bun:test: Introduce optional type parameter to make bun:test matchers type-safe by default
#18511
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Updated 3:00 PM PT - Sep 9th, 2025
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…matcher-types # Conflicts: # test/integration/bun-types/bun-types.test.ts
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Note Other AI code review bot(s) detectedCodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review. WalkthroughUpdates bun:test TypeScript typings with multiple expect/matcher overloads and NoInfer variants, adds documentation on TypeScript type safety, adjusts integration tests and diagnostics to match new typings, adds a JSON fixture and JSON import side effect; no runtime public API signature changes beyond typings and tests. Changes
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✅ Passed checks (2 passed)
✨ Finishing Touches
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⚠️ Outside diff range comments (4)
packages/bun-types/test.d.ts (4)
875-875: Preserve the actual type through .not chains
not: Matchers<unknown>drops the received type and undermines the goal of type-safe matchers by default. This should remainT.- not: Matchers<unknown>; + not: Matchers<T>;
1078-1091: Fix contradictory description for toContainAnyKeysThe block says “at least one” and then “all the provided keys.” It should be “at least one.”
- /** - * Asserts that an `object` contains at least one of the provided keys. - * Asserts that an `object` contains all the provided keys. + /** + * Asserts that an `object` contains at least one of the provided keys.
1797-1846: Alias docs mismatches (toBeCalled, lastCalledWith, nthCalledWith)*Several aliases have incorrect descriptions or @alias targets. These show up in editor hovers and can confuse users.
- /** - * Ensures that a mock function is called an exact number of times. - * @alias toHaveBeenCalled - */ + /** + * Ensures that a mock function has been called. + * @alias toHaveBeenCalled + */ toBeCalled(): void; @@ - /** - * Ensure that a mock function is called with specific arguments. - * @alias toHaveBeenCalledTimes - */ + /** + * Ensures that a mock function is called an exact number of times. + * @alias toHaveBeenCalledTimes + */ toBeCalledTimes(expected: number): void; @@ - /** - * Ensure that a mock function is called with specific arguments for the nth call. - * @alias toHaveBeenCalledWith - */ + /** + * Ensure that a mock function is called with specific arguments for the last call. + * @alias toHaveBeenLastCalledWith + */ lastCalledWith(...expected: unknown[]): void; @@ - /** - * Ensure that a mock function is called with specific arguments for the nth call. - * @alias toHaveBeenCalledWith - */ + /** + * Ensure that a mock function is called with specific arguments for the nth call. + * @alias toHaveBeenNthCalledWith + */ nthCalledWith(n: number, ...expected: unknown[]): void;
1-2343: Add NoInfer declaration to packages/bun-types/test.d.ts
Defines the utility type before its first usage to prevent TS compile errors:declare module "bun:test" { + // Prevents undesired inference for matcher expected types + type NoInfer<T> = [T][T extends any ? 0 : never]; export const test: Test; // … }
♻️ Duplicate comments (1)
test/integration/bun-types/fixture/test.ts (1)
68-68: Clarify that this fixture is type-only to avoid reviewer confusionThis line will fail at runtime, but the file is never executed. A brief comment here prevents future drive-by nits.
Apply:
- expect("hello").toContain("bun"); + // NOTE: This fixture is type-checked only and not executed; runtime correctness is irrelevant here. + expect("hello").toContain("bun");
🧹 Nitpick comments (12)
test/integration/bun-types/fixture/file.json (1)
1-1: Nit: add a trailing newline for consistencyMinor formatting touch-up to keep diffs clean across tools.
test/integration/bun-types/fixture/index.ts (3)
1-2: Prefer JSON import assertion and avoid unconditional side-effects
- Use an import assertion to align with ESM semantics and TS
resolveJsonModule.- Gate the log to avoid noisy output in integration runs.
Apply:
-import fact from "./file.json"; -console.log(fact); +import fact from "./file.json" assert { type: "json" }; +if (process.env.BUN_TEST_DEBUG) console.log(fact);
407-408: Redundant fallback with non-empty array
statuses[Math.floor(Math.random() * statuses.length)]is always defined here;?? 200never triggers. If the intent is illustrative, leave a short comment; otherwise, drop it.- status: statuses[Math.floor(Math.random() * statuses.length)] ?? 200, + status: statuses[Math.floor(Math.random() * statuses.length)],
441-442: Same redundant fallback as aboveMirror the change for consistency.
- status: statuses[Math.floor(Math.random() * statuses.length)] ?? 200, + status: statuses[Math.floor(Math.random() * statuses.length)],docs/test/writing.md (1)
759-832: Docs: add explicit undefined/union examples to address #7390 and #6934Great section. To make the intent concrete, include one undefined and one union example so readers see the exact fixes this PR targets.
