perf(ui): optimize stripUnsafeCharacters with regex

packages/cli/src/ui/utils/textUtils.test.ts

@@ -58,9 +58,289 @@ describe('textUtils', () => {
   });
 
   describe('stripUnsafeCharacters', () => {
-    it('should not strip tab characters', () => {
-      const input = 'hello	world';
-      expect(stripUnsafeCharacters(input)).toBe('hello	world');
+    describe('preserved characters', () => {
+      it('should preserve TAB (0x09)', () => {
+        const input = 'hello\tworld';
+        expect(stripUnsafeCharacters(input)).toBe('hello\tworld');
+      });
+
+      it('should preserve LF/newline (0x0A)', () => {
+        const input = 'hello\nworld';
+        expect(stripUnsafeCharacters(input)).toBe('hello\nworld');
+      });
+
+      it('should preserve CR (0x0D)', () => {
+        const input = 'hello\rworld';
+        expect(stripUnsafeCharacters(input)).toBe('hello\rworld');
+      });
+
+      it('should preserve CRLF (0x0D 0x0A)', () => {
+        const input = 'hello\r\nworld';
+        expect(stripUnsafeCharacters(input)).toBe('hello\r\nworld');
+      });
+
+      it('should preserve DEL (0x7F)', () => {
+        const input = 'hello\x7Fworld';
+        expect(stripUnsafeCharacters(input)).toBe('hello\x7Fworld');
+      });
+
+      it('should preserve all printable ASCII (0x20-0x7E)', () => {
+        const printableAscii =
+          ' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~';
+        expect(stripUnsafeCharacters(printableAscii)).toBe(printableAscii);
+      });
+
+      it('should preserve Unicode characters above 0x9F', () => {
+        const input = 'Hello κόσμε 世界 🌍';
+        expect(stripUnsafeCharacters(input)).toBe('Hello κόσμε 世界 🌍');
+      });
+
+      it('should preserve emojis', () => {
+        const input = '🎉 Celebration! 🚀 Launch! 💯';
+        expect(stripUnsafeCharacters(input)).toBe(
+          '🎉 Celebration! 🚀 Launch! 💯',
+        );
+      });
+
+      it('should preserve complex emoji sequences (ZWJ)', () => {
+        const input = 'Family: 👨‍👩‍👧‍👦 Flag: 🏳️‍🌈';
+        expect(stripUnsafeCharacters(input)).toBe('Family: 👨‍👩‍👧‍👦 Flag: 🏳️‍🌈');
+      });
+    });
+
+    describe('stripped C0 control characters (0x00-0x1F except TAB/LF/CR)', () => {
+      it('should strip NULL (0x00)', () => {
+        const input = 'hello\x00world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip SOH (0x01)', () => {
+        const input = 'hello\x01world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip STX (0x02)', () => {
+        const input = 'hello\x02world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip ETX (0x03)', () => {
+        const input = 'hello\x03world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip EOT (0x04)', () => {
+        const input = 'hello\x04world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip ENQ (0x05)', () => {
+        const input = 'hello\x05world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip ACK (0x06)', () => {
+        const input = 'hello\x06world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip BELL (0x07)', () => {
+        const input = 'hello\x07world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip BACKSPACE (0x08)', () => {
+        const input = 'hello\x08world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip VT/Vertical Tab (0x0B)', () => {
+        const input = 'hello\x0Bworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip FF/Form Feed (0x0C)', () => {
+        const input = 'hello\x0Cworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip SO (0x0E)', () => {
+        const input = 'hello\x0Eworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip SI (0x0F)', () => {
+        const input = 'hello\x0Fworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip DLE (0x10)', () => {
+        const input = 'hello\x10world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip DC1 (0x11)', () => {
+        const input = 'hello\x11world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip DC2 (0x12)', () => {
+        const input = 'hello\x12world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip DC3 (0x13)', () => {
+        const input = 'hello\x13world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip DC4 (0x14)', () => {
+        const input = 'hello\x14world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip NAK (0x15)', () => {
+        const input = 'hello\x15world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip SYN (0x16)', () => {
+        const input = 'hello\x16world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip ETB (0x17)', () => {
+        const input = 'hello\x17world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip CAN (0x18)', () => {
+        const input = 'hello\x18world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip EM (0x19)', () => {
+        const input = 'hello\x19world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip SUB (0x1A)', () => {
+        const input = 'hello\x1Aworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip FS (0x1C)', () => {
+        const input = 'hello\x1Cworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip GS (0x1D)', () => {
+        const input = 'hello\x1Dworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip RS (0x1E)', () => {
+        const input = 'hello\x1Eworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip US (0x1F)', () => {
+        const input = 'hello\x1Fworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+    });
+
+    describe('stripped C1 control characters (0x80-0x9F)', () => {
+      it('should strip all C1 control characters', () => {
+        // Test a few representative C1 control chars
+        expect(stripUnsafeCharacters('hello\x80world')).toBe('helloworld');
+        expect(stripUnsafeCharacters('hello\x85world')).toBe('helloworld'); // NEL
+        expect(stripUnsafeCharacters('hello\x8Aworld')).toBe('helloworld');
+        expect(stripUnsafeCharacters('hello\x90world')).toBe('helloworld');
+        expect(stripUnsafeCharacters('hello\x9Fworld')).toBe('helloworld');
+      });
+
+      it('should preserve characters at 0xA0 and above (non-C1)', () => {
+        // 0xA0 is non-breaking space, should be preserved
+        expect(stripUnsafeCharacters('hello\xA0world')).toBe('hello\xA0world');
+      });
+    });
+
+    describe('ANSI escape sequence stripping', () => {
+      it('should strip ANSI color codes', () => {
+        const input = '\x1b[31mRed\x1b[0m text';
+        expect(stripUnsafeCharacters(input)).toBe('Red text');
+      });
+
+      it('should strip ANSI cursor movement codes', () => {
+        const input = 'hello\x1b[9D\x1b[Kworld';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should strip complex ANSI sequences', () => {
+        const input = '\x1b[1;32;40mBold Green on Black\x1b[0m';
+        expect(stripUnsafeCharacters(input)).toBe('Bold Green on Black');
+      });
+    });
+
+    describe('multiple control characters', () => {
+      it('should strip multiple different control characters', () => {
+        const input = 'a\x00b\x01c\x02d\x07e\x08f';
+        expect(stripUnsafeCharacters(input)).toBe('abcdef');
+      });
+
+      it('should handle consecutive control characters', () => {
+        const input = 'hello\x00\x01\x02\x03\x04world';
+        expect(stripUnsafeCharacters(input)).toBe('helloworld');
+      });
+
+      it('should handle mixed preserved and stripped chars', () => {
+        const input = 'line1\n\x00line2\t\x07line3\r\n';
+        expect(stripUnsafeCharacters(input)).toBe('line1\nline2\tline3\r\n');
+      });
+    });
+
+    describe('edge cases', () => {
+      it('should handle empty string', () => {
+        expect(stripUnsafeCharacters('')).toBe('');
+      });
+
+      it('should handle string with only control characters', () => {
+        expect(stripUnsafeCharacters('\x00\x01\x02\x03')).toBe('');
+      });
+
+      it('should handle string with only preserved whitespace', () => {
+        expect(stripUnsafeCharacters('\t\n\r')).toBe('\t\n\r');
+      });
+
+      it('should handle very long strings efficiently', () => {
+        const longString = 'a'.repeat(10000) + '\x00' + 'b'.repeat(10000);
+        const result = stripUnsafeCharacters(longString);
+        expect(result).toBe('a'.repeat(10000) + 'b'.repeat(10000));
+        expect(result.length).toBe(20000);
+      });
+
+      it('should handle surrogate pairs correctly', () => {
+        // 𝌆 is outside BMP (U+1D306)
+        const input = '𝌆hello𝌆';
+        expect(stripUnsafeCharacters(input)).toBe('𝌆hello𝌆');
+      });
+
+      it('should handle mixed BMP and non-BMP characters', () => {
+        const input = 'Hello 世界 🌍 привет';
+        expect(stripUnsafeCharacters(input)).toBe('Hello 世界 🌍 привет');
+      });
+    });
+
+    describe('performance: regex vs array-based', () => {
+      it('should handle real-world terminal output with control chars', () => {
+        // Simulate terminal output with various control sequences
+        const terminalOutput =
+          '\x1b[32mSuccess:\x1b[0m File saved\x07\n\x1b[?25hDone';
+        expect(stripUnsafeCharacters(terminalOutput)).toBe(
+          'Success: File saved\nDone',
+        );
+      });
     });
   });
   describe('escapeAnsiCtrlCodes', () => {

