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@Drejerdk Drejerdk commented Dec 31, 2025

WebSocket upgrade/unexpected-response Events

Implements support for upgrade and unexpected-response events in the ws package by exposing the HTTP upgrade status code from Bun's native WebSocket.

Implementation

Native WebSocket Changes

Added a upgradeStatusCode property to the native WebSocket that stores the HTTP status code (101) from the upgrade handshake.

Why add this property?

The ws package needs real HTTP response data to properly implement the upgrade event. Without access to the actual status code, we can only provide a hardcoded mock value. By exposing upgradeStatusCode on the native WebSocket, the ws.js wrapper can read the real value and emit accurate upgrade events.

I believe this is acceptable to add given that Bun's WebSocket already has non-standard extensions like ping(), pong(), and terminate() methods. This property follows the same pattern - it's read-only, doesn't interfere with standard behavior, and provides useful functionality.

The status code is:

  1. Captured in WebSocketUpgradeClient from the HTTP response
  2. Passed by value (u16) through the Zig/C++ boundary
  3. Stored in the WebSocket object as m_upgradeStatusCode
  4. Exposed to JavaScript as a read-only property
  5. Added to TypeScript definitions for type checking

The ws package now reads this property and emits the upgrade event with the real status code. The unexpected-response event continues to emit mock data (as before), triggered on connection errors.

What This Provides

  • Real HTTP status code (101 for successful upgrades)
  • Removes Playwright warnings about unimplemented events
  • Compatible with Bruno, Postman, and other WebSocket tools
  • No memory management overhead (status code passed by value)

Headers are still empty but can be added in the future if needed.

Testing

All tests pass in test/regression/issue/05951.test.ts:

bun bd test test/regression/issue/05951.test.ts

ws WebSocket should handle 'upgrade' event listener without warning
ws WebSocket should handle 'unexpected-response' event listener without warning
ws WebSocket with successful connection should emit upgrade event
ws WebSocket upgrade event should provide response object
ws WebSocket should work without upgrade listener (backward compatibility)
native WebSocket should expose upgradeStatusCode property

Also verified existing WebSocket tests still pass:

  • test/js/first_party/ws/ws.test.ts - 41 tests pass
  • test/js/web/websocket/websocket-client.test.ts - 29 tests pass

Fixes #5951

@Drejerdk Drejerdk requested a review from alii as a code owner December 31, 2025 00:02
Adds upgradeStatusCode property to native WebSocket to expose the HTTP
status code from the upgrade handshake. The ws package uses this to emit
the upgrade event with real status code data instead of hardcoded 101.

This removes Playwright warnings about unimplemented upgrade and
unexpected-response events.

Fixes oven-sh#5951
@Drejerdk Drejerdk force-pushed the claude/fix-ws-upgrade-unexpected-response-events-5951 branch from fe79358 to 61c85b5 Compare December 31, 2025 00:05
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Reviewing files that changed from the base of the PR and between 8909e0f and 4544cc4.

📒 Files selected for processing (1)
  • test/regression/issue/05951.test.ts

Walkthrough

Expose the HTTP upgrade status code on WebSocket via a new readonly upgradeStatusCode property; propagate the status code through Zig and C++ layers; register a JS getter on the WebSocket prototype; update the ws wrapper to emit upgrade and unexpected-response events; add tests validating behavior and warnings.

Changes

Cohort / File(s) Summary
Type definitions
packages/bun-types/bun.d.ts
Added readonly upgradeStatusCode: number to the WebSocket interface with JSDoc.
JS WebSocket wrapper
src/js/thirdparty/ws.js
Emit upgrade event with a response-like object (statusCode, statusMessage, headers); add unexpected-response handling; narrow prior warning logic to only redirect.
C++ WebSocket bindings & JS prototype
src/bun.js/bindings/webcore/WebSocket.h, src/bun.js/bindings/webcore/WebSocket.cpp, src/bun.js/bindings/webcore/JSWebSocket.cpp
Added m_upgradeStatusCode (uint16_t) and upgradeStatusCode() accessor; updated didConnect and WebSocket__didConnect signatures to accept the status code; added a read-only upgradeStatusCode getter on the JS prototype.
Zig websocket client layers
src/http/websocket_client/CppWebSocket.zig, src/http/websocket_client/WebSocketUpgradeClient.zig
Updated didConnect and extern WebSocket__didConnect signatures to accept upgrade_status_code/upgradeStatusCode and forwarded the status code at call sites.
Tests
test/regression/issue/05951.test.ts
Added tests verifying upgrade and unexpected-response events, sequencing (upgrade before open), response object shape (statusCode, statusMessage, headers), absence of prior warnings, and upgradeStatusCode presence/type on native WebSocket.

Suggested reviewers

  • Jarred-Sumner
  • cirospaciari
  • zackradisic

Pre-merge checks

✅ Passed checks (4 passed)
Check name Status Explanation
Title check ✅ Passed The title clearly and concisely summarizes the main change: implementing upgrade and unexpected-response events for ws WebSocket handling.
Description check ✅ Passed The PR description comprehensively covers the implementation, includes a detailed explanation of why the change was made, testing results, and addresses the linked issue.
Linked Issues check ✅ Passed The PR successfully implements support for 'upgrade' and 'unexpected-response' events [#5951] by exposing upgradeStatusCode and modifying ws.js event handling to emit proper upgrade events without warnings.
Out of Scope Changes check ✅ Passed All changes are directly related to implementing upgrade and unexpected-response events. No unrelated modifications detected in the WebSocket type definitions, native bindings, wrapper layer, or tests.

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📒 Files selected for processing (8)
  • packages/bun-types/bun.d.ts
  • src/bun.js/bindings/webcore/JSWebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.h
  • src/http/websocket_client/CppWebSocket.zig
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  • src/js/thirdparty/ws.js
  • test/regression/issue/05951.test.ts
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test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}

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test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}: Use bun:test with files that end in *.test.{ts,js,jsx,tsx,mjs,cjs}
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Always use await using or using to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc
Always check exit codes and test error scenarios in error tests
Use describe.each() for parameterized tests
Use toMatchSnapshot() for snapshot testing
Use beforeAll(), afterEach(), beforeEach() for setup/teardown in tests
Track resources (servers, clients) in arrays for cleanup in afterEach()

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test/regression/issue/**/*.test.ts

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Regression tests for specific issues go in /test/regression/issue/${issueNumber}.test.ts. Do not put tests without issue numbers in the regression directory

Files:

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**/*.test.ts?(x)

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For multi-file tests, prefer tempDir and Bun.spawn over single-file tests
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Verify tests fail with USE_SYSTEM_BUN=1 bun test <file> and pass with bun bd test <file> - tests are invalid if they pass with USE_SYSTEM_BUN=1
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Files:

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test/regression/issue/*.test.ts

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Place regression tests for specific GitHub issues in test/regression/issue/${issueNumber}.test.ts with real issue numbers only

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Files:

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src/bun.js/bindings/**/*.cpp: Create classes in three parts in C++ when there is a public constructor: Foo (JSDestructibleObject), FooPrototype (JSNonFinalObject), and FooConstructor (InternalFunction)
Define properties using HashTableValue arrays in C++ JavaScript class bindings
Add iso subspaces for C++ classes with fields in JavaScript class bindings
Cache structures in ZigGlobalObject for JavaScript class bindings

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  • src/bun.js/bindings/webcore/WebSocket.cpp
src/**/*.zig

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src/**/*.zig: Private fields in Zig are fully supported using the # prefix: struct { #foo: u32 };
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Prefer @import at the bottom of the file (auto formatter will move them automatically)

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🧠 Learnings (28)
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add corresponding test cases to test/v8/v8.test.ts using checkSameOutput() function to compare Node.js and Bun output

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-18T05:23:24.403Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/telemetry-server.test.ts:91-100
Timestamp: 2025-10-18T05:23:24.403Z
Learning: In the Bun codebase, telemetry tests (test/js/bun/telemetry-*.test.ts) should focus on telemetry API behavior: configure/disable/isEnabled, callback signatures and invocation, request ID correlation, and error handling. HTTP protocol behaviors like status code normalization (e.g., 200 with empty body → 204) should be tested in HTTP server tests (test/js/bun/http/), not in telemetry tests. Keep separation of concerns: telemetry tests verify the telemetry API contract; HTTP tests verify HTTP semantics.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T04:55:33.099Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.

