+      repl.history = RegExpPrototypeSymbolSplit(/\n+/, data, repl.historySize);
     } else {
       repl.history = [];
     }
diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
index bc768d6f454d9f..19ac22fc9cd2f5 100644
--- a/lib/internal/repl/utils.js
+++ b/lib/internal/repl/utils.js
@@ -35,6 +35,10 @@ const {
   moveCursor,
 } = require('internal/readline/callbacks');
 
+const {
+  kSetLine,
+} = require('internal/readline/interface');
+
 const {
   commonPrefix,
   kSubstringSearch,
@@ -159,11 +163,6 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
   function getPreviewPos() {
     const displayPos = repl._getDisplayPos(`${repl.getPrompt()}${repl.line}`);
-    // If the line is a multi line
-    if (StringPrototypeIndexOf(repl.line, '\n') !== -1) {
-      // This is to consider the additional "| " that prefixes the line
-      displayPos.cols += 2;
-    }
     const cursorPos = repl.line.length !== repl.cursor ?
       repl.getCursorPos() :
       displayPos;
@@ -694,7 +693,7 @@ function setupReverseSearch(repl) {
     // line to the found entry.
     if (!isInReverseSearch) {
       if (lastMatch !== -1) {
-        repl.line = repl.history[lastMatch];
+        repl[kSetLine](repl.history[lastMatch]);
         repl.cursor = lastCursor;
         repl.historyIndex = lastMatch;
       }
diff --git a/lib/repl.js b/lib/repl.js
index 705be580b6e6a7..06b0cd4960f848 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -83,9 +83,7 @@ const {
   StringPrototypeCodePointAt,
   StringPrototypeEndsWith,
   StringPrototypeIncludes,
-  StringPrototypeIndexOf,
   StringPrototypeRepeat,
-  StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeSplit,
   StringPrototypeStartsWith,
@@ -194,6 +192,11 @@ const {
 const {
   makeContextifyScript,
 } = require('internal/vm');
+const {
+  kMultilinePrompt,
+  kLastCommandErrored,
+  kNormalizeHistoryLineEndings,
+} = require('internal/readline/interface');
 let nextREPLResourceNumber = 1;
 // This prevents v8 code cache from getting confused and using a different
 // cache from a resource of the same name
@@ -356,6 +359,7 @@ function REPLServer(prompt,
   this.editorMode = false;
   // Context id for use with the inspector protocol.
   this[kContextId] = undefined;
+  this[kLastCommandErrored] = false;
 
   if (this.breakEvalOnSigint && eval_) {
     // Allowing this would not reflect user expectations.
@@ -955,17 +959,15 @@ function REPLServer(prompt,
 
       // In the next two if blocks, we do not use os.EOL instead of '\n'
       // because on Windows it is '\r\n'
-      if (cmd && StringPrototypeIndexOf(cmd, '\n') !== -1) { // If you are editing a multiline command
-        self.history[0] = StringPrototypeReplaceAll(cmd, '\n', '\r');
+      if (StringPrototypeIncludes(cmd, '\n')) { // If you are editing a multiline command
+        self.history[0] = self[kNormalizeHistoryLineEndings](cmd, '\n', '\r');
       } else if (self[kBufferedCommandSymbol]) { // If a new multiline command was entered
         // Remove the first N lines from the self.history array
         // where N is the number of lines in the buffered command
 
         const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
         self.history = ArrayPrototypeSlice(self.history, lines.length);
-        ArrayPrototypePop(lines);
-        // And replace them with the single command split by '\r'
-        ArrayPrototypePush(lines, cmd);
+        lines[lines.length - 1] = cmd;
         const newHistoryLine = ArrayPrototypeJoin(lines, '\r');
         if (self.history[0] !== newHistoryLine) {
           ArrayPrototypeUnshift(self.history, newHistoryLine);
@@ -974,9 +976,9 @@ function REPLServer(prompt,
 
       if (e) {
         self._domain.emit('error', e.err || e);
-        self.lastCommandErrored = true;
+        self[kLastCommandErrored] = true;
       } else {
-        self.lastCommandErrored = false;
+        self[kLastCommandErrored] = false;
       }
 
       // Clear buffer if no SyntaxErrors
@@ -1216,10 +1218,7 @@ REPLServer.prototype.resetContext = function() {
 REPLServer.prototype.displayPrompt = function(preserveCursor) {
   let prompt = this._initialPrompt;
   if (this[kBufferedCommandSymbol].length) {
-    prompt = '|';
-    const len = this.lines.level.length ? this.lines.level.length - 1 : 0;
-    const levelInd = StringPrototypeRepeat('..', len);
-    prompt += levelInd + ' ';
+    prompt = kMultilinePrompt.description;
   }
 