### Strict Type Checking by Default @@ expect(str).toBe(42); // ❌ TypeScript error: string vs number }); This helps catch common mistakes where you might accidentally compare values of different types. +// Optional/undefined preserved (regression in older bun-types) +test("undefined handling", () => { + const result: string | undefined = undefined; + expect(result).toEqual(undefined); // ✅ OK: undefined not stripped +}); + ### Relaxed Type Checking with Type Parameters @@ test("useful for dynamic data", () => { const apiResponse: any = { status: "success" }; @@ expect(apiResponse.status).toBe<string>("success"); // ✅ OK }); + +// Unions in parameterized tests (common in test.each) +test("union-friendly", () => { + const expected: string | null = Math.random() > 0.5 ? "ok" : null; + expect(expected).toBe(expected); // ✅ OK: strict but union-safe + expect(expected).toBe<string | null>(expected); // ✅ Opt-out available +});packages/bun-types/test.d.ts (5)
1059-1076: Docs: key-of on unions is intersection; clarify relaxation path
toContainKey<X = T>(expected: NoInfer<keyof X>)useskeyofwhich intersects keys across union members. That’s fine for “strict by default,” but please add a short doc hint that callers can relax via the generic:expect(obj).toContainKey<Foo | Bar>("onlyInFoo").
1093-1126: Docs: grammar and consistency for toContainValueTweak wording and examples; also remove stray “NOT” line marker.
- /** - * Asserts that an `object` contain the provided value. + /** + * Asserts that an `object` contains the provided value. @@ - * The input value must be an object. + * The received value must be an object. @@ - // NOT + // Negative examples
1127-1143: Docs: pluralization for toContainValues- /** - * Asserts that an `object` contain the provided value. + /** + * Asserts that an `object` contains the provided values.
1156-1171: Docs: pluralization for toContainAllValues- /** - * Asserts that an `object` contain all the provided values. + /** + * Asserts that an `object` contains all the provided values.
1171-1172: Docs: pluralization for toContainAnyValues- /** - * Asserts that an `object` contain any provided value. + /** + * Asserts that an `object` contains any of the provided values.test/integration/bun-types/bun-types.test.ts (1)
402-582: Make diagnostics assertions less brittle across TypeScript bumpsHard-coding full diagnostic arrays (including messages) tends to break with minor TS upgrades or fixture shifts. Prefer asserting on stable fields and using partial/containment matching.
Apply a minimal change like this to assert only the invariant parts and keep count checks:
- expect(diagnostics).toEqual([ - { - code: 2769, - line: "fetch.ts:25:32", - message: "No overload matches this call.", - }, - // ... many more exact objects ... - ]); + const expected = [ + { code: 2769, line: "fetch.ts:25:32" }, + { code: 2769, line: "fetch.ts:33:32" }, + { code: 2769, line: "fetch.ts:168:34" }, + { code: 2353, line: "globals.ts:307:5" }, + // ...keep the rest as { code, line } only... + ]; + expect( + diagnostics.map(({ code, line }) => ({ code, line })) + ).toEqual(expected);Alternatively, if you want to allow additional diagnostics but still guard regressions:
- expect(diagnostics).toEqual([...]); + const expectedSubset = [ + expect.objectContaining({ code: 2769, line: "fetch.ts:25:32" }), + // ... + ]; + expect(diagnostics).toEqual(expect.arrayContaining(expectedSubset)); + expect(diagnostics.length).toBe(expectedSubset.length);test/integration/bun-types/fixture/test.ts (1)
160-301: Nice breadth on matcher overload type testsThis suite hits the edge cases we care about (iterables, key constraints, exactness, arity). Consider factoring a tiny helper to reduce repeated
@ts-expect-errorcomment context, but not required.
