fix: `$.cwd('.')` no longer throws "undefined" path error #25588

dylan-conway · 2025-12-18T22:58:36Z

Summary

.cwd('.'), .cwd(''), .cwd('./'), and .cwd(undefined) now correctly use process.cwd() instead of throwing No such file or directory: .../undefined
Removed unused defaultCwd variable that was always undefined
Empty string is handled correctly by the Zig code - it joins with the current cwd

Test plan

Added tests for .cwd('.'), .cwd(''), .cwd('./'), .cwd(undefined)
Added test for chaining .cwd(temp_dir).cwd('.') to reset to current directory
Added tests for $.cwd('.') and $.cwd(temp_dir) then $.cwd('.') reset
Verified tests fail with USE_SYSTEM_BUN=1 and pass with bun bd test

🤖 Generated with Claude Code

The `defaultCwd` variable was `undefined`, causing `.cwd('.')` to pass `undefined` to `setCwd()`, which the Zig code converted to the literal string "undefined" and appended to the path. Fix by removing the unused `defaultCwd` variable and using empty string instead. Empty string is handled correctly by the Zig code - it joins with the current cwd, effectively meaning "use process.cwd()". 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>

robobun · 2025-12-18T22:58:46Z

^{Updated 7:39 PM PT - Dec 18th, 2025}

@dylan-conway, your commit 7756307 is building: #33543

coderabbitai · 2025-12-18T23:02:59Z

Walkthrough

Shell cwd handling changed to treat undefined, ".", "", and "./" as an empty-string cwd (current directory) and removed the initial defaultCwd. Tests were added to verify cwd behavior, resets, and interactions with process.cwd().

Changes

Cohort / File(s)	Summary
Shell cwd default handling `src/js/builtins/shell.ts`	Remove `defaultCwd` initialization and replace fallback logic so `cwd` uses `""` when newCwd is `undefined`, `"."`, `""`, or `"./"`, preserving public `cwd` method signatures.
Shell cwd behavior tests `test/js/bun/shell/bunshell.test.ts`	Add tests covering `.cwd('.')`, `.cwd('')`, `.cwd('./')`, `.cwd(undefined)`, `.cwd(temp_dir)` plus reset scenarios and assertions comparing `pwd` output to `process.cwd()` and the temp directory.

Suggested reviewers

nektro

Pre-merge checks

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely identifies the main fix: resolving an error when using `.cwd('.')` in the shell API.
Description check	✅ Passed	The PR description includes both required template sections: a comprehensive summary of changes and a detailed test plan with verification steps.
Linked Issues check	✅ Passed	All code changes directly address the linked issue #25579: fixing `.cwd('.')`, `.cwd('')`, `.cwd('./')`, and `.cwd(undefined)` to use process.cwd() instead of throwing errors, with comprehensive test coverage added.
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing the cwd behavior: modifications to src/js/builtins/shell.ts default handling and new tests in test/js/bun/shell/bunshell.test.ts are scoped to the issue requirements.

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Actionable comments posted: 1

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📒 Files selected for processing (2)

src/js/builtins/shell.ts (2 hunks)
test/js/bun/shell/bunshell.test.ts (1 hunks)

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📓 Path-based instructions (6)

test/**/*.{js,ts,jsx,tsx}

📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)

test/**/*.{js,ts,jsx,tsx}: Write tests as JavaScript and TypeScript files using Jest-style APIs (test, describe, expect) and import from bun:test
Use test.each and data-driven tests to reduce boilerplate when testing multiple similar cases

Files:

test/js/bun/shell/bunshell.test.ts

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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

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/builtins/shell.ts

src/js/{builtins,node,bun,thirdparty,internal}/**/*.ts

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

Builtin functions must include this parameter typing in TypeScript to enable direct method binding in C++

Files:

src/js/builtins/shell.ts

🧠 Learnings (24)

📚 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/js/bun/shell/bunshell.test.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/js/bun/shell/bunshell.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 `tempDir()` from harness to create temporary directories with files for multi-file tests instead of creating files manually

