Files
bun.sh/test
Dylan Conway 4c492c66b8 fix(bundler): fix --compile with 8+ embedded files (#25859)
## Summary

Fixes #20821

When `bun build --compile` was used with 8 or more embedded files, the
compiled binary would silently fail to execute any code (exit code 0, no
output).

**Root cause:** Chunks were sorted alphabetically by their `entry_bits`
key bytes. For entry point 0, the key starts with bit 0 set (byte
pattern `0x01`), but for entry point 8, the key has bit 8 set in the
byte (pattern `0x00, 0x01`). Alphabetically, `0x00 < 0x01`, so entry
point 8's chunk sorted before entry point 0.

This caused the wrong entry point to be identified as the main entry,
resulting in asset wrapper code being executed instead of the user's
code.

**Fix:** Custom sort that ensures `entry_point_id=0` (the main entry
point) always sorts first, with remaining chunks sorted alphabetically
for determinism.

## Test plan

- Added regression test `compile/ManyEmbeddedFiles` that embeds 8 files
and verifies the main entry point runs correctly
- Verified manually with reproduction case from issue

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude <noreply@anthropic.com>
2026-01-06 23:05:01 +00:00
..
2026-01-05 17:21:34 +00:00
2025-09-30 05:26:32 -07:00

Tests

Finding tests

Tests are located in the test/ directory and are organized using the following structure:

  • test/
    • js/ - tests for JavaScript APIs.
    • cli/ - tests for commands, configs, and stdout.
    • bundler/ - tests for the transpiler/bundler.
    • regression/ - tests that reproduce a specific issue.
    • harness.ts - utility functions that can be imported from any test.

The tests in test/js/ directory are further categorized by the type of API.

  • test/js/
    • bun/ - tests for Bun-specific APIs.
    • node/ - tests for Node.js APIs.
    • web/ - tests for Web APIs, like fetch().
    • first_party/ - tests for npm packages that are built-in, like undici.
    • third_party/ - tests for npm packages that are not built-in, but are popular, like esbuild.

Running tests

To run a test, use Bun's built-in test command: bun test.

bun test # Run all tests
bun test js/bun # Only run tests in a directory
bun test sqlite.test.ts # Only run a specific test

If you encounter lots of errors, try running bun install, then trying again.

Writing tests

Tests are written in TypeScript (preferred) or JavaScript using Jest's describe(), test(), and expect() APIs.

import { describe, test, expect } from "bun:test";
import { gcTick } from "harness";

describe("TextEncoder", () => {
  test("can encode a string", async () => {
    const encoder = new TextEncoder();
    const actual = encoder.encode("bun");
    await gcTick();
    expect(actual).toBe(new Uint8Array([0x62, 0x75, 0x6E]));
  });
});

If you are fixing a bug that was reported from a GitHub issue, remember to add a test in the test/regression/ directory.

// test/regression/issue/02005.test.ts

import { it, expect } from "bun:test";

it("regex literal should work with non-latin1", () => {
  const text = "这是一段要替换的文字";
  expect(text.replace(new RegExp("要替换"), "")).toBe("这是一段的文字");
  expect(text.replace(/要替换/, "")).toBe("这是一段的文字");
});

In the future, a bot will automatically close or re-open issues when a regression is detected or resolved.

Zig tests

These tests live in various .zig files throughout Bun's codebase, leveraging Zig's builtin test keyword.

Currently, they're not run automatically nor is there a simple way to run all of them. We will make this better soon.

TypeScript

Test files should be written in TypeScript. The types in packages/bun-types should be updated to support all new APIs. Changes to the .d.ts files in packages/bun-types will be immediately reflected in test files; no build step is necessary.

Writing a test will often require using invalid syntax, e.g. when checking for errors when an invalid input is passed to a function. TypeScript provides a number of escape hatches here.

  • // @ts-expect-error - This should be your first choice. It tells TypeScript that the next line should fail typechecking.
  • // @ts-ignore - Ignore the next line entirely.
  • // @ts-nocheck - Put this at the top of the file to disable typechecking on the entire file. Useful for autogenerated test files, or when ignoring/disabling type checks an a per-line basis is too onerous.