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📒 Files selected for processing (6)
docs/test/writing.md(1 hunks)packages/bun-types/test.d.ts(66 hunks)test/integration/bun-types/bun-types.test.ts(4 hunks)test/integration/bun-types/fixture/file.json(1 hunks)test/integration/bun-types/fixture/index.ts(3 hunks)test/integration/bun-types/fixture/test.ts(2 hunks)
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📓 Path-based instructions (6)
test/**
📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)
Place all tests under the test/ directory
Files:
test/integration/bun-types/fixture/file.jsontest/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
test/integration/**
📄 CodeRabbit inference engine (test/CLAUDE.md)
Place integration tests under
test/integration/
Files:
test/integration/bun-types/fixture/file.jsontest/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
test/**/*.{js,ts}
📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)
test/**/*.{js,ts}: Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Prefer data-driven tests (e.g., test.each) to reduce boilerplate
Use shared utilities from test/harness.ts where applicable
Files:
test/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
**/*.{js,ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
Format JavaScript/TypeScript files with Prettier (bun run prettier)
Files:
test/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
test/**/*.test.ts
📄 CodeRabbit inference engine (test/CLAUDE.md)
test/**/*.test.ts: Name test files*.test.tsand usebun:test
Do not write flaky tests: never wait for arbitrary time; wait for conditions instead
Never hardcode port numbers in tests; useport: 0to get a random port
When spawning Bun in tests, usebunExe()andbunEnvfromharness
Preferasync/awaitin tests; for a single callback, usePromise.withResolvers()
Do not set explicit test timeouts; rely on Bun’s built-in timeouts
UsetempDir/tempDirWithFilesfromharnessfor temporary files and directories in tests
For large/repetitive strings in tests, preferBuffer.alloc(count, fill).toString()over"A".repeat(count)
Import common test utilities fromharness(e.g.,bunExe,bunEnv,tempDirWithFiles,tmpdirSync, platform checks, GC helpers)
In error tests, assert non-zero exit codes for failing processes and usetoThrowfor synchronous errors
Usedescribeblocks for grouping,describe.eachfor parameterized tests, snapshots withtoMatchSnapshot, and lifecycle hooks (beforeAll,beforeEach,afterEach); track resources for cleanup inafterEach
Useusing/await usingwith Bun resources (e.g., Bun.listen/connect/spawn/serve) to ensure cleanup in tests
Files:
test/integration/bun-types/bun-types.test.ts
test/**/*.test.{ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
test/**/*.test.{ts,tsx}: Test files must be placed under test/ and end with .test.ts or .test.tsx
In tests, always use port: 0; do not hardcode ports or use custom random port functions
In tests, use normalizeBunSnapshot when asserting snapshots
Never write tests that merely assert absence of "panic" or "uncaught exception" in output
Avoid shell commands (e.g., find, grep) in tests; use Bun.Glob and built-ins instead
Prefer snapshot tests over exact stdout equality assertions
Files:
test/integration/bun-types/bun-types.test.ts
🧠 Learnings (20)
📓 Common learnings
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : In tests, use normalizeBunSnapshot when asserting snapshots
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*-fixture.ts : Name test fixture files that are spawned by tests with the suffix `-fixture.ts`
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/bundle.test.ts : bundle.test.ts should contain DevServer-specific bundling tests
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : Prefer snapshot tests over exact stdout equality assertions
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Use `describe` blocks for grouping, `describe.each` for parameterized tests, snapshots with `toMatchSnapshot`, and lifecycle hooks (`beforeAll`, `beforeEach`, `afterEach`); track resources for cleanup in `afterEach`
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Import testing utilities (devTest, prodTest, devAndProductionTest, Dev, Client) from test/bake/bake-harness.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Applied to files:
test/integration/bun-types/fixture/file.jsontest/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Applied to files:
test/integration/bun-types/fixture/file.jsontest/integration/bun-types/fixture/index.tsdocs/test/writing.mdtest/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/bundle.test.ts : bundle.test.ts should contain DevServer-specific bundling tests
Applied to files:
test/integration/bun-types/fixture/index.tstest/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Import testing utilities (devTest, prodTest, devAndProductionTest, Dev, Client) from test/bake/bake-harness.ts
Applied to files:
test/integration/bun-types/fixture/index.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Do not use node:fs APIs in tests; mutate files via dev.write, dev.patch, and dev.delete
Applied to files:
test/integration/bun-types/fixture/index.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Applied to files:
test/integration/bun-types/fixture/index.tsdocs/test/writing.mdtest/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Import common test utilities from `harness` (e.g., `bunExe`, `bunEnv`, `tempDirWithFiles`, `tmpdirSync`, platform checks, GC helpers)
Applied to files:
test/integration/bun-types/fixture/index.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Applied to files:
test/integration/bun-types/fixture/index.tsdocs/test/writing.mdtest/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-08T04:44:59.101Z
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : In tests, use normalizeBunSnapshot when asserting snapshots
Applied to files:
docs/test/writing.mdpackages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-08T04:44:59.101Z
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : Prefer snapshot tests over exact stdout equality assertions
Applied to files:
docs/test/writing.mdpackages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Use `describe` blocks for grouping, `describe.each` for parameterized tests, snapshots with `toMatchSnapshot`, and lifecycle hooks (`beforeAll`, `beforeEach`, `afterEach`); track resources for cleanup in `afterEach`
Applied to files:
docs/test/writing.mdtest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Do not set explicit test timeouts; rely on Bun’s built-in timeouts
Applied to files:
docs/test/writing.md
📚 Learning: 2025-09-08T00:41:12.052Z
Learnt from: CR
PR: oven-sh/bun#0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-09-08T00:41:12.052Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add a corresponding test case in test/v8/v8.test.ts that invokes checkSameOutput with the new function
Applied to files:
test/integration/bun-types/bun-types.test.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/bake-harness.ts : Provide and maintain shared test utilities: devTest, prodTest, devAndProductionTest, Dev, Client, and helpers in the harness
Applied to files:
packages/bun-types/test.d.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : In error tests, assert non-zero exit codes for failing processes and use `toThrow` for synchronous errors
Applied to files:
packages/bun-types/test.d.tstest/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-07T22:26:50.213Z
Learnt from: Jarred-Sumner
PR: oven-sh/bun#22478
File: test/regression/issue/22475.test.ts:0-0
Timestamp: 2025-09-07T22:26:50.213Z
Learning: The `toBeDate()` matcher is acceptable and supported in Bun's test suite - don't suggest replacing it with `toBeInstanceOf(Date)`.
