fix(fetch): preserve error code in decompression pipeline for retry logic (#40946)

Author: SebTardif

packages/playwright-core/src/server/fetch.ts

@@ -482,8 +482,6 @@ export abstract class APIRequestContext extends SdkObject {
             return;
           }
         }
-        response.on('aborted', () => reject(new Error('aborted')));
-
         const chunks: Buffer[] = [];
         const notifyBodyFinished = () => {
           const body = Buffer.concat(chunks);
@@ -522,11 +520,21 @@ export abstract class APIRequestContext extends SdkObject {
           // Brotli and deflate decompressors throw if the input stream is empty.
           const emptyStreamTransform = new SafeEmptyStreamTransform(notifyBodyFinished);
           body = pipeline(response, emptyStreamTransform, transform, e => {
-            if (e)
-              reject(new Error(`failed to decompress '${encoding}' encoding: ${e.message}`));
+            if (e) {
+              if (isNetworkConnectionError(e))
+                reject(e);
+              else
+                reject(new Error(`failed to decompress '${encoding}' encoding: ${e.message}`));
+            }
+          });
+          body.on('error', e => {
+            if (isNetworkConnectionError(e))
+              reject(e);
+            else
+              reject(new Error(`failed to decompress '${encoding}' encoding: ${e}`));
           });
-          body.on('error', e => reject(new Error(`failed to decompress '${encoding}' encoding: ${e}`)));
         } else {
+          response.on('aborted', () => reject(new Error('aborted')));
           body.on('error', reject);
         }
 
@@ -804,6 +812,11 @@ function removeHeader(headers: { [name: string]: string }, name: string) {
     delete headers[existing[0]];
 }
 
+function isNetworkConnectionError(e: any): boolean {
+  const code = e?.code;
+  return code === 'ECONNRESET' || code === 'EPIPE' || code === 'ECONNABORTED';
+}
+
 function setBasicAuthorizationHeader(headers: { [name: string]: string }, credentials: HTTPCredentials) {
   const { username, password } = credentials;
   const encoded = Buffer.from(`${username || ''}:${password || ''}`).toString('base64');

tests/library/browsercontext-fetch.spec.ts

@@ -1401,3 +1401,62 @@ it('should retry on ECONNRESET', {
   expect(await response.text()).toBe('Hello!');
   expect(requestCount).toBe(4);
 });
+
+it('should retry ECONNRESET on compressed response', async ({ context, server }) => {
+  let requestCount = 0;
+  server.setRoute('/test-gzip', (req, res) => {
+    if (requestCount++ < 2) {
+      req.socket.destroy();
+      return;
+    }
+    res.writeHead(200, {
+      'Content-Encoding': 'gzip',
+      'Content-Type': 'text/plain',
+    });
+    const gzipStream = zlib.createGzip();
+    pipeline(gzipStream, res, err => {
+      if (err)
+        console.log(`Server error: ${err}`);
+    });
+    gzipStream.write('compressed-retry-ok');
+    gzipStream.end();
+  });
+  const response = await context.request.get(server.PREFIX + '/test-gzip', { maxRetries: 3 });
+  expect(response.status()).toBe(200);
+  expect(await response.text()).toBe('compressed-retry-ok');
+  expect(requestCount).toBe(3);
+});
+
+it('should retry ECONNRESET mid-stream during gzip decompression', async ({ context, server }) => {
+  let requestCount = 0;
+  server.setRoute('/test-gzip-midstream', (req, res) => {
+    requestCount++;
+    if (requestCount <= 2) {
+      // Send response headers to make client enter the decompression pipeline,
+      // then destroy the socket. This exercises the fix: without it, the
+      // pipeline error callback wraps the error, stripping .code for retry.
+      res.writeHead(200, {
+        'Content-Encoding': 'gzip',
+        'Content-Type': 'text/plain',
+      });
+      res.flushHeaders();
+      req.socket.destroy();
+      return;
+    }
+    res.writeHead(200, {
+      'Content-Encoding': 'gzip',
+      'Content-Type': 'text/plain',
+    });
+    const gzipStream = zlib.createGzip();
+    pipeline(gzipStream, res, err => {
+      if (err)
+        console.log(`Server error: ${err}`);
+    });
+    gzipStream.write('midstream-retry-ok');
+    gzipStream.end();
+  });
+  const response = await context.request.get(server.PREFIX + '/test-gzip-midstream', { maxRetries: 3 });
+  expect(response.status()).toBe(200);
+  expect(await response.text()).toBe('midstream-retry-ok');
+  expect(requestCount).toBe(3);
+});