allow sourceURL to match original implementation

nodejs · Oct 14, 2024 · ede9ffe · ede9ffe
1 parent 02f1d25
commit ede9ffe
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Showing 3 changed files with 27 additions and 6 deletions.
diff --git a/doc/api/parser.md b/doc/api/parser.md
@@ -31,7 +31,7 @@ added: REPLACEME
     * `'transform'` Strip type annotations and transform TypeScript features to JavaScript.
   * `sourceMap` {boolean} **Default:** `false`. Only when `mode` is `'transform'`, if `true`, a source map
     will be generated for the transformed code.
-  * `sourceUrl` {string}  Only when `mode` is `'transform'`, specifies the source url used in the source map.
+  * `sourceUrl` {string}  Specifies the source url used in the source map.
 * Returns: {string} The code with type annotations stripped.
   `parser.stripTypeScriptTypes()` removes type annotations from TypeScript code. It
   can be used to strip type annotations from TypeScript code before running it
@@ -42,7 +42,7 @@ added: REPLACEME
   When mode is `'transform'`, it also transforms TypeScript features to JavaScript,
   see [transform TypeScript features][] for more information.
   When mode is `'strip-only'`, source maps are not generated, because locations are preserved.
-  If `sourceMap` or `sourceUrl` is provided, when mode is `'strip-only'`, an error will be thrown.
+  If `sourceMap` is provided, when mode is `'strip-only'`, an error will be thrown.
 
 _WARNING_: The output of this function should not be considered stable across Node.js versions,
 due to changes in the TypeScript parser.
@@ -63,6 +63,24 @@ console.log(strippedCode);
 // Prints: const a         = 1;
 ```
 
+If `sourceUrl` is provided, it will be used appended as a comment at the end of the output:
+
+```mjs
+import parser from 'node:parser';
+const code = 'const a: number = 1;';
+const strippedCode = parser.stripTypeScriptTypes(code, { mode: 'strip-only', sourceUrl: 'source.ts' });
+console.log(strippedCode);
+// Prints: const a         = 1\n\n//# sourceURL=source.ts;
+```
+
+```cjs
+const parser = require('node:parser');
+const code = 'const a: number = 1;';
+const strippedCode = parser.stripTypeScriptTypes(code, { mode: 'strip-only', sourceUrl: 'source.ts' });
+console.log(strippedCode);
+// Prints: const a         = 1\n\n//# sourceURL=source.ts;
+```
+
 When `mode` is `'transform'`, the code is transformed to JavaScript:
 
 ```mjs

diff --git a/lib/internal/parser/typescript.js b/lib/internal/parser/typescript.js
@@ -66,7 +66,6 @@ function stripTypeScriptTypes(code, options = kEmptyObject) {
   validateOneOf(mode, 'options.mode', ['strip-only', 'transform']);
   if (mode === 'strip-only') {
     validateOneOf(sourceMap, 'options.sourceMap', [false, undefined]);
-    validateOneOf(sourceUrl, 'options.sourceUrl', ['', undefined]);
   }
   validateBoolean(sourceMap, 'options.sourceMap');
   validateString(sourceUrl, 'options.sourceUrl');
@@ -82,6 +81,11 @@ function stripTypeScriptTypes(code, options = kEmptyObject) {
   if (map) {
     return addSourceMap(transformed, map);
   }
+
+  if (sourceUrl) {
+    return `${transformed}\n\n//# sourceURL=${sourceUrl}`;
+  }
+
   return transformed;
 }
 

diff --git a/test/parallel/test-parser-strip-types.js b/test/parallel/test-parser-strip-types.js
@@ -43,9 +43,8 @@ test('stripTypeScriptTypes sourceMap throws when mode is strip-only', () => {
 
 test('stripTypeScriptTypes sourceUrl throws when mode is strip-only', () => {
   const source = 'const x: number = 1;';
-  assert.throws(() => stripTypeScriptTypes(source,
-                                           { mode: 'strip-only', sourceUrl: 'foo.ts' }),
-                { code: 'ERR_INVALID_ARG_VALUE' });
+  const result = stripTypeScriptTypes(source, { mode: 'strip-only', sourceUrl: 'foo.ts' });
+  assert.strictEqual(result, 'const x         = 1;\n\n//# sourceURL=foo.ts');
 });
 
 test('stripTypeScriptTypes source map when mode is transform', () => {