Applied to files:
packages/bun-types/test.d.ts
📚 Learning: 2025-09-07T22:28:28.044Z
Learnt from: Jarred-Sumner
PR: oven-sh/bun#22478
File: test/regression/issue/22475.test.ts:0-0
Timestamp: 2025-09-07T22:28:28.044Z
Learning: toBeDate() is a valid custom matcher available in Bun's test environment and should be used instead of toBeInstanceOf(Date) for Date assertions in Bun tests.
Applied to files:
packages/bun-types/test.d.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Explicitly assert client console logs with c.expectMessage; unasserted logs should not appear
Applied to files:
test/integration/bun-types/fixture/test.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Use shared utilities from test/harness.ts where applicable
Applied to files:
test/integration/bun-types/fixture/test.ts
🧬 Code graph analysis (1)
test/integration/bun-types/fixture/test.ts (2)
packages/bun-types/test.d.ts (4)
expect(575-575)describe(289-289)test(551-551)test(552-552)test/integration/bun-types/fixture/utilities.ts (1)
expectType(35-37)
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🔇 Additional comments (6)
packages/bun-types/test.d.ts (2)
1044-1045: Conditional element type works, but unions may feel too strict
toContain<X = T>(expected: NoInfer<X extends Iterable<infer U> ? U : X>)is solid. Note: forTas a union of iterables, conditional distribution can yield a union of element types, which is acceptable. Just calling out the behavior is intentional.
938-991: Design ACK: generic matchers default to strict, with escape hatch via type parameterThis achieves the PR goal (fixes #6934/#7390) by keeping strictness while allowing opt-out. Nice work.
Also applies to: 1015-1030
test/integration/bun-types/bun-types.test.ts (2)
257-258: LGTM on stronger Set typingAsserting
new Set<string>()is fine here and keeps intent explicit without affecting runtime.
285-286: LGTM on globals checkConsistent with the earlier case; returning an empty Set is the desired invariant.
test/integration/bun-types/fixture/test.ts (2)
55-62: Good use of generic toEqual() to enforce exactnessThese cases clearly exercise both excess-property errors and the “opt-in exact match” behavior.
148-159: Matchers with no actual value: typings look correct
expect().pass()/expect().fail()and the genericexpect<T>()checks exercise the new surface well.
| (actual?: never, customFailMessage?: string): Matchers<undefined>; | ||
| <T = unknown>(actual: T, customFailMessage?: string): Matchers<T>; | ||
| <T = unknown>(actual?: T, customFailMessage?: string): Matchers<T | undefined>; | ||
|
|
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🛠️ Refactor suggestion
Tighten expect() overloads to avoid ambiguity and keep types crisp
The third overload <T = unknown>(actual?: T, ...) overlaps with the first and can weaken expect() by producing Matchers<T | undefined> on zero-arg calls. Two overloads are sufficient and unambiguous.