Applied to files:

  • test/regression/issue/05951.test.ts
  • packages/bun-types/bun.d.ts
  • src/js/thirdparty/ws.js
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always use `await using` or `using` to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : When spawning Bun processes in tests, use `bunExe` and `bunEnv` from `harness` to ensure the same build of Bun is used and debug logging is silenced

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T02:44:46.354Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/context-propagation.test.ts:1-1
Timestamp: 2025-10-19T02:44:46.354Z
Learning: In the Bun repository, standalone packages under packages/ (e.g., bun-vscode, bun-inspector-protocol, bun-plugin-yaml, bun-plugin-svelte, bun-debug-adapter-protocol, bun-otel) co-locate their tests with package source code using *.test.ts files. This follows standard npm/monorepo patterns. The test/ directory hierarchy (test/js/bun/, test/cli/, test/js/node/) is reserved for testing Bun's core runtime APIs and built-in functionality, not standalone packages.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/regression/issue/**/*.test.ts : Regression tests for specific issues go in `/test/regression/issue/${issueNumber}.test.ts`. Do not put tests without issue numbers in the regression directory

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to test/**/*.test.ts?(x) : Always use `port: 0` in tests - do not hardcode ports or use custom random port number functions

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to test/regression/issue/*.test.ts : Place regression tests for specific GitHub issues in `test/regression/issue/${issueNumber}.test.ts` with real issue numbers only

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : For multi-file tests, prefer `tempDir` and `Bun.spawn` over single-file tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-08T13:48:02.430Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 23373
File: test/js/bun/tarball/extract.test.ts:107-111
Timestamp: 2025-10-08T13:48:02.430Z
Learning: In Bun's test runner, use `expect(async () => { await ... }).toThrow()` to assert async rejections. Unlike Jest/Vitest, Bun does not require `await expect(...).rejects.toThrow()` - the async function wrapper with `.toThrow()` is the correct pattern for async error assertions in Bun tests.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Verify tests fail with `USE_SYSTEM_BUN=1 bun test <file>` and pass with `bun bd test <file>` - tests are invalid if they pass with USE_SYSTEM_BUN=1

Applied to files:

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📚 Learning: 2025-11-06T00:58:23.965Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 24417
File: test/js/bun/spawn/spawn.test.ts:903-918
Timestamp: 2025-11-06T00:58:23.965Z
Learning: In Bun test files, `await using` with spawn() is appropriate for long-running processes that need guaranteed cleanup on scope exit or when explicitly testing disposal behavior. For short-lived processes that exit naturally (e.g., console.log scripts), the pattern `const proc = spawn(...); await proc.exited;` is standard and more common, as evidenced by 24 instances vs 4 `await using` instances in test/js/bun/spawn/spawn.test.ts.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-25T17:20:19.041Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 24063
File: test/js/bun/telemetry/server-header-injection.test.ts:5-20
Timestamp: 2025-10-25T17:20:19.041Z
Learning: In the Bun telemetry codebase, tests are organized into two distinct layers: (1) Internal API tests in test/js/bun/telemetry/ use numeric InstrumentKind enum values to test Zig↔JS injection points and low-level integration; (2) Public API tests in packages/bun-otel/test/ use string InstrumentKind values ("http", "fetch", etc.) to test the public-facing BunSDK and instrumentation APIs. This separation allows internal tests to use efficient numeric enums for refactoring flexibility while the public API maintains a developer-friendly string-based interface.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Unit tests for specific features are organized by module (e.g., `/test/js/bun/`, `/test/js/node/`)

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-17T20:50:58.644Z
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23755
File: src/bun.js/api/bun/socket/Handlers.zig:154-159
Timestamp: 2025-10-17T20:50:58.644Z
Learning: In Bun socket configuration error messages (src/bun.js/api/bun/socket/Handlers.zig), use the user-facing JavaScript names "data" and "drain" instead of internal field names "onData" and "onWritable", as these are the names users see in the API according to SocketConfig.bindv2.ts.

Applied to files:

  • packages/bun-types/bun.d.ts
  • src/js/thirdparty/ws.js
  • src/bun.js/bindings/webcore/WebSocket.cpp
📚 Learning: 2025-10-19T02:52:37.412Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/tsconfig.json:1-15
Timestamp: 2025-10-19T02:52:37.412Z
Learning: In the Bun repository, packages under packages/ (e.g., bun-otel) can follow a TypeScript-first pattern where package.json exports point directly to .ts files (not compiled .js files). Bun natively runs TypeScript, so consumers import .ts sources directly and receive full type information without needing compiled .d.ts declaration files. For such packages, adding "declaration": true or "outDir" in tsconfig.json is unnecessary and would break the export structure.
<!-- [remove_learning]
ceedde95-980e-4898-a2c6-40ff73913664

Applied to files:

  • packages/bun-types/bun.d.ts
📚 Learning: 2025-11-14T16:07:01.064Z
Learnt from: RiskyMH
Repo: oven-sh/bun PR: 24719
File: docs/bundler/executables.mdx:527-560
Timestamp: 2025-11-14T16:07:01.064Z
Learning: In the Bun repository, certain bundler features like compile with code splitting (--compile --splitting) are CLI-only and not supported in the Bun.build() JavaScript API. Tests for CLI-only features use backend: "cli" flag (e.g., test/bundler/bundler_compile_splitting.test.ts). The CompileBuildConfig interface correctly restricts these with splitting?: never;. When documenting CLI-only bundler features, add a note clarifying they're not available via the programmatic API.

Applied to files:

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📚 Learning: 2025-10-01T21:59:54.571Z
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23169
File: src/bun.js/bindings/webcore/JSDOMConvertEnumeration.h:47-74
Timestamp: 2025-10-01T21:59:54.571Z
Learning: In the new bindings generator (bindgenv2) for `src/bun.js/bindings/webcore/JSDOMConvertEnumeration.h`, the context-aware enumeration conversion overloads intentionally use stricter validation (requiring `value.isString()` without ToString coercion), diverging from Web IDL semantics. This is a design decision documented in comments.

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.cpp
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to src/bun.js/bindings/**/*.cpp : Add iso subspaces for C++ classes with fields in JavaScript class bindings

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/src/symbols.txt : Add symbol names without leading underscore to src/symbols.txt for each new V8 API method

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to src/bun.js/bindings/**/*.cpp : Define properties using HashTableValue arrays in C++ JavaScript class bindings

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-11-12T04:11:52.293Z
Learnt from: cirospaciari
Repo: oven-sh/bun PR: 24622
File: src/deps/uws/us_socket_t.zig:112-113
Timestamp: 2025-11-12T04:11:52.293Z
Learning: In Bun's Zig codebase, when passing u32 values to C FFI functions that expect c_uint parameters, no explicit intCast is needed because c_uint is equivalent to u32 on Bun's target platforms and Zig allows implicit coercion between equivalent types. This pattern is used consistently throughout src/deps/uws/us_socket_t.zig in functions like setTimeout, setLongTimeout, and setKeepalive.

Applied to files:

  • src/http/websocket_client/CppWebSocket.zig
📚 Learning: 2025-10-26T04:50:17.892Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24086
File: src/bun.js/api/server.zig:2534-2535
Timestamp: 2025-10-26T04:50:17.892Z
Learning: In src/bun.js/api/server.zig, u32 is acceptable for route indices and websocket_context_index fields, as the practical limit of 4 billion contexts will never be reached.

Applied to files:

  • src/http/websocket_client/CppWebSocket.zig
📚 Learning: 2025-09-19T21:17:04.690Z
Learnt from: cirospaciari
Repo: oven-sh/bun PR: 22756
File: src/js/node/_http_server.ts:945-947
Timestamp: 2025-09-19T21:17:04.690Z
Learning: JSNodeHTTPServerSocket in src/bun.js/bindings/NodeHTTP.cpp implements both end() and close() methods. The end() method properly handles socket termination for both HTTP responses and raw CONNECT sockets by setting ended=true, checking buffered data, and flushing remaining data through the response context.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
📚 Learning: 2025-11-24T18:37:11.466Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/js/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:11.466Z
Learning: Write JS builtins for Bun's Node.js compatibility and APIs, and run `bun bd` after changes

Applied to files:

  • src/js/thirdparty/ws.js
📚 Learning: 2025-12-05T19:28:39.534Z
Learnt from: alii
Repo: oven-sh/bun PR: 25360
File: src/bake/hmr-runtime-client.ts:240-249
Timestamp: 2025-12-05T19:28:39.534Z
Learning: In Bun's HMR runtime client (src/bake/hmr-runtime-client.ts), when handling error events where `event.error` is falsy, do not wrap `event.message` in a new Error object. Doing so would create misleading stack frames that show the error originating from the HMR client code rather than the actual error location, which hinders debugging.