   // Do not overwrite `_initialPrompt` here
diff --git a/test/fixtures/.node_repl_history-multiline b/test/fixtures/.node_repl_history_multiline
similarity index 100%
rename from test/fixtures/.node_repl_history-multiline
rename to test/fixtures/.node_repl_history_multiline
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 4325f90148eb0b..cb3a50a27c65dc 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -654,25 +654,25 @@ const tests = [
     expected: [
       prompt, ...'let a = ``',
       'undefined\n',
-      prompt, ...'a = `I am a multiline strong',
+      prompt, ...'a = `I am a multiline strong', // New Line, the user pressed ENTER
       '| ',
-      ...'which ends here`',
-      "'I am a multiline strong\\nwhich ends here'\n",
+      ...'which ends here`', // New Line, the user pressed ENTER
+      "'I am a multiline strong\\nwhich ends here'\n", // This is the result printed to the console
       prompt,
-      `${prompt}a = \`I am a multiline strong`,
+      `${prompt}a = \`I am a multiline strong`, // This is the history being shown and navigated
       `\n| which ends here\``,
-      `${prompt}a = \`I am a multiline strong`,
+      `${prompt}a = \`I am a multiline strong`, // This is the history being shown and navigated
       `\n| which ends here\``,
 
-      `${prompt}a = \`I am a multiline strng`,
+      `${prompt}a = \`I am a multiline strng`, // This is the history being shown and edited
       `\n| which ends here\``,
 
-      `${prompt}a = \`I am a multiline string`,
+      `${prompt}a = \`I am a multiline string`, // This is the history being shown and edited
       `\n| which ends here\``,
 
-      `${prompt}a = \`I am a multiline string`,
+      `${prompt}a = \`I am a multiline string`, // This is the history being shown and edited
       `\n| which ends here\``,
-      "'I am a multiline string\\nwhich ends here'\n",
+      "'I am a multiline string\\nwhich ends here'\n", // This is the result printed to the console
       prompt,
     ],
     clean: true
@@ -706,34 +706,34 @@ const tests = [
     expected: [
       prompt, ...'let b = ``',
       'undefined\n',
-      prompt, ...'b = `I am a multiline strong',
+      prompt, ...'b = `I am a multiline strong', // New Line, the user pressed ENTER
       '| ',
-      ...'which ends here`',
-      "'I am a multiline strong\\nwhich ends here'\n",
-      prompt, ...'let c = `I',
+      ...'which ends here`', // New Line, the user pressed ENTER
+      "'I am a multiline strong\\nwhich ends here'\n", // This is the result printed to the console
+      prompt, ...'let c = `I', // New Line, the user pressed ENTER
       '| ',
-      ...'am another one`',
+      ...'am another one`', // New Line, the user pressed ENTER
       'undefined\n',
       prompt,
-      `${prompt}let c = \`I`,
+      `${prompt}let c = \`I`, // This is the history being shown and navigated
       `\n| am another one\``,
 
-      `${prompt}let c = \`I`,
+      `${prompt}let c = \`I`, // This is the history being shown and navigated
       `\n| am another one\``,
 
-      `${prompt}b = \`I am a multiline strong`,
+      `${prompt}b = \`I am a multiline strong`, // This is the history being shown and edited
       `\n| which ends here\``,
-      `${prompt}b = \`I am a multiline strong`,
+      `${prompt}b = \`I am a multiline strong`, // This is the history being shown and edited
       `\n| which ends here\``,
-      `${prompt}b = \`I am a multiline strng`,
+      `${prompt}b = \`I am a multiline strng`, // This is the history being shown and edited
       `\n| which ends here\``,
 
-      `${prompt}b = \`I am a multiline string`,
+      `${prompt}b = \`I am a multiline string`, // This is the history being shown and edited
       `\n| which ends here\``,
 
-      `${prompt}b = \`I am a multiline string`,
+      `${prompt}b = \`I am a multiline string`, // This is the history being shown and edited
       `\n| which ends here\``,
-      "'I am a multiline string\\nwhich ends here'\n",
+      "'I am a multiline string\\nwhich ends here'\n", // This is the result printed to the console
       prompt,
     ],
     clean: true
@@ -760,13 +760,13 @@ const tests = [
       ENTER,
     ],
     expected: [
-      prompt, ...'let d = ``',
+      prompt, ...'let d = ``', // New Line, the user pressed ENTER
       'undefined\n',
-      prompt, ...'d = `I am a',
+      prompt, ...'d = `I am a', // New Line, the user pressed ENTER
       '| ',
-      ...'super',
+      ...'super', // New Line, the user pressed ENTER
       '| ',
-      ...'broken` line\'',
+      ...'broken` line\'', // New Line, the user pressed ENTER
       "[broken` line'\n" +
       '        ^^^^\n' +
       '\n' +
@@ -776,19 +776,19 @@ const tests = [
       `  [message]: "Unexpected identifier 'line'"\n` +
       '}\n',
       prompt,
-      `${prompt}d = \`I am a`,
+      `${prompt}d = \`I am a`, // This is the history being shown and edited
       `\n| super`,
       `\n| broken\` line'`,
 