- (actual?: never, customFailMessage?: string): Matchers<undefined>;
- <T = unknown>(actual: T, customFailMessage?: string): Matchers<T>;
- <T = unknown>(actual?: T, customFailMessage?: string): Matchers<T | undefined>;
+ (): Matchers<undefined>;
+ <T = unknown>(actual: T, customFailMessage?: string): Matchers<T>;📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| (actual?: never, customFailMessage?: string): Matchers<undefined>; | |
| <T = unknown>(actual: T, customFailMessage?: string): Matchers<T>; | |
| <T = unknown>(actual?: T, customFailMessage?: string): Matchers<T | undefined>; | |
| (): Matchers<undefined>; | |
| <T = unknown>(actual: T, customFailMessage?: string): Matchers<T>; |
🤖 Prompt for AI Agents
In packages/bun-types/test.d.ts around lines 586 to 589, the third overload `<T
= unknown>(actual?: T, customFailMessage?: string): Matchers<T | undefined>`
conflicts with the zero-arg overload and weakens typings; remove that third
overload so only two overloads remain: one zero-argument signature returning
Matchers<undefined> and one generic signature taking an actual value and
optional customFailMessage returning Matchers<T>, keeping parameter names and
optional customFailMessage as before to preserve call sites.
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⚠️ Outside diff range comments (2)
test/integration/bun-types/bun-types.test.ts (2)
51-61: Avoid failing the setup when CLAUDE.md is absent
rm CLAUDE.mdwill hard-fail if the file doesn't exist (platform- and CI-dependent). Make it resilient or remove it.bun pm pack --destination ${TEMP_FIXTURE_DIR} - rm CLAUDE.md + rm -f CLAUDE.md mv package.json.backup package.json
402-588: Pin TypeScript to an exact version and relax brittle diagnostics assertions
In test/integration/bun-types/fixture/package.json, change
"typescript": "latest"to a fixed semver (e.g."5.2.4"), disallowing floating tags or range specifiers.In bun-types.test.ts, keep the array length strict but relax each entry’s line and message checks, for example:
- expect(diagnostics).toEqual([ + expect(diagnostics).toHaveLength( /* actual count */ ); + expect(diagnostics).toEqual([ { code: 2769, line: expect.stringMatching(/^fetch\.ts:\d+:\d+$/), message: expect.stringContaining("No overload matches this call"), }, { code: 2353, line: expect.stringMatching(/^globals\.ts:\d+:\d+$/), message: expect.stringContaining("Object literal may only specify known properties"), }, // …apply same pattern to remaining entries… ]);
🧹 Nitpick comments (2)
test/integration/bun-types/bun-types.test.ts (2)
257-257: Prefer size-based assertion for Set emptinessThis improves failure messages and avoids noise from Set diffs.
- expect(emptyInterfaces).toEqual(new Set<string>()); + expect(emptyInterfaces.size).toBe(0);Also applies to: 285-285, 294-294, 370-370, 402-402
294-359: Make diagnostics assertions less brittle for TS message/position driftExact string/position equality here will churn with TS patch updates. Match codes and stabilize message/line with asymmetric matchers.
- expect(diagnostics).toEqual([ - { - "code": 2582, - "line": "my-test.test.ts:2:48", - "message": - "Cannot find name 'test'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.", - }, - { - "code": 2582, - "line": "my-test.test.ts:3:46", - "message": - "Cannot find name 'it'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.", - }, - ... - ]); + expect(diagnostics).toHaveLength(12); + expect(diagnostics).toEqual([ + { + code: 2582, + line: expect.stringMatching(/^my-test\.test\.ts:\d+:\d+$/), + message: expect.stringContaining("Cannot find name 'test'"), + }, + { + code: 2582, + line: expect.stringMatching(/^my-test\.test\.ts:\d+:\d+$/), + message: expect.stringContaining("Cannot find name 'it'"), + }, + // repeat for the remaining entries: keep `code`, relax `line` & `message` + ]);
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test/**
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Place all tests under the test/ directory
Files:
test/integration/bun-types/bun-types.test.ts
test/**/*.{js,ts}
📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)
test/**/*.{js,ts}: Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Prefer data-driven tests (e.g., test.each) to reduce boilerplate
Use shared utilities from test/harness.ts where applicable
Files:
test/integration/bun-types/bun-types.test.ts
test/**/*.test.ts
📄 CodeRabbit inference engine (test/CLAUDE.md)
test/**/*.test.ts: Name test files*.test.tsand usebun:test
Do not write flaky tests: never wait for arbitrary time; wait for conditions instead
Never hardcode port numbers in tests; useport: 0to get a random port
When spawning Bun in tests, usebunExe()andbunEnvfromharness
Preferasync/awaitin tests; for a single callback, usePromise.withResolvers()