Applied to files:

  • src/js/thirdparty/ws.js
📚 Learning: 2025-12-23T06:50:31.577Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 25429
File: src/bun.js/bindings/helpers.h:422-422
Timestamp: 2025-12-23T06:50:31.577Z
Learning: In Bun's C++ bindings, when returning an empty JSC::Identifier and a VM is accessible, prefer using vm.propertyNames->emptyIdentifier over constructing with JSC::Identifier(JSC::Identifier::EmptyIdentifierFlag::EmptyIdentifier). The cached identifier from the VM's property names table is more efficient and consistent with WebKit upgrade patterns. Apply this guidance to src/bun.js/bindings/helpers.h and similar header files in the same bindings directory (i.e., any file that constructs an EmptyIdentifier).

Applied to files:

  • src/bun.js/bindings/webcore/WebSocket.h
🧬 Code graph analysis (3)
test/regression/issue/05951.test.ts (3)
test/harness.ts (1)
  • bunExe (102-105)
src/bun.js/bindings/webcore/WebSocket.cpp (2)
  • WebSocket (179-187)
  • WebSocket (189-221)
src/js/thirdparty/ws.js (1)
  • WebSocket (53-53)
src/js/thirdparty/ws.js (1)
src/js/node/_http_incoming.ts (2)
  • statusCode (354-356)
  • statusCode (357-360)
src/bun.js/bindings/webcore/WebSocket.h (1)
src/bun.js/bindings/webcore/WebSocket.cpp (6)
  • scriptExecutionContext (989-992)
  • scriptExecutionContext (989-989)
  • disablePendingActivity (1495-1499)
  • disablePendingActivity (1495-1495)
  • didClose (1248-1298)
  • didClose (1248-1248)
🔇 Additional comments (11)
src/bun.js/bindings/webcore/WebSocket.cpp (1)

1300-1304: upgradeStatusCode propagation is correctly wired and ordered

Capturing upgradeStatusCode in WebSocket::didConnect(...) and assigning it to m_upgradeStatusCode before invoking the no-arg didConnect() ensures that any JS observers (including the ws wrapper) see the correct HTTP status when open/upgrade-style events fire. The extern "C" shim cleanly forwards the new parameter, and the use of uint16_t is consistent with existing status/close-code sizing in this file.

Also applies to: 1510-1512

packages/bun-types/bun.d.ts (1)

3155-3158: Type surface for upgradeStatusCode matches native behavior and PR intent

Adding readonly upgradeStatusCode: number with the accompanying JSDoc accurately exposes the native u16 HTTP upgrade status code to users of Bun.WebSocket, and aligns with the C++/Zig wiring that stores this value on successful upgrades. No additional typing or overloads seem necessary here.

src/js/thirdparty/ws.js (1)

179-181: LGTM! Event handling correctly updated.

The warning is now only emitted for the redirect event, which is appropriate since upgrade and unexpected-response now have proper implementations below.

src/bun.js/bindings/webcore/WebSocket.h (2)

131-131: LGTM! Accessor properly exposes upgrade status code.

The public getter correctly exposes the upgrade status code with appropriate type (uint16_t) for HTTP status codes.


140-140: LGTM! didConnect signature and storage properly extended.

The changes correctly:

  • Extend didConnect to accept the upgrade status code parameter
  • Add private member m_upgradeStatusCode to store the value
  • Initialize the field to 0 (default value when status is not yet known)

The uint16_t type is appropriate for HTTP status codes.

Also applies to: 227-227

test/regression/issue/05951.test.ts (3)

4-239: Consider test reliability with external WebSocket services.

All tests rely on external WebSocket services (wss://echo.websocket.org and wss://httpbin.org), which could make tests flaky if:

  • Services are down or slow
  • Network connectivity issues occur
  • Rate limiting is applied

While using real WebSocket servers validates actual upgrade behavior (which aligns with the PR's goal of improving compatibility with tools like Playwright), consider:

  1. Adding retry logic for transient failures
  2. Documenting that these are integration tests requiring network access
  3. Potentially creating a local WebSocket test server for more reliable testing

However, if the goal is specifically to validate real-world upgrade behavior, the current approach is reasonable.


1-239: Good test coverage for the regression issue.

The test suite appropriately covers:

  • Warning elimination for both upgrade and unexpected-response events
  • Event emission and timing
  • Response object structure and content
  • Backward compatibility
  • Native upgradeStatusCode property exposure

This aligns well with the PR objectives of fixing issue #5951 (eliminating warnings and improving compatibility).


220-239: LGTM! Native WebSocket property test is well-structured.

This test properly:

  • Uses await new Promise pattern to handle async events
  • Validates both the value (101) and type (number) of upgradeStatusCode
  • Closes the WebSocket connection
  • Handles errors appropriately
src/http/websocket_client/CppWebSocket.zig (1)

17-18: LGTM! Zig-C++ boundary correctly extended.

The changes properly:

  • Extend the extern function signature to accept upgrade_status_code: u16
  • Extend the public wrapper method with the same parameter
  • Forward the parameter through the call chain
  • Maintain proper event loop enter/exit pattern

The u16 type correctly matches the C++ uint16_t type for HTTP status codes.

Also applies to: 54-59

src/bun.js/bindings/webcore/JSWebSocket.cpp (2)

85-85: LGTM! Property declaration follows WebKit binding conventions.

The upgradeStatusCode property is correctly declared as:

  • Read-only (appropriate for a status value)
  • Custom accessor with DOMAttribute semantics
  • Registered in the prototype hash table

This follows the pattern established by other WebSocket properties like readyState and bufferedAmount.

Also applies to: 330-330


450-461: LGTM! Getter implementation follows IDL binding patterns.

The getter correctly:

  • Retrieves the implementation object
  • Converts the native uint16_t value to JavaScript using IDLUnsignedShort
  • Uses the standard IDLAttribute<JSWebSocket>::get wrapper with appropriate error behavior

The implementation is consistent with other numeric property getters in this file.

Comment on lines +212 to +234
} else if (event === "unexpected-response") {
// The 'unexpected-response' event is emitted when the server responds with
// a non-101 status code. Since we can't intercept the HTTP response directly,
// we listen for 'error' events that might indicate a failed upgrade.
this.#ws.addEventListener(
"error",
(err) => {
// Emit unexpected-response event with mock objects
// Note: We don't have access to the actual request/response objects
const mockRequest = {
method: "GET",
url: this.#ws.url,
headers: {},
};
const mockResponse = {
statusCode: 0,
statusMessage: err?.message || "Connection failed",
headers: {},
};
this.emit("unexpected-response", mockRequest, mockResponse);
},
once,
);
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⚠️ Potential issue | 🟡 Minor

Unexpected-response implementation provides minimal detail.

The unexpected-response event always emits statusCode: 0 regardless of the actual HTTP status code returned by the server. This limits its utility for tools that need to inspect why the WebSocket upgrade failed (e.g., 404, 403, 401, etc.).

While the PR successfully adds the upgradeStatusCode property to the native WebSocket (which should contain the actual status), this event handler cannot access it during error scenarios because the upgrade failed and the WebSocket never fully initialized.

This is inherently a limitation of Bun's WebSocket implementation not exposing the HTTP response on connection failures. The current "best-effort" approach removes the warnings (meeting the PR objective) but provides limited debugging value.

Consider documenting this limitation: the unexpected-response event is emitted on errors, but the statusCode will always be 0, and the response object contains the error message, not actual HTTP response data.

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Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)
src/js/thirdparty/ws.js (1)

18-25: Bitmask collision prevents wiring both "upgrade" and "unexpected-response" listeners.

eventIds doesn’t define entries for "upgrade" or "unexpected-response", so eventIds[event] is undefined and const mask = 1 << eventIds[event]; yields mask === 1 for both. Because #onOrOnce only runs the wiring block when (this.#eventId & mask) !== mask, the first of these events you register sets bit 1, and subsequent registrations for the other event skip the wiring entirely.

Result: if user code attaches both handlers (e.g. ws.on("upgrade", ...) and ws.on("unexpected-response", ...)), only the first one gets its underlying addEventListener hook; the other will never fire, even though the listener is registered on the EventEmitter.

To make both events usable on the same instance, they should have distinct bits in eventIds:

Proposed fix: give the new events dedicated IDs
-const eventIds = {
-  open: 1,
-  close: 2,
-  message: 3,
-  error: 4,
-  ping: 5,
-  pong: 6,
-};
+const eventIds = {
+  open: 1,
+  close: 2,
+  message: 3,
+  error: 4,
+  ping: 5,
+  pong: 6,
+  upgrade: 7,
+  "unexpected-response": 8,
+};

This keeps the existing bitset scheme intact, ensures each event’s wiring runs once, and avoids cross‑interference between "upgrade" and "unexpected-response" (and with "redirect", which remains outside the map).

Also applies to: 178-234

♻️ Duplicate comments (2)
src/http/websocket_client/WebSocketUpgradeClient.zig (1)

551-551: Remove redundant intCast.