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts
src/js/builtins/shell.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) : Avoid shell commands like `find` or `grep` in tests - use Bun's Glob and built-in tools instead

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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 `bun:test` with files that end in `*.test.{ts,js,jsx,tsx,mjs,cjs}`

Applied to files:

test/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:50.422Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:50.422Z
Learning: Applies to test/cli/**/*.{js,ts,jsx,tsx} : When testing Bun as a CLI, use the `spawn` API from `bun` with the `bunExe()` and `bunEnv` from `harness` to execute Bun commands and validate exit codes, stdout, and stderr

Applied to files:

test/js/bun/shell/bunshell.test.ts
src/js/builtins/shell.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/js/bun/shell/bunshell.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 single-file tests, prefer `-e` flag over `tempDir`

Applied to files:

test/js/bun/shell/bunshell.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 `tempDir` from `harness` to create temporary directories - do not use `tmpdirSync` or `fs.mkdtempSync`

Applied to files:

test/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:50.422Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:50.422Z
Learning: Tests should be located in the `test/` directory, organized by category: `cli/` for CLI tests, `js/` for JavaScript/TypeScript tests (further subdivided into `bun/`, `node/`, `web/`, `third_party/`), `napi/` for N-API tests, `v8/` for V8 C++ API tests, `bundler/` for bundler/transpiler tests, and `regression/issue/[number]` for regression tests

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

📚 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: Applies to src/js/{builtins,node,bun,thirdparty,internal}/**/*.{ts,js} : Export modules using `export default { ... }` syntax; modules are NOT ES modules

Applied to files:

src/js/builtins/shell.ts

📚 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: Applies to src/js/{builtins,node,bun,thirdparty,internal}/**/*.{ts,js} : Use private globals and methods with `$` prefix (e.g., `$Array`, `map.$set()`) instead of public JavaScript globals

Applied to files:

src/js/builtins/shell.ts

📚 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: Applies to src/js/{builtins,node,bun,thirdparty,internal}/**/*.{ts,js} : Use `process.platform` and `process.arch` for platform detection; these values are inlined and dead-code eliminated at build time

Applied to files:

src/js/builtins/shell.ts

📚 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: Applies to 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

Applied to files:

src/js/builtins/shell.ts

📚 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/builtins/shell.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:

src/js/builtins/shell.ts

📚 Learning: 2025-11-24T18:37:47.899Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: src/bun.js/bindings/v8/AGENTS.md:0-0
Timestamp: 2025-11-24T18:37:47.899Z
Learning: Applies to src/bun.js/bindings/v8/**/<UNKNOWN> : <UNKNOWN>

Applied to files:

src/js/builtins/shell.ts

🧬 Code graph analysis (1)

test/js/bun/shell/bunshell.test.ts (2)

scripts/utils.mjs (1)

$ (143-161)

test/js/node/util/parse_args/default-args.test.mjs (1)

temp_dir (9-9)

🔇 Additional comments (5)

src/js/builtins/shell.ts (2)

149-156: LGTM! Clear normalization logic for current directory representations.

The normalization of ., ./, "", and undefined to an empty string is correct and addresses the issue where these values previously resulted in "undefined" path errors. The empty string is then passed to the Zig layer via setCwd(""), which correctly interprets it as "use process.cwd()".

276-288: Verify consistent behavior between instance and global cwd handling.

The normalization logic here is correct, but note that when $.cwd('.') is called, it sets cwdSymbol to "". Later, when creating a shell command (lines 310, 330), the check if (cwd) evaluates to false (empty string is falsy), so setCwd is NOT called.

This differs from the instance method ShellPromise.cwd() which explicitly calls setCwd(""). Both code paths should work correctly if:

Not calling setCwd defaults to process.cwd()

Calling setCwd("") explicitly uses process.cwd()

The tests verify this behavior works, including the reset scenario ($.cwd(temp_dir) then $.cwd('.') to reset). However, this subtle difference in implementation could be confusing.

Consider adding a comment explaining that empty string in cwdSymbol is intentionally falsy to skip the setCwd call, relying on default behavior.

Based on learnings, uses process.platform for platform detection which gets inlined at build time.

test/js/bun/shell/bunshell.test.ts (3)

810-816: LGTM! Good test coverage for cwd reset behavior.