packages/cli/src/ui/utils/textUtils.ts

@@ -104,7 +104,7 @@ export function cpSlice(str: string, start: number, end?: number): string {
  * Characters stripped:
  * - ANSI escape sequences (via strip-ansi)
  * - VT control sequences (via Node.js util.stripVTControlCharacters)
- * - C0 control chars (0x00-0x1F) except CR/LF which are handled elsewhere
+ * - C0 control chars (0x00-0x1F) except TAB(0x09), LF(0x0A), CR(0x0D)
  * - C1 control chars (0x80-0x9F) that can cause display issues
  *
  * Characters preserved:
@@ -117,28 +117,11 @@ export function stripUnsafeCharacters(str: string): string {
   const strippedAnsi = stripAnsi(str);
   const strippedVT = stripVTControlCharacters(strippedAnsi);
 
-  return toCodePoints(strippedVT)
-    .filter((char) => {
-      const code = char.codePointAt(0);
-      if (code === undefined) return false;
-
-      // Preserve CR/LF/TAB for line handling
-      if (code === 0x0a || code === 0x0d || code === 0x09) return true;
-
-      // Remove C0 control chars (except CR/LF) that can break display
-      // Examples: BELL(0x07) makes noise, BS(0x08) moves cursor, VT(0x0B), FF(0x0C)
-      if (code >= 0x00 && code <= 0x1f) return false;
-
-      // Remove C1 control chars (0x80-0x9f) - legacy 8-bit control codes
-      if (code >= 0x80 && code <= 0x9f) return false;
-
-      // Preserve DEL (0x7f) - it's handled functionally by applyOperations as backspace
-      // and doesn't cause rendering issues when displayed
-
-      // Preserve all other characters including Unicode/emojis
-      return true;
-    })
-    .join('');
+  // Use a regex to strip remaining unsafe control characters
+  // C0: 0x00-0x1F except 0x09 (TAB), 0x0A (LF), 0x0D (CR)
+  // C1: 0x80-0x9F
+  // eslint-disable-next-line no-control-regex
+  return strippedVT.replace(/[\x00-\x08\x0B\x0C\x0E-\x1F\x80-\x9F]/g, '');
 }
 
 /**