stream: fix brotli error handling in web compression streams

Convert brotli decompression errors to TypeError to match the
Compression Streams spec, by extending handleKnownInternalErrors()
in the adapters layer to recognize brotli error codes.

This replaces the manual error event handler on DecompressionStream
which was redundant with the adapter's built-in error propagation.

Author: panva

lib/internal/webstreams/adapters.js

@@ -11,6 +11,7 @@ const {
   SafePromiseAll,
   SafePromisePrototypeFinally,
   SafeSet,
+  StringPrototypeStartsWith,
   TypeError,
   TypedArrayPrototypeGetBuffer,
   TypedArrayPrototypeGetByteLength,
@@ -115,7 +116,14 @@ function handleKnownInternalErrors(cause) {
     case cause?.code === 'ERR_STREAM_PREMATURE_CLOSE': {
       return new AbortError(undefined, { cause });
     }
-    case ZLIB_FAILURES.has(cause?.code): {
+    case ZLIB_FAILURES.has(cause?.code):
+    // Brotli decoder error codes are formatted as 'ERR_' +
+    // BrotliDecoderErrorString(), where the latter returns strings like
+    // '_ERROR_FORMAT_...', '_ERROR_ALLOC_...', '_ERROR_UNREACHABLE', etc.
+    // The resulting JS error codes all start with 'ERR__ERROR_'.
+    // Falls through
+    case cause?.code != null &&
+      StringPrototypeStartsWith(cause.code, 'ERR__ERROR_'): {
       // eslint-disable-next-line no-restricted-syntax
       const error = new TypeError(undefined, { cause });
       error.code = cause.code;

lib/internal/webstreams/compression.js

@@ -157,14 +157,6 @@ class DecompressionStream {
     }
     addBufferSourceValidation(this.#handle);
     this.#transform = newReadableWritablePairFromDuplex(this.#handle);
-
-    this.#handle.on('error', (err) => {
-      if (this.#transform?.writable &&
-        !this.#transform.writable.locked &&
-        typeof this.#transform.writable.abort === 'function') {
-        this.#transform.writable.abort(err);
-      }
-    });
   }
 
   /**

test/parallel/test-webstreams-compression-bad-chunks.js

@@ -55,3 +55,22 @@ for (const format of ['deflate', 'deflate-raw', 'gzip', 'brotli']) {
     });
   }
 }
+
+// Verify that decompression errors (e.g. corrupt data) are surfaced as
+// TypeError, not plain Error, per the Compression Streams spec.
+for (const format of ['deflate', 'deflate-raw', 'gzip', 'brotli']) {
+  test(`DecompressionStream surfaces corrupt data as TypeError for ${format}`, async () => {
+    const ds = new DecompressionStream(format);
+    const writer = ds.writable.getWriter();
+    const reader = ds.readable.getReader();
+
+    // Write invalid bytes for any format — these are not valid compressed data.
+    const corruptData = new Uint8Array([0, 1, 2, 3, 4, 5]);
+
+    writer.write(corruptData).then(() => {}, () => {});
+    reader.read().then(() => {}, () => {});
+
+    await assert.rejects(writer.close(), { name: 'TypeError' });
+    await assert.rejects(reader.closed, { name: 'TypeError' });
+  });
+}

test/wpt/status/compression.json

@@ -1,12 +1,4 @@
 {
-  "decompression-bad-chunks.any.js": {
-    "fail": {
-      "expected": [
-        "chunk of type invalid deflate bytes should error the stream for brotli",
-        "chunk of type invalid gzip bytes should error the stream for brotli"
-      ]
-    }
-  },
   "compression-with-detach.window.js": {
     "requires": ["crypto"]
   },