This test correctly verifies that calling .cwd('.') after .cwd(temp_dir) resets to the current working directory. This is an important edge case that confirms the fix works for chained calls.

818-822: LGTM! Verifies global cwd setter behavior.

This test correctly verifies that $.cwd('.') sets the default cwd to the current working directory for subsequent commands.

824-837: LGTM! Proper cleanup of global state.

This test correctly verifies the reset behavior when using the global $.cwd() setter. The test properly cleans up by resetting to process.cwd() at the end (lines 834-836), which prevents interference with other tests.

Since this test modifies global state ($.cwd()), it's important that it doesn't run concurrently with other tests. This appears safe as the surrounding describe("cd & pwd") block doesn't use describe.concurrent.

As per coding guidelines, when tests modify shared state, avoid test.concurrent unless the tests are properly isolated.

coderabbitai · 2025-12-18T23:03:02Z

test/js/bun/shell/bunshell.test.ts

+    test(".cwd('.') uses current working directory", async () => {
+      const result = await $`pwd`.cwd(".").text();
+      expect(result.trim()).toBe(process.cwd());
+    });
+
+    test(".cwd('') uses current working directory", async () => {
+      const result = await $`pwd`.cwd("").text();
+      expect(result.trim()).toBe(process.cwd());
+    });
+
+    test(".cwd('./') uses current working directory", async () => {
+      const result = await $`pwd`.cwd("./").text();
+      expect(result.trim()).toBe(process.cwd());
+    });
+
+    test(".cwd(undefined) uses current working directory", async () => {
+      const result = await $`pwd`.cwd(undefined).text();
+      expect(result.trim()).toBe(process.cwd());
+    });


🧹 Nitpick | 🔵 Trivial

Consider using test.each to reduce test duplication.

These four tests follow an identical pattern and could be consolidated using test.each for better maintainability:

Suggested refactor

- test(".cwd('.') uses current working directory", async () => { - const result = await $`pwd`.cwd(".").text(); - expect(result.trim()).toBe(process.cwd()); - }); - - test(".cwd('') uses current working directory", async () => { - const result = await $`pwd`.cwd("").text(); - expect(result.trim()).toBe(process.cwd()); - }); - - test(".cwd('./') uses current working directory", async () => { - const result = await $`pwd`.cwd("./").text(); - expect(result.trim()).toBe(process.cwd()); - }); - - test(".cwd(undefined) uses current working directory", async () => { - const result = await $`pwd`.cwd(undefined).text(); - expect(result.trim()).toBe(process.cwd()); - }); + test.each([ + { value: ".", description: "'.'" }, + { value: "", description: "''" }, + { value: "./", description: "'./'" }, + { value: undefined, description: "undefined" }, + ])(".cwd($description) uses current working directory", async ({ value }) => { + const result = await $`pwd`.cwd(value).text(); + expect(result.trim()).toBe(process.cwd()); + });

As per coding guidelines, use test.each and data-driven tests to reduce boilerplate when testing multiple similar cases.

📝 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.

Suggested change

test(".cwd('.') uses current working directory", async () => {

const result = await $`pwd`.cwd(".").text();

expect(result.trim()).toBe(process.cwd());

});

test(".cwd('') uses current working directory", async () => {

const result = await $`pwd`.cwd("").text();

expect(result.trim()).toBe(process.cwd());

});

test(".cwd('./') uses current working directory", async () => {

const result = await $`pwd`.cwd("./").text();

expect(result.trim()).toBe(process.cwd());

});

test(".cwd(undefined) uses current working directory", async () => {

const result = await $`pwd`.cwd(undefined).text();

expect(result.trim()).toBe(process.cwd());

});

test.each([

{ value: ".", description: "'.'" },

{ value: "", description: "''" },

{ value: "./", description: "'./'" },

{ value: undefined, description: "undefined" },

])(".cwd($description) uses current working directory", async ({ value }) => {

const result = await $`pwd`.cwd(value).text();

expect(result.trim()).toBe(process.cwd());

});