The @intCast is unnecessary since response.status_code is already u16 and didConnect expects u16.

Based on learnings, in Bun's Zig codebase, no explicit intCast is needed when passing values between equivalent types.

🔎 Proposed fix
-ws.didConnect(socket.socket.get().?, overflow.ptr, overflow.len, if (deflate_result.enabled) &deflate_result.params else null, @intCast(response.status_code));
+ws.didConnect(socket.socket.get().?, overflow.ptr, overflow.len, if (deflate_result.enabled) &deflate_result.params else null, response.status_code);
test/regression/issue/05951.test.ts (1)

69-71: Replace setTimeout with condition-based waiting.

This test uses an arbitrary 2-second delay, which violates the coding guideline: "Never wait for time to pass in tests; always wait for the condition to be met."

Consider tracking when the expected events (error and/or unexpected-response) have fired, then exit immediately or use Promise-based synchronization.

As per coding guidelines, avoid setTimeout in tests.

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📥 Commits

Reviewing files that changed from the base of the PR and between fe79358 and 61c85b5.

📒 Files selected for processing (8)
  • packages/bun-types/bun.d.ts
  • src/bun.js/bindings/webcore/JSWebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.h
  • src/http/websocket_client/CppWebSocket.zig
  • src/http/websocket_client/WebSocketUpgradeClient.zig
  • src/js/thirdparty/ws.js
  • test/regression/issue/05951.test.ts
🧰 Additional context used
📓 Path-based instructions (9)
src/js/{builtins,node,bun,thirdparty,internal}/**/*.{ts,js}

📄 CodeRabbit inference engine (src/js/CLAUDE.md)

src/js/{builtins,node,bun,thirdparty,internal}/**/*.{ts,js}: Use .$call() and .$apply() instead of .call() and .apply() to prevent user tampering with function invocation
Use string literal require() statements only; dynamic requires are not permitted
Export modules using export default { ... } syntax; modules are NOT ES modules
Use JSC intrinsics (prefixed with $) such as $Array.from(), $isCallable(), and $newArrayWithSize() for performance-critical operations
Use private globals and methods with $ prefix (e.g., $Array, map.$set()) instead of public JavaScript globals
Use $debug() for debug logging and $assert() for assertions; both are stripped in release builds
Validate function arguments using validators from internal/validators and throw $ERR_* error codes for invalid arguments
Use process.platform and process.arch for platform detection; these values are inlined and dead-code eliminated at build time

Files:

  • src/js/thirdparty/ws.js
test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}

📄 CodeRabbit inference engine (test/CLAUDE.md)

test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}: Use bun:test with files that end in *.test.{ts,js,jsx,tsx,mjs,cjs}
Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time
Never use hardcoded port numbers in tests. Always use port: 0 to get a random port
Prefer concurrent tests over sequential tests using test.concurrent or describe.concurrent when multiple tests spawn processes or write files, unless it's very difficult to make them concurrent
When spawning Bun processes in tests, use bunExe and bunEnv from harness to ensure the same build of Bun is used and debug logging is silenced
Use -e flag for single-file tests when spawning Bun processes
Use tempDir() from harness to create temporary directories with files for multi-file tests instead of creating files manually
Prefer async/await over callbacks in tests
When callbacks must be used and it's just a single callback, use Promise.withResolvers to create a promise that can be resolved or rejected from a callback
Do not set a timeout on tests. Bun already has timeouts
Use Buffer.alloc(count, fill).toString() instead of 'A'.repeat(count) to create repetitive strings in tests, as ''.repeat is very slow in debug JavaScriptCore builds
Use describe blocks for grouping related tests
Always use await using or using to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc
Always check exit codes and test error scenarios in error tests
Use describe.each() for parameterized tests
Use toMatchSnapshot() for snapshot testing
Use beforeAll(), afterEach(), beforeEach() for setup/teardown in tests
Track resources (servers, clients) in arrays for cleanup in afterEach()

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/**/*.test.ts

📄 CodeRabbit inference engine (test/CLAUDE.md)

Regression tests for specific issues go in /test/regression/issue/${issueNumber}.test.ts. Do not put tests without issue numbers in the regression directory

Files:

  • test/regression/issue/05951.test.ts
**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

**/*.test.ts?(x): Never use bun test directly - always use bun bd test to run tests with debug build changes
For single-file tests, prefer -e flag over tempDir
For multi-file tests, prefer tempDir and Bun.spawn over single-file tests
Use normalizeBunSnapshot to normalize snapshot output of tests
Never write tests that check for 'panic', 'uncaught exception', or similar strings in test output
Use tempDir from harness to create temporary directories - do not use tmpdirSync or fs.mkdtempSync
When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure
Do not write flaky tests - do not use setTimeout in tests; instead await the condition to be met
Verify tests fail with USE_SYSTEM_BUN=1 bun test <file> and pass with bun bd test <file> - tests are invalid if they pass with USE_SYSTEM_BUN=1
Test files must end with .test.ts or .test.tsx
Avoid shell commands like find or grep in tests - use Bun's Glob and built-in tools instead

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/*.test.ts

📄 CodeRabbit inference engine (CLAUDE.md)

Place regression tests for specific GitHub issues in test/regression/issue/${issueNumber}.test.ts with real issue numbers only

Files:

  • test/regression/issue/05951.test.ts
test/**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

Always use port: 0 in tests - do not hardcode ports or use custom random port number functions

Files:

  • test/regression/issue/05951.test.ts
src/**/*.zig

📄 CodeRabbit inference engine (src/CLAUDE.md)

src/**/*.zig: Private fields in Zig are fully supported using the # prefix: struct { #foo: u32 };
Use decl literals in Zig for declaration initialization: const decl: Decl = .{ .binding = 0, .value = 0 };
Prefer @import at the bottom of the file (auto formatter will move them automatically)

Files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
  • src/http/websocket_client/CppWebSocket.zig
**/*.zig

📄 CodeRabbit inference engine (CLAUDE.md)

In Zig code, be careful with allocators and use defer for cleanup

Files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
  • src/http/websocket_client/CppWebSocket.zig
src/bun.js/bindings/**/*.cpp

📄 CodeRabbit inference engine (CLAUDE.md)

src/bun.js/bindings/**/*.cpp: Create classes in three parts in C++ when there is a public constructor: Foo (JSDestructibleObject), FooPrototype (JSNonFinalObject), and FooConstructor (InternalFunction)
Define properties using HashTableValue arrays in C++ JavaScript class bindings
Add iso subspaces for C++ classes with fields in JavaScript class bindings
Cache structures in ZigGlobalObject for JavaScript class bindings

Files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
  • src/bun.js/bindings/webcore/WebSocket.cpp
🧠 Learnings (35)
📚 Learning: 2025-10-17T20:50:58.644Z
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23755
File: src/bun.js/api/bun/socket/Handlers.zig:154-159
Timestamp: 2025-10-17T20:50:58.644Z
Learning: In Bun socket configuration error messages (src/bun.js/api/bun/socket/Handlers.zig), use the user-facing JavaScript names "data" and "drain" instead of internal field names "onData" and "onWritable", as these are the names users see in the API according to SocketConfig.bindv2.ts.

Applied to files:

  • src/js/thirdparty/ws.js
  • packages/bun-types/bun.d.ts
📚 Learning: 2025-11-14T16:07:01.064Z
Learnt from: RiskyMH
Repo: oven-sh/bun PR: 24719
File: docs/bundler/executables.mdx:527-560
Timestamp: 2025-11-14T16:07:01.064Z
Learning: In the Bun repository, certain bundler features like compile with code splitting (--compile --splitting) are CLI-only and not supported in the Bun.build() JavaScript API. Tests for CLI-only features use backend: "cli" flag (e.g., test/bundler/bundler_compile_splitting.test.ts). The CompileBuildConfig interface correctly restricts these with splitting?: never;. When documenting CLI-only bundler features, add a note clarifying they're not available via the programmatic API.

Applied to files:

  • src/js/thirdparty/ws.js
📚 Learning: 2025-12-05T19:28:39.534Z
Learnt from: alii
Repo: oven-sh/bun PR: 25360
File: src/bake/hmr-runtime-client.ts:240-249
Timestamp: 2025-12-05T19:28:39.534Z
Learning: In Bun's HMR runtime client (src/bake/hmr-runtime-client.ts), when handling error events where `event.error` is falsy, do not wrap `event.message` in a new Error object. Doing so would create misleading stack frames that show the error originating from the HMR client code rather than the actual error location, which hinders debugging.