Do not set explicit test timeouts; rely on Bun’s built-in timeouts
UsetempDir/tempDirWithFilesfromharnessfor temporary files and directories in tests
For large/repetitive strings in tests, preferBuffer.alloc(count, fill).toString()over"A".repeat(count)
Import common test utilities fromharness(e.g.,bunExe,bunEnv,tempDirWithFiles,tmpdirSync, platform checks, GC helpers)
In error tests, assert non-zero exit codes for failing processes and usetoThrowfor synchronous errors
Usedescribeblocks for grouping,describe.eachfor parameterized tests, snapshots withtoMatchSnapshot, and lifecycle hooks (beforeAll,beforeEach,afterEach); track resources for cleanup inafterEach
Useusing/await usingwith Bun resources (e.g., Bun.listen/connect/spawn/serve) to ensure cleanup in tests
Files:
test/integration/bun-types/bun-types.test.ts
test/integration/**
📄 CodeRabbit inference engine (test/CLAUDE.md)
Place integration tests under
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Files:
test/integration/bun-types/bun-types.test.ts
test/**/*.test.{ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
test/**/*.test.{ts,tsx}: Test files must be placed under test/ and end with .test.ts or .test.tsx
In tests, always use port: 0; do not hardcode ports or use custom random port functions
In tests, use normalizeBunSnapshot when asserting snapshots
Never write tests that merely assert absence of "panic" or "uncaught exception" in output
Avoid shell commands (e.g., find, grep) in tests; use Bun.Glob and built-ins instead
Prefer snapshot tests over exact stdout equality assertions
Files:
test/integration/bun-types/bun-types.test.ts
**/*.{js,ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
Format JavaScript/TypeScript files with Prettier (bun run prettier)
Files:
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🧠 Learnings (6)
📓 Common learnings
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : In tests, use normalizeBunSnapshot when asserting snapshots
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*-fixture.ts : Name test fixture files that are spawned by tests with the suffix `-fixture.ts`
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/bundle.test.ts : bundle.test.ts should contain DevServer-specific bundling tests
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : Prefer snapshot tests over exact stdout equality assertions
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Use `describe` blocks for grouping, `describe.each` for parameterized tests, snapshots with `toMatchSnapshot`, and lifecycle hooks (`beforeAll`, `beforeEach`, `afterEach`); track resources for cleanup in `afterEach`
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Import testing utilities (devTest, prodTest, devAndProductionTest, Dev, Client) from test/bake/bake-harness.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-08T00:41:12.052Z
Learnt from: CR
PR: oven-sh/bun#0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-09-08T00:41:12.052Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add a corresponding test case in test/v8/v8.test.ts that invokes checkSameOutput with the new function
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Applied to files:
test/integration/bun-types/bun-types.test.ts
alii
changed the title
alii
changed the title
bun:test: Introduce optional type parameter to make bun:test matchers type-safe by default
|
Have managed to achieve the same goal without the more significant breaking change (which actually improves the end experience) Of course, some test files might start erroring after this is merged, but in general the errors would actually be useful, and this PR makes it easy to opt out. Developers could also use I think we should merge this soon |
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Actionable comments posted: 0
♻️ Duplicate comments (1)
test/integration/bun-types/fixture/test.ts (1)
68-68: Avoid confusing failing runtime example (fixture isn’t executed).Since this file is type-only, consider making it pass to reduce drive-by comments or add a clarifying note.
- expect("hello").toContain("bun"); + expect("hello bun").toContain("bun");
🧹 Nitpick comments (2)
test/integration/bun-types/fixture/test.ts (1)
306-306: Typo in string literal (“Aswer”).Nip this to keep fixtures clean.
- optionalMethod: input => ({ answer: `Aswer to ${input.question}` }), + optionalMethod: input => ({ answer: `Answer to ${input.question}` }),test/integration/bun-types/bun-types.test.ts (1)
421-589: Diagnostics assertions look correct but are brittle across TS versions.If TS updates, exact messages/lines can churn. Consider asserting on stable fields (code + file:line) and using expect.objectContaining for message.