-      `${prompt}d = \`I am a`,
+      `${prompt}d = \`I am a`, // This is the history being shown and edited
       `\n| super`,
       '\n| broken` line',
       '`',
 
-      `${prompt}d = \`I am a`,
+      `${prompt}d = \`I am a`, // This is the history being shown and edited
       `\n| super`,
       `\n| broken line\``,
-      "'I am a\\nsuper\\nbroken line'\n",
+      "'I am a\\nsuper\\nbroken line'\n", // This is the result printed to the console
       prompt,
     ],
     clean: true
diff --git a/test/parallel/test-repl-load-multiline-from-history.js b/test/parallel/test-repl-load-multiline-from-history.js
index 0998d664fa0bd1..5814e3819da191 100644
--- a/test/parallel/test-repl-load-multiline-from-history.js
+++ b/test/parallel/test-repl-load-multiline-from-history.js
@@ -37,47 +37,47 @@ ActionStream.prototype.readable = true;
   // Testing multiline history loading
   const tmpdir = require('../common/tmpdir');
   tmpdir.refresh();
-  const replHistoryPath = fixtures.path('.node_repl_history-multiline');
+  const replHistoryPath = fixtures.path('.node_repl_history_multiline');
 
   const checkResults = common.mustSucceed((r) => {
     assert.strictEqual(r.history.length, 4);
 
     r.input.run([{ name: 'up' }]);
-    assert.strictEqual(
-      r.line,
-      'var d = [\n' +
-    '  {\n' +
-    '    a: 1,\n' +
-    '    b: 2,\n' +
-    '  },\n' +
-    '  {\n' +
-    '    a: 3,\n' +
-    '    b: 4,\n' +
-    '    c: [{ a: 1, b: 2 },\n' +
-    '      {\n' +
-    '        a: 3,\n' +
-    '        b: 4,\n' +
-    '      }\n' +
-    '    ]\n' +
-    '  }\n' +
-    ']'
+    assert.strictEqual(r.line, 'var d = [\n' +
+      '  {\n' +
+      '    a: 1,\n' +
+      '    b: 2,\n' +
+      '  },\n' +
+      '  {\n' +
+      '    a: 3,\n' +
+      '    b: 4,\n' +
+      '    c: [{ a: 1, b: 2 },\n' +
+      '      {\n' +
+      '        a: 3,\n' +
+      '        b: 4,\n' +
+      '      }\n' +
+      '    ]\n' +
+      '  }\n' +
+      ']'
     );
 
+    // Move the cursor all lines up until the former entry is retrieved.
     for (let i = 0; i < r.line.split('\n').length; i++) {
       r.input.run([{ name: 'up' }]);
     }
     assert.strictEqual(r.line, 'const c = [\n  {\n    a: 1,\n    b: 2,\n  }\n]');
 
+    // Move the cursor all lines up until the former entry is retrieved.
     for (let i = 0; i < r.line.split('\n').length; i++) {
       r.input.run([{ name: 'up' }]);
     }
     assert.strictEqual(r.line, '`const b = [\n  1,\n  2,\n  3,\n  4,\n]`');
 
+    // Move the cursor all lines up until the former entry is retrieved.
     for (let i = 0; i < r.line.split('\n').length; i++) {
       r.input.run([{ name: 'up' }]);
     }
     assert.strictEqual(r.line, 'a = `\nI am a multiline string\nI can be as long as I want`');
-
   });
 
   repl.createInternalRepl(
diff --git a/test/parallel/test-repl-multiline-navigation.js b/test/parallel/test-repl-multiline-navigation.js
index 996910ce17149e..f8bdcc842d595e 100644
--- a/test/parallel/test-repl-multiline-navigation.js
+++ b/test/parallel/test-repl-multiline-navigation.js
@@ -59,7 +59,9 @@ const defaultHistoryPath = tmpdir.resolve('.node_repl_history');
 