Applied to files:

  • src/js/thirdparty/ws.js
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add corresponding test cases to test/v8/v8.test.ts using checkSameOutput() function to compare Node.js and Bun output

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : When spawning Bun processes in tests, use `bunExe` and `bunEnv` from `harness` to ensure the same build of Bun is used and debug logging is silenced

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always use `await using` or `using` to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-18T05:23:24.403Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/telemetry-server.test.ts:91-100
Timestamp: 2025-10-18T05:23:24.403Z
Learning: In the Bun codebase, telemetry tests (test/js/bun/telemetry-*.test.ts) should focus on telemetry API behavior: configure/disable/isEnabled, callback signatures and invocation, request ID correlation, and error handling. HTTP protocol behaviors like status code normalization (e.g., 200 with empty body → 204) should be tested in HTTP server tests (test/js/bun/http/), not in telemetry tests. Keep separation of concerns: telemetry tests verify the telemetry API contract; HTTP tests verify HTTP semantics.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T04:55:33.099Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.

Applied to files:

  • test/regression/issue/05951.test.ts
  • packages/bun-types/bun.d.ts
📚 Learning: 2025-10-26T01:32:04.844Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24082
File: test/cli/test/coverage.test.ts:60-112
Timestamp: 2025-10-26T01:32:04.844Z
Learning: In the Bun repository test files (test/cli/test/*.test.ts), when spawning Bun CLI commands with Bun.spawnSync for testing, prefer using stdio: ["inherit", "inherit", "inherit"] to inherit stdio streams rather than piping them.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T02:44:46.354Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/context-propagation.test.ts:1-1
Timestamp: 2025-10-19T02:44:46.354Z
Learning: In the Bun repository, standalone packages under packages/ (e.g., bun-vscode, bun-inspector-protocol, bun-plugin-yaml, bun-plugin-svelte, bun-debug-adapter-protocol, bun-otel) co-locate their tests with package source code using *.test.ts files. This follows standard npm/monorepo patterns. The test/ directory hierarchy (test/js/bun/, test/cli/, test/js/node/) is reserved for testing Bun's core runtime APIs and built-in functionality, not standalone packages.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Verify tests fail with `USE_SYSTEM_BUN=1 bun test <file>` and pass with `bun bd test <file>` - tests are invalid if they pass with USE_SYSTEM_BUN=1

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Use `normalizeBunSnapshot` to normalize snapshot output of tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Do not write flaky tests - do not use `setTimeout` in tests; instead await the condition to be met

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-03T01:30:58.001Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 21728
File: test/js/valkey/valkey.test.ts:264-271
Timestamp: 2025-09-03T01:30:58.001Z
Learning: For test/js/valkey/valkey.test.ts PUB/SUB tests, avoid arbitrary sleeps and async-forEach. Instead, resolve a Promise from the subscriber callback when the expected number of messages is observed and await it with a bounded timeout (e.g., withTimeout + Promise.withResolvers) to account for Redis server→subscriber propagation.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always check exit codes and test error scenarios in error tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:57:56.685Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:268-276
Timestamp: 2025-09-20T00:57:56.685Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods like ctx.redis.set() - the maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Prefer async/await over callbacks in tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:58:38.042Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:561-564
Timestamp: 2025-09-20T00:58:38.042Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods (like ctx.redis.set(), ctx.redis.unsubscribe(), etc.) - Bun's Redis client implementation differs from Node.js and can throw synchronously even for async methods. The maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not set a timeout on tests. Bun already has timeouts

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-06T00:58:23.965Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 24417
File: test/js/bun/spawn/spawn.test.ts:903-918
Timestamp: 2025-11-06T00:58:23.965Z
Learning: In Bun test files, `await using` with spawn() is appropriate for long-running processes that need guaranteed cleanup on scope exit or when explicitly testing disposal behavior. For short-lived processes that exit naturally (e.g., console.log scripts), the pattern `const proc = spawn(...); await proc.exited;` is standard and more common, as evidenced by 24 instances vs 4 `await using` instances in test/js/bun/spawn/spawn.test.ts.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-08T04:06:33.198Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24491
File: test/js/bun/transpiler/declare-global.test.ts:17-17
Timestamp: 2025-11-08T04:06:33.198Z
Learning: In Bun test files, `await using` with Bun.spawn() is the preferred pattern for spawned processes regardless of whether they are short-lived or long-running. Do not suggest replacing `await using proc = Bun.spawn(...)` with `const proc = Bun.spawn(...); await proc.exited;`.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-25T17:20:19.041Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 24063
File: test/js/bun/telemetry/server-header-injection.test.ts:5-20
Timestamp: 2025-10-25T17:20:19.041Z
Learning: In the Bun telemetry codebase, tests are organized into two distinct layers: (1) Internal API tests in test/js/bun/telemetry/ use numeric InstrumentKind enum values to test Zig↔JS injection points and low-level integration; (2) Public API tests in packages/bun-otel/test/ use string InstrumentKind values ("http", "fetch", etc.) to test the public-facing BunSDK and instrumentation APIs. This separation allows internal tests to use efficient numeric enums for refactoring flexibility while the public API maintains a developer-friendly string-based interface.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T02:52:37.412Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/tsconfig.json:1-15
Timestamp: 2025-10-19T02:52:37.412Z
Learning: In the Bun repository, packages under packages/ (e.g., bun-otel) can follow a TypeScript-first pattern where package.json exports point directly to .ts files (not compiled .js files). Bun natively runs TypeScript, so consumers import .ts sources directly and receive full type information without needing compiled .d.ts declaration files. For such packages, adding "declaration": true or "outDir" in tsconfig.json is unnecessary and would break the export structure.
<!-- [remove_learning]
ceedde95-980e-4898-a2c6-40ff73913664

Applied to files:

  • packages/bun-types/bun.d.ts
📚 Learning: 2025-11-12T04:11:52.293Z
Learnt from: cirospaciari
Repo: oven-sh/bun PR: 24622
File: src/deps/uws/us_socket_t.zig:112-113
Timestamp: 2025-11-12T04:11:52.293Z
Learning: In Bun's Zig codebase, when passing u32 values to C FFI functions that expect c_uint parameters, no explicit intCast is needed because c_uint is equivalent to u32 on Bun's target platforms and Zig allows implicit coercion between equivalent types. This pattern is used consistently throughout src/deps/uws/us_socket_t.zig in functions like setTimeout, setLongTimeout, and setKeepalive.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
  • src/http/websocket_client/CppWebSocket.zig
📚 Learning: 2025-09-04T02:04:43.094Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 22278
File: src/ast/E.zig:980-1003
Timestamp: 2025-09-04T02:04:43.094Z
Learning: In Bun's Zig codebase, `as(i32, u8_or_u16_value)` is sufficient for casting u8/u16 to i32 in comparison operations. `intCast` is not required in this context, and the current casting approach compiles successfully.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
📚 Learning: 2025-10-24T10:43:09.398Z
Learnt from: fmguerreiro
Repo: oven-sh/bun PR: 23774
File: src/install/PackageManager/updatePackageJSONAndInstall.zig:548-548
Timestamp: 2025-10-24T10:43:09.398Z
Learning: In Bun's Zig codebase, the `as(usize, intCast(...))` cast pattern triggers a Zig compiler bug that causes compilation to hang indefinitely when used in complex control flow contexts (loops + short-circuit operators + optional unwrapping). Avoid this pattern and use simpler alternatives like just `intCast(...)` if type casting is necessary.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
📚 Learning: 2025-10-26T04:50:17.892Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24086
File: src/bun.js/api/server.zig:2534-2535
Timestamp: 2025-10-26T04:50:17.892Z
Learning: In src/bun.js/api/server.zig, u32 is acceptable for route indices and websocket_context_index fields, as the practical limit of 4 billion contexts will never be reached.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
  • src/http/websocket_client/CppWebSocket.zig
📚 Learning: 2025-09-19T21:17:04.690Z
Learnt from: cirospaciari
Repo: oven-sh/bun PR: 22756
File: src/js/node/_http_server.ts:945-947
Timestamp: 2025-09-19T21:17:04.690Z
Learning: JSNodeHTTPServerSocket in src/bun.js/bindings/NodeHTTP.cpp implements both end() and close() methods. The end() method properly handles socket termination for both HTTP responses and raw CONNECT sockets by setting ended=true, checking buffered data, and flushing remaining data through the response context.

Applied to files:

  • src/http/websocket_client/WebSocketUpgradeClient.zig
📚 Learning: 2025-10-01T21:59:54.571Z
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23169
File: src/bun.js/bindings/webcore/JSDOMConvertEnumeration.h:47-74
Timestamp: 2025-10-01T21:59:54.571Z
Learning: In the new bindings generator (bindgenv2) for `src/bun.js/bindings/webcore/JSDOMConvertEnumeration.h`, the context-aware enumeration conversion overloads intentionally use stricter validation (requiring `value.isString()` without ToString coercion), diverging from Web IDL semantics. This is a design decision documented in comments.