// Example pattern inside the expect(...).toEqual([...]): expect(diagnostics).toEqual( expect.arrayContaining([ expect.objectContaining({ code: 2345, line: "http.ts:43:24" }), // ...others... ]), );
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packages/bun-types/test.d.ts(66 hunks)test/integration/bun-types/bun-types.test.ts(2 hunks)test/integration/bun-types/fixture/test.ts(3 hunks)
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test/**
📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)
Place all tests under the test/ directory
Files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
test/**/*.{js,ts}
📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)
test/**/*.{js,ts}: Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Prefer data-driven tests (e.g., test.each) to reduce boilerplate
Use shared utilities from test/harness.ts where applicable
Files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
test/integration/**
📄 CodeRabbit inference engine (test/CLAUDE.md)
Place integration tests under
test/integration/
Files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
**/*.{js,ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
Format JavaScript/TypeScript files with Prettier (bun run prettier)
Files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.ts
test/**/*.test.ts
📄 CodeRabbit inference engine (test/CLAUDE.md)
test/**/*.test.ts: Name test files*.test.tsand usebun:test
Do not write flaky tests: never wait for arbitrary time; wait for conditions instead
Never hardcode port numbers in tests; useport: 0to get a random port
When spawning Bun in tests, usebunExe()andbunEnvfromharness
Preferasync/awaitin tests; for a single callback, usePromise.withResolvers()
Do not set explicit test timeouts; rely on Bun’s built-in timeouts
UsetempDir/tempDirWithFilesfromharnessfor temporary files and directories in tests
For large/repetitive strings in tests, preferBuffer.alloc(count, fill).toString()over"A".repeat(count)
Import common test utilities fromharness(e.g.,bunExe,bunEnv,tempDirWithFiles,tmpdirSync, platform checks, GC helpers)
In error tests, assert non-zero exit codes for failing processes and usetoThrowfor synchronous errors
Usedescribeblocks for grouping,describe.eachfor parameterized tests, snapshots withtoMatchSnapshot, and lifecycle hooks (beforeAll,beforeEach,afterEach); track resources for cleanup inafterEach
Useusing/await usingwith Bun resources (e.g., Bun.listen/connect/spawn/serve) to ensure cleanup in tests
Files:
test/integration/bun-types/bun-types.test.ts
test/**/*.test.{ts,tsx}
📄 CodeRabbit inference engine (CLAUDE.md)
test/**/*.test.{ts,tsx}: Test files must be placed under test/ and end with .test.ts or .test.tsx
In tests, always use port: 0; do not hardcode ports or use custom random port functions
In tests, use normalizeBunSnapshot when asserting snapshots
Never write tests that merely assert absence of "panic" or "uncaught exception" in output
Avoid shell commands (e.g., find, grep) in tests; use Bun.Glob and built-ins instead
Prefer snapshot tests over exact stdout equality assertions
Files:
test/integration/bun-types/bun-types.test.ts
🧠 Learnings (17)
📓 Common learnings
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : In tests, use normalizeBunSnapshot when asserting snapshots
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/bundle.test.ts : bundle.test.ts should contain DevServer-specific bundling tests
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Import testing utilities (devTest, prodTest, devAndProductionTest, Dev, Client) from test/bake/bake-harness.ts
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : Prefer snapshot tests over exact stdout equality assertions
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/bake-harness.ts : Provide and maintain shared test utilities: devTest, prodTest, devAndProductionTest, Dev, Client, and helpers in the harness
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Do not set explicit test timeouts; rely on Bun’s built-in timeouts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/**/*.{js,ts} : Write tests in JavaScript or TypeScript using Bun’s Jest-style APIs (test, describe, expect) and run with bun test
Applied to files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Name test files `*.test.ts` and use `bun:test`
Applied to files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-08T04:44:59.101Z
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : Prefer snapshot tests over exact stdout equality assertions
Applied to files:
test/integration/bun-types/fixture/test.tspackages/bun-types/test.d.ts
📚 Learning: 2025-09-08T00:41:12.052Z
Learnt from: CR
PR: oven-sh/bun#0
File: src/bun.js/bindings/v8/CLAUDE.md:0-0
Timestamp: 2025-09-08T00:41:12.052Z
Learning: Applies to src/bun.js/bindings/v8/test/v8/v8.test.ts : Add a corresponding test case in test/v8/v8.test.ts that invokes checkSameOutput with the new function
Applied to files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-08-30T00:12:56.803Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-08-30T00:12:56.803Z
Learning: Applies to test/js/bun/**/*.{js,ts} : Place Bun API tests under test/js/bun/, separated by category (e.g., test/js/bun/glob/)
Applied to files:
test/integration/bun-types/fixture/test.tstest/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Use `describe` blocks for grouping, `describe.each` for parameterized tests, snapshots with `toMatchSnapshot`, and lifecycle hooks (`beforeAll`, `beforeEach`, `afterEach`); track resources for cleanup in `afterEach`
Applied to files:
test/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : In error tests, assert non-zero exit codes for failing processes and use `toThrow` for synchronous errors
Applied to files:
test/integration/bun-types/fixture/test.tspackages/bun-types/test.d.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/{dev/*.test.ts,dev-and-prod.ts} : Explicitly assert client console logs with c.expectMessage; unasserted logs should not appear
Applied to files:
test/integration/bun-types/fixture/test.ts
📚 Learning: 2025-09-08T04:44:59.101Z
Learnt from: CR
PR: oven-sh/bun#0
File: CLAUDE.md:0-0
Timestamp: 2025-09-08T04:44:59.101Z
Learning: Applies to test/**/*.test.{ts,tsx} : In tests, use normalizeBunSnapshot when asserting snapshots
Applied to files:
test/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/bundle.test.ts : bundle.test.ts should contain DevServer-specific bundling tests
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : When spawning Bun in tests, use `bunExe()` and `bunEnv` from `harness`
Applied to files:
test/integration/bun-types/bun-types.test.tspackages/bun-types/test.d.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/dev/ecosystem.test.ts : ecosystem.test.ts should focus on concrete library integration bugs rather than whole-package coverage
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-09-03T17:10:13.486Z
Learnt from: CR
PR: oven-sh/bun#0
File: test/CLAUDE.md:0-0
Timestamp: 2025-09-03T17:10:13.486Z
Learning: Applies to test/**/*.test.ts : Do not set explicit test timeouts; rely on Bun’s built-in timeouts
Applied to files:
test/integration/bun-types/bun-types.test.ts
📚 Learning: 2025-08-30T00:09:39.100Z
Learnt from: CR
PR: oven-sh/bun#0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-08-30T00:09:39.100Z
Learning: Applies to test/bake/bake-harness.ts : Provide and maintain shared test utilities: devTest, prodTest, devAndProductionTest, Dev, Client, and helpers in the harness
Applied to files:
packages/bun-types/test.d.ts
📚 Learning: 2025-09-07T22:26:50.213Z
Learnt from: Jarred-Sumner
PR: oven-sh/bun#22478
File: test/regression/issue/22475.test.ts:0-0
Timestamp: 2025-09-07T22:26:50.213Z
Learning: The `toBeDate()` matcher is acceptable and supported in Bun's test suite - don't suggest replacing it with `toBeInstanceOf(Date)`.
Applied to files:
packages/bun-types/test.d.ts
📚 Learning: 2025-09-07T22:28:28.044Z
Learnt from: Jarred-Sumner
PR: oven-sh/bun#22478
File: test/regression/issue/22475.test.ts:0-0
Timestamp: 2025-09-07T22:28:28.044Z
Learning: toBeDate() is a valid custom matcher available in Bun's test environment and should be used instead of toBeInstanceOf(Date) for Date assertions in Bun tests.
Applied to files:
packages/bun-types/test.d.ts
🧬 Code graph analysis (1)
test/integration/bun-types/fixture/test.ts (2)
packages/bun-types/test.d.ts (3)
expect(575-575)test(551-551)test(552-552)test/integration/bun-types/fixture/utilities.ts (1)
expectType(35-37)
⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)
- GitHub Check: Format
🔇 Additional comments (11)
test/integration/bun-types/fixture/test.ts (4)
55-62: Good negative/positive type-intent checks for toEqual.Covers both the erroring and the exact-match paths well.
148-159: Lock in expect() overload behaviors with one more edge-case check.Add a case to assert generic-only usage without an actual value keeps the intended union shape.
// Additional check suggested near here: expectType(expect<string | null>()).is<import("bun:test").Matchers<string | null | undefined>>();
160-301: Matcher Overload Type Tests are comprehensive and target real pitfalls.Nice coverage of NoInfer-ed variants and error shapes.
340-359: Advanced assignability tests clearly demonstrate opt-in/opt-out behavior.These examples reflect the design goals from #6934 and #7390.
test/integration/bun-types/bun-types.test.ts (1)
123-124: Enforcing skipDefaultLibCheck: false is the right guardrail here.Prevents regressions like #8761 slipping in via lib drift.
packages/bun-types/test.d.ts (6)
586-589: Keep all three expect() overloads; order matters.The third overload enables generic-only calls (e.g., expect() → Matchers<string|undefined>) used by the fixture; the ordering avoids ambiguity with the required-arg overload.
905-918: New expect().fail() matches the extended matcher set and complements pass().API surface looks coherent.
938-940: NoInfer-ed toBe overload is a solid tightening.Prevents accidental widening while allowing explicit opt-out via generic arg.
991-993: NoInfer-ed toEqual overload aligns with #7390 goals (undefined handling).Good balance between safety and escape hatches.
1017-1019: NoInfer-ed toStrictEqual mirrors toEqual correctly.Consistent typing story across equality matchers.
1032-1050: Iterable-aware typings for toBeOneOf/toContain look right; validate symbol-key support at runtime.Keys helpers accept keyof T (includes symbol). Ensure runtime matchers handle symbol keys equivalently.
Fixes #6934
Fixes #7390
This PR also adds a test case for checking matchers, including when they should fail