 {
   cleanupTmpFile();
-  // It moves the cursor at the right places
+  // Make sure the cursor is at the right places.
+  // If the cursor is at the end of a long line and the down key is pressed,
+  // Move the cursor to the end of the next line, if shorter.
   const checkResults = common.mustSucceed((r) => {
     r.write('let str = `');
     r.input.run([{ name: 'enter' }]);

From 10af9e646f6fd690842613a26c38d7fb06e3d2b0 Mon Sep 17 00:00:00 2001
From: Ruben Bridgewater <ruben.bridgewater@datadoghq.com>
Date: Thu, 3 Apr 2025 17:50:11 +0200
Subject: [PATCH 08/13] fixup! simplify implementation

---
 doc/api/repl.md                    |  4 +--
 lib/internal/readline/interface.js | 57 ++++++++++++------------------
 lib/internal/repl/utils.js         | 23 +++++-------
 3 files changed, 33 insertions(+), 51 deletions(-)

diff --git a/doc/api/repl.md b/doc/api/repl.md
index 3b2f06fec780fd..9c9e117007ff04 100644
--- a/doc/api/repl.md
+++ b/doc/api/repl.md
@@ -605,8 +605,8 @@ The `replServer.displayPrompt()` method readies the REPL instance for input
 from the user, printing the configured `prompt` to a new line in the `output`
 and resuming the `input` to accept new input.
 
-When multi-line input is being entered, the "|" character is printed rather
-than the 'prompt'.
+When multi-line input is being entered, a pipe `'|'` is printed rather than the
+'prompt'.
 
 When `preserveCursor` is `true`, the cursor placement will not be reset to `0`.
 
diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 6f93944acf1033..70339f13129148 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -1080,47 +1080,33 @@ class Interface extends InterfaceConstructor {
     let rows = 0;
     str = stripVTControlCharacters(str);
 
-    // Split the string into lines for better handling of multiline scenarios
-    const lines = StringPrototypeSplit(str, '\n');
-
-    for (let i = 0; i < lines.length; i++) {
-      const line = lines[i];
-
-      // Only add prefix offset for continuation lines in user input (not prompts)
-      if (i > 0 && this[kIsMultiline]) {
-        offset += kMultilinePrompt.description.length;
+    for (const char of new SafeStringIterator(str)) {
+      if (char === '\n') {
+        // Rows must be incremented by 1 even if offset = 0 or col = +Infinity.
+        rows += MathCeil(offset / col) || 1;
+        // Only add prefix offset for continuation lines in user input (not prompts)
+        offset = this[kIsMultiline] ? kMultilinePrompt.description.length : 0;
+        continue;
       }
-
-      // Process each character in the line
-      for (const char of new SafeStringIterator(line)) {
-        // Tabs must be aligned by an offset of the tab size
-        if (char === '\t') {
-          offset += this.tabSize - (offset % this.tabSize);
-          continue;
-        }
-
-        const width = getStringWidth(char, false /* stripVTControlCharacters */);
-        if (width === 0 || width === 1) {
-          offset += width;
-        } else {
-          // width === 2
-          if ((offset + 1) % col === 0) {
-            offset++;
-          }
-          offset += 2;
-        }
+      // Tabs must be aligned by an offset of the tab size.
+      if (char === '\t') {
+        offset += this.tabSize - (offset % this.tabSize);
+        continue;
       }
-
-      // Add rows for completed lines
-      if (i < lines.length - 1) {
-        // For all lines except the last one
-        rows += MathCeil(offset / col) || 1;
-        offset = 0;
+      const width = getStringWidth(char, false /* stripVTControlCharacters */);
+      if (width === 0 || width === 1) {
+        offset += width;
+      } else {
+        // width === 2
+        if ((offset + 1) % col === 0) {
+          offset++;
+        }
+        offset += 2;
       }
     }
 
     const cols = offset % col;
-    rows += MathFloor(offset / col);
+    rows += (offset - cols) / col;
 
     return { cols, rows };
   }
@@ -1498,6 +1484,7 @@ module.exports = {
   kHistoryNext,
   kHistoryPrev,
   kInsertString,
+  kIsMultiline,
   kLine,
   kLine_buffer,
   kMoveCursor,
diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
index 19ac22fc9cd2f5..3ed5a26f3eb3c3 100644
--- a/lib/internal/repl/utils.js
+++ b/lib/internal/repl/utils.js
@@ -28,6 +28,10 @@ const {
   ERR_INSPECTOR_NOT_AVAILABLE,
 } = require('internal/errors').codes;
 
+const {
+  kIsMultiline,
+} = require('internal/readline/interface');
+
 const {
   clearLine,
   clearScreenDown,
@@ -159,8 +163,6 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
 
   let escaped = null;
 
