Files
bun.sh/test
Claude Bot 022e1a2993 Improve HTML bundler to respect original script tag location
Instead of always injecting scripts at the end of <body>, the bundler now detects where the original script tags were located (in <head> or <body>) and preserves that placement in the bundled output. This respects developer intent while fixing the confusion where scripts were unexpectedly moved.

**How it works:**
- Tracks which section (head/body) we're currently parsing
- Records the location of the first script tag encountered
- Injects bundled scripts in the same location as the original

**Behavior:**
- Scripts in `<head>` → bundled scripts injected before `</head>`
- Scripts in `<body>` → bundled scripts injected before `</body>`
- No scripts found → defaults to `<body>` (common pattern)
- No body element → falls back to `<head>`

**Changes:**
- Added `script_in_body` and `current_section` tracking to HTMLLoader
- Modified onHeadTag/onBodyTag to track current parsing location
- Updated onTag to detect and record script tag locations
- Modified end tag handlers to inject scripts in original location
- Updated dev server injection logic to respect script location
- Added test for scripts in head to verify both scenarios work

**Test results:**
 20/20 tests pass (119 expect() calls)
 Scripts in body stay in body
 Scripts in head stay in head

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

Co-Authored-By: Claude <noreply@anthropic.com>
2025-10-25 02:01:46 +00:00
..
2025-09-26 03:06:18 -07:00
2025-09-30 05:26:32 -07:00
2025-10-11 18:16:43 -07:00
2025-09-30 05:26:32 -07:00
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.