🤖 Prompt for AI Agents

In test/js/bun/shell/bunshell.test.ts around lines 790 to 808, four nearly identical tests verify that different cwd inputs resolve to the current working directory; replace them with a single data-driven test using test.each with the inputs [".", "", "./", undefined] so the same assertion runs for each value, calling $`pwd`.cwd(input).text(), trimming the result and expecting it to equal process.cwd(); ensure the test name includes the parameter for clarity and maintain existing async handling.

coderabbitai

Actionable comments posted: 1

♻️ Duplicate comments (1)

test/js/bun/shell/bunshell.test.ts (1)

790-809: Consider using test.each to reduce test duplication.

These four tests follow an identical pattern and could be consolidated using test.each for better maintainability, as suggested in the previous review.

As per coding guidelines, use test.each and data-driven tests to reduce boilerplate when testing multiple similar cases.

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🧰 Additional context used

📓 Path-based instructions (4)

test/**/*.{js,ts,jsx,tsx}

📄 CodeRabbit inference engine (.cursor/rules/writing-tests.mdc)

test/**/*.{js,ts,jsx,tsx}: Write tests as JavaScript and TypeScript files using Jest-style APIs (test, describe, expect) and import from bun:test
Use test.each and data-driven tests to reduce boilerplate when testing multiple similar cases

Files:

test/js/bun/shell/bunshell.test.ts

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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

🧠 Learnings (21)

📓 Common learnings

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 `tempDir()` from harness to create temporary directories with files for multi-file tests instead of creating files manually

📚 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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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 `tempDir()` from harness to create temporary directories with files for multi-file tests instead of creating files manually

Applied to files:

test/js/bun/shell/bunshell.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) : Avoid shell commands like `find` or `grep` in tests - use Bun's Glob and built-in tools instead

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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 `bun:test` with files that end in `*.test.{ts,js,jsx,tsx,mjs,cjs}`

Applied to files:

test/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:50.422Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:50.422Z
Learning: Applies to test/cli/**/*.{js,ts,jsx,tsx} : When testing Bun as a CLI, use the `spawn` API from `bun` with the `bunExe()` and `bunEnv` from `harness` to execute Bun commands and validate exit codes, stdout, and stderr

Applied to files:

test/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:39.205Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/registering-bun-modules.mdc:0-0
Timestamp: 2025-11-24T18:35:39.205Z
Learning: Add tests for new Bun runtime functionality

Applied to files:

test/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:50.422Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:50.422Z
Learning: Applies to test/**/*.{js,ts,jsx,tsx} : Use `test.each` and data-driven tests to reduce boilerplate when testing multiple similar cases

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-07T17:28:51.204Z

Learnt from: markovejnovic
Repo: oven-sh/bun PR: 24423
File: test/js/node/path/browserify.test.js:472-475
Timestamp: 2025-11-07T17:28:51.204Z
Learning: In test files under test/js/node/path/, markovejnovic prefers functional programming patterns (e.g., reduce, map, filter chains) over imperative loops for clarity and readability.

Applied to files:

test/js/bun/shell/bunshell.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 single-file tests, prefer `-e` flag over `tempDir`

Applied to files:

test/js/bun/shell/bunshell.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 `tempDir` from `harness` to create temporary directories - do not use `tmpdirSync` or `fs.mkdtempSync`

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:50.422Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/writing-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:50.422Z
Learning: Tests should be located in the `test/` directory, organized by category: `cli/` for CLI tests, `js/` for JavaScript/TypeScript tests (further subdivided into `bun/`, `node/`, `web/`, `third_party/`), `napi/` for N-API tests, `v8/` for V8 C++ API tests, `bundler/` for bundler/transpiler tests, and `regression/issue/[number]` for regression tests

Applied to files:

test/js/bun/shell/bunshell.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/js/bun/shell/bunshell.test.ts

📚 Learning: 2025-11-24T18:35:08.612Z

Learnt from: CR
Repo: oven-sh/bun PR: 0
File: .cursor/rules/dev-server-tests.mdc:0-0
Timestamp: 2025-11-24T18:35:08.612Z
Learning: Applies to test/bake/dev/esm.test.ts : Organize ESM tests in esm.test.ts for tests about various ESM features in development mode

Applied to files:

test/js/bun/shell/bunshell.test.ts

🧬 Code graph analysis (1)

test/js/bun/shell/bunshell.test.ts (2)

scripts/utils.mjs (1)

$ (143-161)

test/js/node/util/parse_args/default-args.test.mjs (1)

temp_dir (9-9)

🔇 Additional comments (2)

test/js/bun/shell/bunshell.test.ts (2)

811-817: LGTM!