-  let justExecutedMultilineCommand = false;
-
   function getPreviewPos() {
     const displayPos = repl._getDisplayPos(`${repl.getPrompt()}${repl.line}`);
     const cursorPos = repl.line.length !== repl.cursor ?
@@ -183,11 +185,6 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       clearLine(repl.output);
       moveCursor(repl.output, 0, -rows);
       inputPreview = null;
-      // If pressing enter on some history line,
-      // The next preview should not be generated
-      if ((key.name === 'return' || key.name === 'enter') && !key.meta && repl.historyIndex !== -1) {
-        justExecutedMultilineCommand = true;
-      }
     }
     if (completionPreview !== null) {
       // Prevent cursor moves if not necessary!
@@ -372,8 +369,11 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   }
 
   const showPreview = (showCompletion = true) => {
-    // Prevent duplicated previews after a refresh.
-    if (inputPreview !== null || !repl.isCompletionEnabled || !process.features.inspector) {
+    // Prevent duplicated previews after a refresh or in a multiline command.
+    if (inputPreview !== null ||
+        repl[kIsMultiline] ||
+        !repl.isCompletionEnabled ||
+        !process.features.inspector) {
       return;
     }
 
@@ -384,11 +384,6 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       return;
     }
 
-    if (justExecutedMultilineCommand) {
-      justExecutedMultilineCommand = false;
-      return;
-    }
-
     hasCompletions = false;
 
     // Add the autocompletion preview.

From c5b0df923b19c16553588c2aae2954f5c1c72fca Mon Sep 17 00:00:00 2001
From: Ruben Bridgewater <ruben.bridgewater@datadoghq.com>
Date: Thu, 3 Apr 2025 18:36:02 +0200
Subject: [PATCH 09/13] fixup! simplify code further

---
 lib/internal/readline/interface.js | 17 +++++------------
 lib/repl.js                        |  5 ++---
 2 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 70339f13129148..457dbd4876dd74 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -144,7 +144,6 @@ const kYank = Symbol('_yank');
 const kYanking = Symbol('_yanking');
 const kYankPop = Symbol('_yankPop');
 const kNormalizeHistoryLineEndings = Symbol('_normalizeHistoryLineEndings');
-const kDenormalizeHistoryLineEndings = Symbol('_denormalizeHistoryLineEndings');
 
 function InterfaceConstructor(input, output, completer, terminal) {
   this[kSawReturnAt] = 0;
@@ -461,13 +460,8 @@ class Interface extends InterfaceConstructor {
   }
 
   // Convert newlines to a consistent format for history storage
-  [kNormalizeHistoryLineEndings](line) {
-    return StringPrototypeReplaceAll(line, '\n', '\r');
-  }
-
-  // Convert newlines back to the format expected by the UI
-  [kDenormalizeHistoryLineEndings](line) {
-    return StringPrototypeReplaceAll(line, '\r', '\n');
+  [kNormalizeHistoryLineEndings](line, from, to) {
+    return StringPrototypeReplaceAll(line, from, to);
   }
 
   [kAddHistory]() {
@@ -478,7 +472,7 @@ class Interface extends InterfaceConstructor {
 
     // If the trimmed line is empty then return the line
     if (StringPrototypeTrim(this.line).length === 0) return this.line;
-    const normalizedLine = this[kNormalizeHistoryLineEndings](this.line);
+    const normalizedLine = this[kNormalizeHistoryLineEndings](this.line, '\n', '\r');
 
     if (this.history.length === 0 || this.history[0] !== normalizedLine) {
       if (this[kLastCommandErrored] && this.historyIndex === 0) {
@@ -1021,7 +1015,7 @@ class Interface extends InterfaceConstructor {
       if (index === -1) {
         this[kSetLine](search);
       } else {
-        this[kSetLine](this[kDenormalizeHistoryLineEndings](this.history[index]));
+        this[kSetLine](this[kNormalizeHistoryLineEndings](this.history[index], '\r', '\n'));
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -1065,7 +1059,7 @@ class Interface extends InterfaceConstructor {
       if (index === this.history.length) {
         this[kSetLine](search);
       } else {
-        this[kSetLine](this[kDenormalizeHistoryLineEndings](this.history[index]));
+        this[kSetLine](this[kNormalizeHistoryLineEndings](this.history[index], '\r', '\n'));
       }
       this.historyIndex = index;
       this.cursor = this.line.length; // Set cursor to end of line.
@@ -1511,5 +1505,4 @@ module.exports = {
   kMultilinePrompt,
   kLastCommandErrored,
   kNormalizeHistoryLineEndings,
-  kDenormalizeHistoryLineEndings,
 };
diff --git a/lib/repl.js b/lib/repl.js
index 06b0cd4960f848..370e611920b126 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -359,7 +359,6 @@ function REPLServer(prompt,
   this.editorMode = false;
   // Context id for use with the inspector protocol.
   this[kContextId] = undefined;
-  this[kLastCommandErrored] = false;
 
