buffer: normalize lone "\r" in Blob native line endings

watilde · aduh95 · commit d1567abe3ecf · 2026-07-21T19:01:03.000+02:00
`new Blob(parts, { endings: 'native' })` failed to normalize a standalone carriage return. The replacement regex only matched `\n` and `\r\n`, so a lone `\r` (and runs such as `\r\r`) were left untouched instead of being converted to the platform's native line ending. The WHATWG "convert line endings to native" algorithm requires `\r`, `\n`, and `\r\n` to all be normalized. Match `\r\n` before a lone `\r` so that CRLF collapses to a single native ending. Refs: https://w3c.github.io/FileAPI/#convert-line-endings-to-native Signed-off-by: Daijiro Wachi <daijiro.wachi@gmail.com> PR-URL: #64115 Refs: https://w3c.github.io/FileAPI/#convert-line-endings-to-native Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Jason Zhang <xzha4350@gmail.com>
diff --git a/lib/internal/blob.js b/lib/internal/blob.js
@@ -122,7 +122,7 @@ function getSource(source, endings) {
     source = new Uint8Array(source);
   } else if (!isArrayBufferView(source)) {
     if (endings === 'native')
-      source = RegExpPrototypeSymbolReplace(/\n|\r\n/g, source, EOL);
+      source = RegExpPrototypeSymbolReplace(/\r\n|\r|\n/g, source, EOL);
     source = enc.encode(source);
   }
 
diff --git a/test/parallel/test-blob.js b/test/parallel/test-blob.js
@@ -407,6 +407,24 @@ assert.throws(() => new Blob({}), {
   const b = new Blob(['hello\n'], { endings: 'native' });
   assert.strictEqual(b.size, EOL.length + 5);
 
+  // The WHATWG "convert line endings to native" algorithm normalizes every
+  // standalone "\r", "\n", and "\r\n" sequence to the native line ending.
+  // Refs: https://w3c.github.io/FileAPI/#convert-line-endings-to-native
+  (async () => {
+    const cases = [
+      ['a\rb', `a${EOL}b`],
+      ['a\nb', `a${EOL}b`],
+      ['a\r\nb', `a${EOL}b`],
+      ['a\r\rb', `a${EOL}${EOL}b`],
+      ['a\n\rb', `a${EOL}${EOL}b`],
+      ['\r\n\r', `${EOL}${EOL}`],
+    ];
+    for (const [input, expected] of cases) {
+      const blob = new Blob([input], { endings: 'native' });
+      assert.strictEqual(await blob.text(), expected);
+    }
+  })().then(common.mustCall());
+
   [1, {}, 'foo'].forEach((endings) => {
     assert.throws(() => new Blob([], { endings }), {
       code: 'ERR_INVALID_ARG_VALUE',

Original file line number	Diff line number	Diff line change
`@@ -122,7 +122,7 @@ function getSource(source, endings) {`
`122`	`122`	`source = new Uint8Array(source);`
`123`	`123`	`} else if (!isArrayBufferView(source)) {`
`124`	`124`	`if (endings === 'native')`
`125`		`- source = RegExpPrototypeSymbolReplace(/\n\|\r\n/g, source, EOL);`
	`125`	`+ source = RegExpPrototypeSymbolReplace(/\r\n\|\r\|\n/g, source, EOL);`
`126`	`126`	`source = enc.encode(source);`
`127`	`127`	`}`
`128`	`128`