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to src/bun.js/bindings/**/*.cpp : Add iso subspaces for C++ classes with fields in JavaScript class bindings

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/src/symbols.txt : Add symbol names without leading underscore to src/symbols.txt for each new V8 API method

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to src/bun.js/bindings/**/*.cpp : Define properties using HashTableValue arrays in C++ JavaScript class bindings

Applied to files:

  • src/bun.js/bindings/webcore/JSWebSocket.cpp
📚 Learning: 2025-12-23T06:50:31.577Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 25429
File: src/bun.js/bindings/helpers.h:422-422
Timestamp: 2025-12-23T06:50:31.577Z
Learning: In Bun's C++ bindings, when returning an empty JSC::Identifier and a VM is accessible, prefer using vm.propertyNames->emptyIdentifier over constructing with JSC::Identifier(JSC::Identifier::EmptyIdentifierFlag::EmptyIdentifier). The cached identifier from the VM's property names table is more efficient and consistent with WebKit upgrade patterns. Apply this guidance to src/bun.js/bindings/helpers.h and similar header files in the same bindings directory (i.e., any file that constructs an EmptyIdentifier).

Applied to files:

  • src/bun.js/bindings/webcore/WebSocket.h
🧬 Code graph analysis (3)
src/js/thirdparty/ws.js (1)
src/js/node/_http_incoming.ts (2)
  • statusCode (354-356)
  • statusCode (357-360)
test/regression/issue/05951.test.ts (4)
test/harness.ts (1)
  • bunExe (102-105)
test/js/bun/http/bun-websocket-cpu-fixture.js (1)
  • ws (25-25)
src/bun.js/bindings/webcore/WebSocket.cpp (2)
  • WebSocket (179-187)
  • WebSocket (189-221)
src/js/thirdparty/ws.js (1)
  • WebSocket (53-53)
src/bun.js/bindings/webcore/WebSocket.h (1)
src/bun.js/bindings/webcore/WebSocket.cpp (6)
  • scriptExecutionContext (989-992)
  • scriptExecutionContext (989-989)
  • didConnect (1037-1067)
  • didConnect (1037-1037)
  • didConnect (1300-1337)
  • didConnect (1300-1300)
🔇 Additional comments (7)
packages/bun-types/bun.d.ts (1)

3155-3158: upgradeStatusCode typing looks correct.

Read‑only numeric status code on WebSocket matches the new native field and usage in ws.js; the JSDoc is clear enough for now.

src/bun.js/bindings/webcore/WebSocket.h (1)

131-131: LGTM! Clean addition of upgradeStatusCode property.

The implementation follows good practices:

  • Member is private with sensible default (0)
  • Getter is public, const, and inline
  • Signature updates are consistent across the interface

Also applies to: 140-140, 227-227

test/regression/issue/05951.test.ts (1)

227-246: LGTM! Well-structured test with proper async handling.

This test correctly:

  • Uses Promise-based synchronization instead of setTimeout
  • Tests the native WebSocket property directly
  • Includes proper error handling
  • Follows the coding guideline to avoid arbitrary time delays
src/http/websocket_client/CppWebSocket.zig (1)

17-17: LGTM! Signature updates are consistent.

The changes correctly:

  • Add upgrade_status_code: u16 parameter to the extern function signature
  • Update the public didConnect method signature
  • Forward the parameter without unnecessary type conversions

Also applies to: 54-54, 58-58

src/bun.js/bindings/webcore/WebSocket.cpp (2)

1300-1303: LGTM! Status code storage is correctly positioned.

The upgradeStatusCode is stored immediately after clearing the upgrade client and before processing deflate parameters, which is the appropriate order.


1510-1512: LGTM! Extern wrapper correctly forwards upgradeStatusCode.

The C wrapper properly accepts and forwards the upgradeStatusCode parameter to the C++ didConnect method.

src/bun.js/bindings/webcore/JSWebSocket.cpp (1)

85-85: LGTM! JavaScript binding follows established patterns.

The upgradeStatusCode property binding correctly:

  • Uses IDLUnsignedShort type (appropriate for uint16_t)
  • Declares as ReadOnly, CustomAccessor, DOMAttribute
  • Follows the same pattern as other readonly properties like readyState and bufferedAmount
  • Uses the IDLAttribute<JSWebSocket>::get helper consistently

Also applies to: 330-330, 450-461

- Remove setTimeout calls per coding guidelines
- Use local WebSocketServer instead of external services
- Remove console.log pollution - only spawn when checking stderr
- Tests are now faster (1.4s) and more reliable
- All 6 tests pass
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Actionable comments posted: 2

📜 Review details

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📥 Commits

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📒 Files selected for processing (1)
  • test/regression/issue/05951.test.ts
🧰 Additional context used
📓 Path-based instructions (5)
test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}

📄 CodeRabbit inference engine (test/CLAUDE.md)

test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}: Use bun:test with files that end in *.test.{ts,js,jsx,tsx,mjs,cjs}
Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time
Never use hardcoded port numbers in tests. Always use port: 0 to get a random port
Prefer concurrent tests over sequential tests using test.concurrent or describe.concurrent when multiple tests spawn processes or write files, unless it's very difficult to make them concurrent
When spawning Bun processes in tests, use bunExe and bunEnv from harness to ensure the same build of Bun is used and debug logging is silenced
Use -e flag for single-file tests when spawning Bun processes
Use tempDir() from harness to create temporary directories with files for multi-file tests instead of creating files manually
Prefer async/await over callbacks in tests
When callbacks must be used and it's just a single callback, use Promise.withResolvers to create a promise that can be resolved or rejected from a callback
Do not set a timeout on tests. Bun already has timeouts
Use Buffer.alloc(count, fill).toString() instead of 'A'.repeat(count) to create repetitive strings in tests, as ''.repeat is very slow in debug JavaScriptCore builds
Use describe blocks for grouping related tests
Always use await using or using to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc
Always check exit codes and test error scenarios in error tests
Use describe.each() for parameterized tests
Use toMatchSnapshot() for snapshot testing
Use beforeAll(), afterEach(), beforeEach() for setup/teardown in tests
Track resources (servers, clients) in arrays for cleanup in afterEach()

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/**/*.test.ts

📄 CodeRabbit inference engine (test/CLAUDE.md)

Regression tests for specific issues go in /test/regression/issue/${issueNumber}.test.ts. Do not put tests without issue numbers in the regression directory

Files:

  • test/regression/issue/05951.test.ts
**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

**/*.test.ts?(x): Never use bun test directly - always use bun bd test to run tests with debug build changes
For single-file tests, prefer -e flag over tempDir
For multi-file tests, prefer tempDir and Bun.spawn over single-file tests
Use normalizeBunSnapshot to normalize snapshot output of tests
Never write tests that check for 'panic', 'uncaught exception', or similar strings in test output
Use tempDir from harness to create temporary directories - do not use tmpdirSync or fs.mkdtempSync
When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure
Do not write flaky tests - do not use setTimeout in tests; instead await the condition to be met
Verify tests fail with USE_SYSTEM_BUN=1 bun test <file> and pass with bun bd test <file> - tests are invalid if they pass with USE_SYSTEM_BUN=1
Test files must end with .test.ts or .test.tsx
Avoid shell commands like find or grep in tests - use Bun's Glob and built-in tools instead

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/*.test.ts

📄 CodeRabbit inference engine (CLAUDE.md)

Place regression tests for specific GitHub issues in test/regression/issue/${issueNumber}.test.ts with real issue numbers only

Files:

  • test/regression/issue/05951.test.ts
test/**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

Always use port: 0 in tests - do not hardcode ports or use custom random port number functions

Files:

  • test/regression/issue/05951.test.ts
🧠 Learnings (21)
📓 Common learnings
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23755
File: src/bun.js/api/bun/socket/Handlers.zig:154-159
Timestamp: 2025-10-17T20:50:58.644Z
Learning: In Bun socket configuration error messages (src/bun.js/api/bun/socket/Handlers.zig), use the user-facing JavaScript names "data" and "drain" instead of internal field names "onData" and "onWritable", as these are the names users see in the API according to SocketConfig.bindv2.ts.
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add corresponding test cases to test/v8/v8.test.ts using checkSameOutput() function to compare Node.js and Bun output

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : When spawning Bun processes in tests, use `bunExe` and `bunEnv` from `harness` to ensure the same build of Bun is used and debug logging is silenced