   if (this.breakEvalOnSigint && eval_) {
     // Allowing this would not reflect user expectations.
@@ -933,6 +932,8 @@ function REPLServer(prompt,
       debug('finish', e, ret);
       ReflectApply(_memory, self, [cmd]);
 
+      self[kLastCommandErrored] = false;
+
       if (e && !self[kBufferedCommandSymbol] &&
           StringPrototypeStartsWith(StringPrototypeTrim(cmd), 'npm ') &&
           !(e instanceof Recoverable)
@@ -977,8 +978,6 @@ function REPLServer(prompt,
       if (e) {
         self._domain.emit('error', e.err || e);
         self[kLastCommandErrored] = true;
-      } else {
-        self[kLastCommandErrored] = false;
       }
 
       // Clear buffer if no SyntaxErrors

From 0050358b1052e69e04f4c37981809ff6ad4a08df Mon Sep 17 00:00:00 2001
From: Ruben Bridgewater <ruben.bridgewater@datadoghq.com>
Date: Thu, 3 Apr 2025 18:39:35 +0200
Subject: [PATCH 10/13] fixup! linter

---
 lib/internal/repl/utils.js | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
index 3ed5a26f3eb3c3..b93ba335fec53a 100644
--- a/lib/internal/repl/utils.js
+++ b/lib/internal/repl/utils.js
@@ -28,10 +28,6 @@ const {
   ERR_INSPECTOR_NOT_AVAILABLE,
 } = require('internal/errors').codes;
 
-const {
-  kIsMultiline,
-} = require('internal/readline/interface');
-
 const {
   clearLine,
   clearScreenDown,
@@ -40,6 +36,7 @@ const {
 } = require('internal/readline/callbacks');
 
 const {
+  kIsMultiline,
   kSetLine,
 } = require('internal/readline/interface');
 

From 8f52797d1049232a765b686c060971f8507ef2e4 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Sat, 5 Apr 2025 23:24:58 +0200
Subject: [PATCH 11/13] repl: update to the history file, not using EOL

---
 lib/internal/readline/interface.js              |  2 +-
 lib/internal/repl/history.js                    |  2 +-
 test/parallel/test-repl-persistent-history.js   | 12 ++++--------
 test/parallel/test-repl-programmatic-history.js | 14 ++++----------
 test/parallel/test-repl-reverse-search.js       |  6 ++++--
 5 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 457dbd4876dd74..65e1b2bdf9fdd8 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -535,7 +535,7 @@ class Interface extends InterfaceConstructor {
 
       // For continuation lines, add the "|" prefix
       for (let i = 1; i < lines.length; i++) {
-        this[kWriteToOutput]('\n| ' + lines[i]);
+        this[kWriteToOutput](`\n${kMultilinePrompt.description}` + lines[i]);
       }
     } else {
       // Write the prompt and the current buffer content.
diff --git a/lib/internal/repl/history.js b/lib/internal/repl/history.js
index 545876185a0d3e..ae5015e83830a8 100644
--- a/lib/internal/repl/history.js
+++ b/lib/internal/repl/history.js
@@ -141,7 +141,7 @@ function setupHistory(repl, historyPath, ready) {
       return;
     }
     writing = true;
-    const historyData = ArrayPrototypeJoin(repl.history, os.EOL);
+    const historyData = ArrayPrototypeJoin(repl.history, '\n');
     fs.write(repl._historyHandle, historyData, 0, 'utf8', onwritten);
   }
 
diff --git a/test/parallel/test-repl-persistent-history.js b/test/parallel/test-repl-persistent-history.js
index f5e2d48139f449..2ec5a315c8a7c3 100644
--- a/test/parallel/test-repl-persistent-history.js
+++ b/test/parallel/test-repl-persistent-history.js
@@ -9,7 +9,6 @@ const REPL = require('internal/repl');
 const assert = require('assert');
 const fs = require('fs');
 const os = require('os');
-const util = require('util');
 
