[v12.x backport] module: improve support of data: URLs

lib/internal/modules/esm/get_source.js

@@ -1,5 +1,8 @@
 'use strict';
 
+const {
+  decodeURIComponent,
+} = primordials;
 const { getOptionValue } = require('internal/options');
 const manifest = getOptionValue('--experimental-policy') ?
   require('internal/process/policy').manifest :
@@ -28,8 +31,8 @@ async function defaultGetSource(url, { format } = {}, defaultGetSource) {
     if (!match) {
       throw new ERR_INVALID_URL(url);
     }
-    const [ , base64, body ] = match;
-    source = Buffer.from(body, base64 ? 'base64' : 'utf8');
+    const { 1: base64, 2: body } = match;
+    source = Buffer.from(decodeURIComponent(body), base64 ? 'base64' : 'utf8');
   } else {
     throw new ERR_INVALID_URL_SCHEME(['file', 'data']);
   }

lib/internal/per_context/primordials.js

@@ -106,6 +106,16 @@ primordials.SafePromise = makeSafe(
   class SafePromise extends Promise {}
 );
 
+// Create copies of URI handling functions
+[
+  decodeURI,
+  decodeURIComponent,
+  encodeURI,
+  encodeURIComponent,
+].forEach((fn) => {
+  primordials[fn.name] = fn;
+});
+
 // Create copies of the namespace objects
 [
   'JSON',

lib/internal/url.js

@@ -14,6 +14,7 @@ const {
   Symbol,
   SymbolIterator,
   SymbolToStringTag,
+  decodeURIComponent,
 } = primordials;
 
 const { inspect } = require('internal/util/inspect');

lib/querystring.js

@@ -29,6 +29,7 @@ const {
   MathAbs,
   ObjectCreate,
   ObjectKeys,
+  decodeURIComponent,
 } = primordials;
 
 const { Buffer } = require('buffer');

lib/url.js

@@ -25,6 +25,7 @@ const {
   ObjectCreate,
   ObjectKeys,
   SafeSet,
+  decodeURIComponent,
 } = primordials;
 
 const { toASCII } = require('internal/idna');

test/es-module/test-esm-data-urls.js

@@ -102,4 +102,9 @@ function createBase64URL(mime, body) {
       assert.strictEqual(e.code, 'ERR_INVALID_RETURN_PROPERTY_VALUE');
     }
   }
+  {
+    const plainESMURL = 'data:text/javascript,export%20default%202';
+    const module = await import(plainESMURL);
+    assert.strictEqual(module.default, 2);
+  }
 })().then(common.mustCall());