The chaining behavior test correctly verifies that .cwd(temp_dir).cwd('.') resets to the current working directory.

825-838: LGTM!

Excellent test with proper cleanup. The test correctly verifies the reset behavior and includes explicit cleanup to maintain test isolation, with a final assertion confirming the reset worked.

coderabbitai · 2025-12-19T03:42:28Z

test/js/bun/shell/bunshell.test.ts

+    test("$.cwd('.') sets default cwd to current working directory", async () => {
+      $.cwd(".");
+      const result = await $`pwd`.text();
+      expect(result.trim()).toBe(process.cwd());
+    });


⚠️ Potential issue | 🟠 Major

Potential test isolation issue: Global state not reset.

This test modifies the global $.cwd('.') but doesn't restore it afterward. If other tests depend on the initial $.cwd(process.cwd().replaceAll("\\", "https://github.com/")) set at line 34, they may fail when run after this test.

Consider adding cleanup to restore the original cwd state after the assertion.

🔎 Suggested fix

test("$.cwd('.') sets default cwd to current working directory", async () => { $.cwd("."); const result = await $`pwd`.text(); expect(result.trim()).toBe(process.cwd()); + // Reset to original cwd for test isolation + $.cwd(process.cwd().replaceAll("\\", "https://github.com/")); });

📝 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.

Suggested change

test("$.cwd('.') sets default cwd to current working directory", async () => {

$.cwd(".");

const result = await $`pwd`.text();

expect(result.trim()).toBe(process.cwd());

});

test("$.cwd('.') sets default cwd to current working directory", async () => {

$.cwd(".");

const result = await $`pwd`.text();

expect(result.trim()).toBe(process.cwd());

// Reset to original cwd for test isolation

$.cwd(process.cwd().replaceAll("\\", "https://github.com/"));

});

🤖 Prompt for AI Agents

In test/js/bun/shell/bunshell.test.ts around lines 819 to 823, the test mutates global $.cwd('.') without restoring it; save the current value (the original $.cwd or process.cwd().replaceAll("\\", "https://github.com/") as used at line 34) before calling $.cwd("."), run the assertion, then restore the saved value in a finally block (or use afterEach to reset) so global cwd state is returned to its original value for subsequent tests.

github-actions bot added the claude label Dec 18, 2025

dylan-conway changed the title ~~fix: $\...\.cwd('.') no longer throws "undefined" path error~~ fix: $\pwd\.cwd('.') no longer throws "undefined" path error Dec 18, 2025

dylan-conway changed the title ~~fix: $\pwd\.cwd('.') no longer throws "undefined" path error~~ fix: $pwd.cwd('.') no longer throws "undefined" path error Dec 18, 2025

dylan-conway changed the title ~~fix: $pwd.cwd('.') no longer throws "undefined" path error~~ fix: $pwd.cwd('.') no longer throws "undefined" path error Dec 18, 2025

dylan-conway changed the title ~~fix: $pwd.cwd('.') no longer throws "undefined" path error~~ fix: $.cwd('.') no longer throws "undefined" path error Dec 18, 2025

coderabbitai bot reviewed Dec 18, 2025

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fix: `$.cwd('.')` no longer throws "undefined" path error #25588

fix: `$.cwd('.')` no longer throws "undefined" path error #25588

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fix: $.cwd('.') no longer throws "undefined" path error #25588

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fix: $.cwd('.') no longer throws "undefined" path error #25588

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fix: `$.cwd('.')` no longer throws "undefined" path error #25588

fix: `$.cwd('.')` no longer throws "undefined" path error #25588

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