 if (process.env.TERM === 'dumb') {
   common.skip('skipping - dumb terminal');
@@ -41,11 +40,11 @@ class ActionStream extends stream.Stream {
       if (typeof action === 'object') {
         this.emit('keypress', '', action);
       } else {
-        this.emit('data', `${action}\n`);
+        this.emit('data', action);
       }
       setImmediate(doAction);
     };
-    setImmediate(doAction);
+    doAction();
   }
   resume() {}
   pause() {}
@@ -97,8 +96,8 @@ const tests = [
     test: [UP, '21', ENTER, "'42'", ENTER],
     expected: [
       prompt,
-      '2', '1', '21\n', prompt, prompt,
-      "'", '4', '2', "'", "'42'\n", prompt, prompt,
+      '2', '1', '21\n', prompt,
+      "'", '4', '2', "'", "'42'\n", prompt,
     ],
     clean: false
   },
@@ -195,8 +194,6 @@ function runTest(assertCleaned) {
   const opts = tests.shift();
   if (!opts) return; // All done
 
-  console.log('NEW');
-
   if (assertCleaned) {
     try {
       assert.strictEqual(fs.readFileSync(defaultHistoryPath, 'utf8'), '');
@@ -221,7 +218,6 @@ function runTest(assertCleaned) {
     output: new stream.Writable({
       write(chunk, _, next) {
         const output = chunk.toString();
-        console.log('INPUT', util.inspect(output));
 
         // Ignore escapes and blank lines
         if (output.charCodeAt(0) === 27 || /^[\r\n]+$/.test(output))
diff --git a/test/parallel/test-repl-programmatic-history.js b/test/parallel/test-repl-programmatic-history.js
index aae15eb752c862..4e8887e0e08d56 100644
--- a/test/parallel/test-repl-programmatic-history.js
+++ b/test/parallel/test-repl-programmatic-history.js
@@ -7,7 +7,6 @@ const REPL = require('repl');
 const assert = require('assert');
 const fs = require('fs');
 const os = require('os');
-const util = require('util');
 
 if (process.env.TERM === 'dumb') {
   common.skip('skipping - dumb terminal');
@@ -39,11 +38,11 @@ class ActionStream extends stream.Stream {
       if (typeof action === 'object') {
         this.emit('keypress', '', action);
       } else {
-        this.emit('data', `${action}\n`);
+        this.emit('data', action);
       }
       setImmediate(doAction);
     };
-    setImmediate(doAction);
+    doAction();
   }
   resume() {}
   pause() {}
@@ -95,10 +94,8 @@ const tests = [
     test: [UP, '21', ENTER, "'42'", ENTER],
     expected: [
       prompt,
-      // TODO(BridgeAR): The line is refreshed too many times. The double prompt
-      // is redundant and can be optimized away.
-      '2', '1', '21\n', prompt, prompt,
-      "'", '4', '2', "'", "'42'\n", prompt, prompt,
+      '2', '1', '21\n', prompt,
+      "'", '4', '2', "'", "'42'\n", prompt,
     ],
     clean: false
   },
@@ -191,8 +188,6 @@ function runTest(assertCleaned) {
   const opts = tests.shift();
   if (!opts) return; // All done
 
-  console.log('NEW');
-
   if (assertCleaned) {
     try {
       assert.strictEqual(fs.readFileSync(defaultHistoryPath, 'utf8'), '');
@@ -218,7 +213,6 @@ function runTest(assertCleaned) {
     output: new stream.Writable({
       write(chunk, _, next) {
         const output = chunk.toString();
-        console.log('INPUT', util.inspect(output));
 
         // Ignore escapes and blank lines
         if (output.charCodeAt(0) === 27 || /^[\r\n]+$/.test(output))
diff --git a/test/parallel/test-repl-reverse-search.js b/test/parallel/test-repl-reverse-search.js
index 246488cbd0ef5f..314d772adc67a5 100644
--- a/test/parallel/test-repl-reverse-search.js
+++ b/test/parallel/test-repl-reverse-search.js
@@ -28,7 +28,9 @@ class ActionStream extends stream.Stream {
       const next = _iter.next();
       if (next.done) {
         // Close the repl. Note that it must have a clean prompt to do so.
-        this.emit('keypress', '', { ctrl: true, name: 'd' });
+        setImmediate(() => {
+          this.emit('keypress', '', { ctrl: true, name: 'd' });
+        });
         return;
       }
       const action = next.value;
@@ -36,7 +38,7 @@ class ActionStream extends stream.Stream {
       if (typeof action === 'object') {
         this.emit('keypress', '', action);
       } else {
-        this.emit('data', `${action}`);
+        this.emit('data', action);
       }
       setImmediate(doAction);
     };