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-18T05:23:24.403Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/telemetry-server.test.ts:91-100
Timestamp: 2025-10-18T05:23:24.403Z
Learning: In the Bun codebase, telemetry tests (test/js/bun/telemetry-*.test.ts) should focus on telemetry API behavior: configure/disable/isEnabled, callback signatures and invocation, request ID correlation, and error handling. HTTP protocol behaviors like status code normalization (e.g., 200 with empty body → 204) should be tested in HTTP server tests (test/js/bun/http/), not in telemetry tests. Keep separation of concerns: telemetry tests verify the telemetry API contract; HTTP tests verify HTTP semantics.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always use `await using` or `using` to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T04:55:33.099Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T02:44:46.354Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/context-propagation.test.ts:1-1
Timestamp: 2025-10-19T02:44:46.354Z
Learning: In the Bun repository, standalone packages under packages/ (e.g., bun-vscode, bun-inspector-protocol, bun-plugin-yaml, bun-plugin-svelte, bun-debug-adapter-protocol, bun-otel) co-locate their tests with package source code using *.test.ts files. This follows standard npm/monorepo patterns. The test/ directory hierarchy (test/js/bun/, test/cli/, test/js/node/) is reserved for testing Bun's core runtime APIs and built-in functionality, not standalone packages.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-26T01:32:04.844Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24082
File: test/cli/test/coverage.test.ts:60-112
Timestamp: 2025-10-26T01:32:04.844Z
Learning: In the Bun repository test files (test/cli/test/*.test.ts), when spawning Bun CLI commands with Bun.spawnSync for testing, prefer using stdio: ["inherit", "inherit", "inherit"] to inherit stdio streams rather than piping them.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Verify tests fail with `USE_SYSTEM_BUN=1 bun test <file>` and pass with `bun bd test <file>` - tests are invalid if they pass with USE_SYSTEM_BUN=1

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Use `normalizeBunSnapshot` to normalize snapshot output of tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Do not write flaky tests - do not use `setTimeout` in tests; instead await the condition to be met

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-03T01:30:58.001Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 21728
File: test/js/valkey/valkey.test.ts:264-271
Timestamp: 2025-09-03T01:30:58.001Z
Learning: For test/js/valkey/valkey.test.ts PUB/SUB tests, avoid arbitrary sleeps and async-forEach. Instead, resolve a Promise from the subscriber callback when the expected number of messages is observed and await it with a bounded timeout (e.g., withTimeout + Promise.withResolvers) to account for Redis server→subscriber propagation.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always check exit codes and test error scenarios in error tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Prefer async/await over callbacks in tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:57:56.685Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:268-276
Timestamp: 2025-09-20T00:57:56.685Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods like ctx.redis.set() - the maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:58:38.042Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:561-564
Timestamp: 2025-09-20T00:58:38.042Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods (like ctx.redis.set(), ctx.redis.unsubscribe(), etc.) - Bun's Redis client implementation differs from Node.js and can throw synchronously even for async methods. The maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not set a timeout on tests. Bun already has timeouts

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Unit tests for specific features are organized by module (e.g., `/test/js/bun/`, `/test/js/node/`)

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-25T17:20:19.041Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 24063
File: test/js/bun/telemetry/server-header-injection.test.ts:5-20
Timestamp: 2025-10-25T17:20:19.041Z
Learning: In the Bun telemetry codebase, tests are organized into two distinct layers: (1) Internal API tests in test/js/bun/telemetry/ use numeric InstrumentKind enum values to test Zig↔JS injection points and low-level integration; (2) Public API tests in packages/bun-otel/test/ use string InstrumentKind values ("http", "fetch", etc.) to test the public-facing BunSDK and instrumentation APIs. This separation allows internal tests to use efficient numeric enums for refactoring flexibility while the public API maintains a developer-friendly string-based interface.

Applied to files:

  • test/regression/issue/05951.test.ts
🧬 Code graph analysis (1)
test/regression/issue/05951.test.ts (4)
test/harness.ts (1)
  • bunExe (102-105)
src/bun.js/bindings/webcore/WebSocket.cpp (2)
  • WebSocket (179-187)
  • WebSocket (189-221)
src/js/thirdparty/ws.js (1)
  • WebSocket (53-53)
test/js/bun/http/bun-websocket-cpu-fixture.js (1)
  • ws (25-25)
🔇 Additional comments (6)
test/regression/issue/05951.test.ts (6)

1-3: LGTM!

Proper imports for a regression test using the test harness and ws library.


58-86: LGTM!

Proper event ordering test with Promise-based synchronization and correct resource cleanup. No flaky setTimeout patterns used.


88-111: LGTM!

Comprehensive validation of the upgrade event's response object properties with proper async handling.


113-131: LGTM!

Good backward compatibility test ensuring the WebSocket works correctly without an upgrade listener.


133-152: LGTM!

Excellent test coverage of the native WebSocket property, separate from the ws wrapper tests. Validates both the value and type of upgradeStatusCode.


8-31: The guideline "always check exit codes and test error scenarios in error tests" applies specifically to tests that verify error behavior, not tests verifying the absence of errors or warnings during normal operation. This test is checking that no warning is emitted—a negative test—not testing an error scenario. The current structure of reading stderr before assertions already follows the recommended pattern for spawning processes in tests.

- Wrap tests in describe.concurrent block for parallel execution
- Add exit code checks for spawned processes
- Tests now run in 773ms (50% faster than sequential)
- All tests still pass with proper error handling
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📒 Files selected for processing (1)
  • test/regression/issue/05951.test.ts
🧰 Additional context used
📓 Path-based instructions (5)
test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}

📄 CodeRabbit inference engine (test/CLAUDE.md)

test/**/*.test.{ts,js,jsx,tsx,mjs,cjs}: Use bun:test with files that end in *.test.{ts,js,jsx,tsx,mjs,cjs}
Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time
Never use hardcoded port numbers in tests. Always use port: 0 to get a random port
Prefer concurrent tests over sequential tests using test.concurrent or describe.concurrent when multiple tests spawn processes or write files, unless it's very difficult to make them concurrent
When spawning Bun processes in tests, use bunExe and bunEnv from harness to ensure the same build of Bun is used and debug logging is silenced
Use -e flag for single-file tests when spawning Bun processes
Use tempDir() from harness to create temporary directories with files for multi-file tests instead of creating files manually
Prefer async/await over callbacks in tests
When callbacks must be used and it's just a single callback, use Promise.withResolvers to create a promise that can be resolved or rejected from a callback
Do not set a timeout on tests. Bun already has timeouts
Use Buffer.alloc(count, fill).toString() instead of 'A'.repeat(count) to create repetitive strings in tests, as ''.repeat is very slow in debug JavaScriptCore builds
Use describe blocks for grouping related tests
Always use await using or using to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc
Always check exit codes and test error scenarios in error tests
Use describe.each() for parameterized tests
Use toMatchSnapshot() for snapshot testing
Use beforeAll(), afterEach(), beforeEach() for setup/teardown in tests
Track resources (servers, clients) in arrays for cleanup in afterEach()

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/**/*.test.ts

📄 CodeRabbit inference engine (test/CLAUDE.md)

Regression tests for specific issues go in /test/regression/issue/${issueNumber}.test.ts. Do not put tests without issue numbers in the regression directory

Files:

  • test/regression/issue/05951.test.ts
**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

**/*.test.ts?(x): Never use bun test directly - always use bun bd test to run tests with debug build changes
For single-file tests, prefer -e flag over tempDir
For multi-file tests, prefer tempDir and Bun.spawn over single-file tests
Use normalizeBunSnapshot to normalize snapshot output of tests
Never write tests that check for 'panic', 'uncaught exception', or similar strings in test output
Use tempDir from harness to create temporary directories - do not use tmpdirSync or fs.mkdtempSync
When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure
Do not write flaky tests - do not use setTimeout in tests; instead await the condition to be met
Verify tests fail with USE_SYSTEM_BUN=1 bun test <file> and pass with bun bd test <file> - tests are invalid if they pass with USE_SYSTEM_BUN=1
Test files must end with .test.ts or .test.tsx
Avoid shell commands like find or grep in tests - use Bun's Glob and built-in tools instead

Files:

  • test/regression/issue/05951.test.ts
test/regression/issue/*.test.ts

📄 CodeRabbit inference engine (CLAUDE.md)

Place regression tests for specific GitHub issues in test/regression/issue/${issueNumber}.test.ts with real issue numbers only

Files:

  • test/regression/issue/05951.test.ts
test/**/*.test.ts?(x)

📄 CodeRabbit inference engine (CLAUDE.md)

Always use port: 0 in tests - do not hardcode ports or use custom random port number functions

Files:

  • test/regression/issue/05951.test.ts
🧠 Learnings (27)
📓 Common learnings
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.
Learnt from: taylordotfish
Repo: oven-sh/bun PR: 23755
File: src/bun.js/api/bun/socket/Handlers.zig:154-159
Timestamp: 2025-10-17T20:50:58.644Z
Learning: In Bun socket configuration error messages (src/bun.js/api/bun/socket/Handlers.zig), use the user-facing JavaScript names "data" and "drain" instead of internal field names "onData" and "onWritable", as these are the names users see in the API according to SocketConfig.bindv2.ts.
📚 Learning: 2025-11-24T18:36:59.706Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:36:59.706Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add corresponding test cases to test/v8/v8.test.ts using checkSameOutput() function to compare Node.js and Bun output

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : When spawning Bun processes in tests, use `bunExe` and `bunEnv` from `harness` to ensure the same build of Bun is used and debug logging is silenced

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always use `await using` or `using` to ensure proper resource cleanup in tests for APIs like Bun.listen, Bun.connect, Bun.spawn, Bun.serve, etc

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-18T05:23:24.403Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/telemetry-server.test.ts:91-100
Timestamp: 2025-10-18T05:23:24.403Z
Learning: In the Bun codebase, telemetry tests (test/js/bun/telemetry-*.test.ts) should focus on telemetry API behavior: configure/disable/isEnabled, callback signatures and invocation, request ID correlation, and error handling. HTTP protocol behaviors like status code normalization (e.g., 200 with empty body → 204) should be tested in HTTP server tests (test/js/bun/http/), not in telemetry tests. Keep separation of concerns: telemetry tests verify the telemetry API contract; HTTP tests verify HTTP semantics.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-26T01:32:04.844Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24082
File: test/cli/test/coverage.test.ts:60-112
Timestamp: 2025-10-26T01:32:04.844Z
Learning: In the Bun repository test files (test/cli/test/*.test.ts), when spawning Bun CLI commands with Bun.spawnSync for testing, prefer using stdio: ["inherit", "inherit", "inherit"] to inherit stdio streams rather than piping them.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T04:55:33.099Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: test/js/bun/http/node-telemetry.test.ts:27-203
Timestamp: 2025-10-19T04:55:33.099Z
Learning: In test/js/bun/http/node-telemetry.test.ts and the Bun.telemetry._node_binding API, after the architecture refactor, the _node_binding interface only contains two methods: handleIncomingRequest(req, res) and handleWriteHead(res, statusCode). The handleRequestFinish hook and other lifecycle hooks were removed during simplification. Both current methods are fully tested.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Verify tests fail with `USE_SYSTEM_BUN=1 bun test <file>` and pass with `bun bd test <file>` - tests are invalid if they pass with USE_SYSTEM_BUN=1

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : For multi-file tests, prefer `tempDir` and `Bun.spawn` over single-file tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Use `-e` flag for single-file tests when spawning Bun processes

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-19T02:44:46.354Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 23798
File: packages/bun-otel/context-propagation.test.ts:1-1
Timestamp: 2025-10-19T02:44:46.354Z
Learning: In the Bun repository, standalone packages under packages/ (e.g., bun-vscode, bun-inspector-protocol, bun-plugin-yaml, bun-plugin-svelte, bun-debug-adapter-protocol, bun-otel) co-locate their tests with package source code using *.test.ts files. This follows standard npm/monorepo patterns. The test/ directory hierarchy (test/js/bun/, test/cli/, test/js/node/) is reserved for testing Bun's core runtime APIs and built-in functionality, not standalone packages.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : Do not write flaky tests - do not use `setTimeout` in tests; instead await the condition to be met

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not write flaky tests. Never wait for time to pass in tests; always wait for the condition to be met instead of using an arbitrary amount of time

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-03T01:30:58.001Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 21728
File: test/js/valkey/valkey.test.ts:264-271
Timestamp: 2025-09-03T01:30:58.001Z
Learning: For test/js/valkey/valkey.test.ts PUB/SUB tests, avoid arbitrary sleeps and async-forEach. Instead, resolve a Promise from the subscriber callback when the expected number of messages is observed and await it with a bounded timeout (e.g., withTimeout + Promise.withResolvers) to account for Redis server→subscriber propagation.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to **/*.test.ts?(x) : When spawning processes in tests, expect stdout before expecting exit code for more useful error messages on test failure

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Always check exit codes and test error scenarios in error tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Prefer async/await over callbacks in tests

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:57:56.685Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:268-276
Timestamp: 2025-09-20T00:57:56.685Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods like ctx.redis.set() - the maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-09-20T00:58:38.042Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 22568
File: test/js/valkey/valkey.test.ts:561-564
Timestamp: 2025-09-20T00:58:38.042Z
Learning: For test/js/valkey/valkey.test.ts, do not comment on synchronous throw assertions for async Redis methods (like ctx.redis.set(), ctx.redis.unsubscribe(), etc.) - Bun's Redis client implementation differs from Node.js and can throw synchronously even for async methods. The maintainer has explicitly requested to stop looking at this error pattern.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Do not set a timeout on tests. Bun already has timeouts

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-12-16T00:21:32.179Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-16T00:21:32.179Z
Learning: Applies to test/**/*.test.ts?(x) : Always use `port: 0` in tests - do not hardcode ports or use custom random port number functions

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Never use hardcoded port numbers in tests. Always use `port: 0` to get a random port

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Applies to test/**/*.test.{ts,js,jsx,tsx,mjs,cjs} : Prefer concurrent tests over sequential tests using `test.concurrent` or `describe.concurrent` when multiple tests spawn processes or write files, unless it's very difficult to make them concurrent

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-08T04:06:33.198Z
Learnt from: Jarred-Sumner
Repo: oven-sh/bun PR: 24491
File: test/js/bun/transpiler/declare-global.test.ts:17-17
Timestamp: 2025-11-08T04:06:33.198Z
Learning: In Bun test files, `await using` with Bun.spawn() is the preferred pattern for spawned processes regardless of whether they are short-lived or long-running. Do not suggest replacing `await using proc = Bun.spawn(...)` with `const proc = Bun.spawn(...); await proc.exited;`.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-06T00:58:23.965Z
Learnt from: markovejnovic
Repo: oven-sh/bun PR: 24417
File: test/js/bun/spawn/spawn.test.ts:903-918
Timestamp: 2025-11-06T00:58:23.965Z
Learning: In Bun test files, `await using` with spawn() is appropriate for long-running processes that need guaranteed cleanup on scope exit or when explicitly testing disposal behavior. For short-lived processes that exit naturally (e.g., console.log scripts), the pattern `const proc = spawn(...); await proc.exited;` is standard and more common, as evidenced by 24 instances vs 4 `await using` instances in test/js/bun/spawn/spawn.test.ts.

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-11-24T18:37:30.259Z
Learnt from: CR
Repo: oven-sh/bun PR: 0
File: test/CLAUDE.md:0-0
Timestamp: 2025-11-24T18:37:30.259Z
Learning: Unit tests for specific features are organized by module (e.g., `/test/js/bun/`, `/test/js/node/`)

Applied to files:

  • test/regression/issue/05951.test.ts
📚 Learning: 2025-10-25T17:20:19.041Z
Learnt from: theshadow27
Repo: oven-sh/bun PR: 24063
File: test/js/bun/telemetry/server-header-injection.test.ts:5-20
Timestamp: 2025-10-25T17:20:19.041Z
Learning: In the Bun telemetry codebase, tests are organized into two distinct layers: (1) Internal API tests in test/js/bun/telemetry/ use numeric InstrumentKind enum values to test Zig↔JS injection points and low-level integration; (2) Public API tests in packages/bun-otel/test/ use string InstrumentKind values ("http", "fetch", etc.) to test the public-facing BunSDK and instrumentation APIs. This separation allows internal tests to use efficient numeric enums for refactoring flexibility while the public API maintains a developer-friendly string-based interface.

Applied to files:

  • test/regression/issue/05951.test.ts
🔇 Additional comments (1)
test/regression/issue/05951.test.ts (1)

8-135: Excellent test structure and adherence to guidelines.

The tests in this concurrent suite follow all coding guidelines:

  • Use port: 0 for dynamic port allocation
  • Use await using with Bun.spawn() for automatic resource cleanup
  • Check exit codes with await proc.exited
  • Use the -e flag for inline script tests
  • Collect stderr and exit code with Promise.all for better error messages
  • Avoid arbitrary timeouts, using event-based Promise patterns instead
  • Proper cleanup with finally blocks

The test scenarios comprehensively cover the new upgrade and unexpected-response events functionality.

- All tests now properly indented inside describe block
- Remove redundant comment about concurrency
- Cleaner, more consistent code
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ws.WebSocket 'upgrade' and 'unexpected-response' event is not implemented in bun

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