From 23f7e47d4417309282b8b901919d90c48d043ff4 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Tue, 8 Apr 2025 23:33:46 +0200
Subject: [PATCH 12/13] repl: use unicode chars for new lines

---
 doc/api/repl.md              | 2 ++
 lib/internal/repl/history.js | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/api/repl.md b/doc/api/repl.md
index 9c9e117007ff04..7df45684996eb2 100644
--- a/doc/api/repl.md
+++ b/doc/api/repl.md
@@ -663,6 +663,8 @@ changes:
                  Added support for multi-line history.
                  It is now possible to "fix" multi-line commands with syntax errors
                  by visiting the history and editing the command.
+                 When visiting the multiline history from an old node version,
+                 the multiline structure is not preserved.
   - version:
      - v13.4.0
      - v12.17.0
diff --git a/lib/internal/repl/history.js b/lib/internal/repl/history.js
index ae5015e83830a8..09647493895707 100644
--- a/lib/internal/repl/history.js
+++ b/lib/internal/repl/history.js
@@ -97,7 +97,7 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
-      repl.history = RegExpPrototypeSymbolSplit(/\n+/, data, repl.historySize);
+      repl.history = RegExpPrototypeSymbolSplit(/\r?\n+/, data, repl.historySize);
     } else {
       repl.history = [];
     }

From cab0f16a71996ca99fc79ba0d75acccba720bd49 Mon Sep 17 00:00:00 2001
From: Giovanni <github@puskin.it>
Date: Fri, 11 Apr 2025 10:15:11 +0200
Subject: [PATCH 13/13] repl: reverse the order of multiline histories

This will make it consistent when loading the new history format with an old node binary
---
 lib/internal/readline/interface.js         | 9 +++++++++
 lib/repl.js                                | 3 ++-
 test/fixtures/.node_repl_history_multiline | 8 ++++----
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 65e1b2bdf9fdd8..89936642356109 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -461,6 +461,15 @@ class Interface extends InterfaceConstructor {
 
   // Convert newlines to a consistent format for history storage
   [kNormalizeHistoryLineEndings](line, from, to) {
+    // Multiline history entries are saved reversed
+    if (StringPrototypeIncludes(line, '\r')) {
+      // First reverse the lines for proper order, then convert separators
+      return ArrayPrototypeJoin(
+        ArrayPrototypeReverse(StringPrototypeSplit(line, from)),
+        to,
+      );
+    }
+    // For normal cases (saving to history or non-multiline entries)
     return StringPrototypeReplaceAll(line, from, to);
   }
 
diff --git a/lib/repl.js b/lib/repl.js
index 370e611920b126..fd61add9fd25d8 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -53,6 +53,7 @@ const {
   ArrayPrototypePop,
   ArrayPrototypePush,
   ArrayPrototypePushApply,
+  ArrayPrototypeReverse,
   ArrayPrototypeShift,
   ArrayPrototypeSlice,
   ArrayPrototypeSome,
@@ -969,7 +970,7 @@ function REPLServer(prompt,
         const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
         self.history = ArrayPrototypeSlice(self.history, lines.length);
         lines[lines.length - 1] = cmd;
-        const newHistoryLine = ArrayPrototypeJoin(lines, '\r');
+        const newHistoryLine = ArrayPrototypeJoin(ArrayPrototypeReverse(lines), '\r');
         if (self.history[0] !== newHistoryLine) {
           ArrayPrototypeUnshift(self.history, newHistoryLine);
         }
diff --git a/test/fixtures/.node_repl_history_multiline b/test/fixtures/.node_repl_history_multiline
index c7e45f0154fdb4..9f1ccf5e9af3f5 100644
--- a/test/fixtures/.node_repl_history_multiline
+++ b/test/fixtures/.node_repl_history_multiline
@@ -1,4 +1,4 @@
-var d = [
  {
    a: 1,
    b: 2,
  },
  {
    a: 3,
    b: 4,
    c: [{ a: 1, b: 2 },
      {
        a: 3,
        b: 4,
      }
    ]
  }
]
-const c = [
  {
    a: 1,
    b: 2,
  }
]
-`const b = [
  1,
  2,
  3,
  4,
]`
-a = `
I am a multiline string
I can be as long as I want`
\ No newline at end of file
+]
  }
    ]
      }
        b: 4,
        a: 3,
      {
    c: [{ a: 1, b: 2 },
    b: 4,
    a: 3,
  {
  },
    b: 2,
    a: 1,
  {
var d = [
+]
  }
    b: 2,
    a: 1,
  {
const c = [
+]`
  4,
  3,
  2,
  1,
`const b = [
+I can be as long as I want`
I am a multiline string
a = `
\ No newline at end of file