### What does this PR do?
### How did you verify your code works?
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
## Summary
- Adds `--metafile-md` CLI option to `bun build` that generates a
markdown visualization of the module graph
- Designed to help Claude and other LLMs analyze bundle composition,
identify bloat, and understand dependency chains
- Reuses existing metafile JSON generation code as a post-processing
step
## Features
The generated markdown includes:
1. **Quick Summary** - Module counts, sizes, ESM/CJS breakdown,
output/input ratio
2. **Largest Input Files** - Sorted by size to identify potential bloat
3. **Entry Point Analysis** - Shows bundle size, exports, CSS bundles,
and bundled modules
4. **Dependency Chains** - Most commonly imported modules and reverse
dependencies
5. **Full Module Graph** - Complete import/export info for each module
6. **Raw Data for Searching** - Grep-friendly markers in code blocks:
- `[MODULE:]`, `[SIZE:]`, `[IMPORT:]`, `[IMPORTED_BY:]`
- `[ENTRY:]`, `[EXTERNAL:]`, `[NODE_MODULES:]`
## Usage
```bash
# Default filename (meta.md)
bun build entry.js --metafile-md --outdir=dist
# Custom filename
bun build entry.js --metafile-md=analysis.md --outdir=dist
# Both JSON and markdown
bun build entry.js --metafile=meta.json --metafile-md=meta.md --outdir=dist
```
## Example Output
See sample output: https://gist.github.com/example (will add)
## Test plan
- [x] Test default filename (`meta.md`)
- [x] Test custom filename
- [x] Test both `--metafile` and `--metafile-md` together
- [x] Test summary metrics
- [x] Test module format info (ESM/CJS)
- [x] Test external imports
- [x] Test exports list
- [x] Test bundled modules table
- [x] Test CSS bundle reference
- [x] Test import kinds (static, dynamic, require)
- [x] Test commonly imported modules
- [x] Test largest files sorting (bloat analysis)
- [x] Test output/input ratio
- [x] Test grep-friendly raw data section
- [x] Test entry point markers
- [x] Test external import markers
- [x] Test node_modules markers
All 17 new tests pass.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
## Summary
Adds a new CLI flag `--compile-executable-path` that allows specifying a
custom Bun executable path for cross-compilation instead of downloading
from the npm registry.
## Usage
```bash
bun build --compile --target=bun-linux-x64 \
--compile-executable-path=/path/to/bun-linux-x64 app.ts
```
## Motivation
The `executablePath` option was already available in the JavaScript
`Bun.build()` API. This exposes the same functionality from the CLI.
## Changes
- Added `--compile-executable-path <STR>` CLI parameter in
`src/cli/Arguments.zig`
- Added `compile_executable_path` field to `BundlerOptions` in
`src/cli.zig`
- Wired the option through to `StandaloneModuleGraph.toExecutable()` in
`src/cli/build_command.zig`
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
- Adds `import { feature } from "bun:bundle"` for compile-time feature
flag checking
- `feature("FLAG_NAME")` calls are replaced with `true`/`false` at
bundle time
- Enables dead-code elimination through `--feature=FLAG_NAME` CLI
argument
- Works in `bun build`, `bun run`, and `bun test`
- Available in both CLI and `Bun.build()` JavaScript API
## Usage
```ts
import { feature } from "bun:bundle";
if (feature("SUPER_SECRET")) {
console.log("Secret feature enabled!");
} else {
console.log("Normal mode");
}
```
### CLI
```bash
# Enable feature during build
bun build --feature=SUPER_SECRET index.ts
# Enable at runtime
bun run --feature=SUPER_SECRET index.ts
# Enable in tests
bun test --feature=SUPER_SECRET
```
### JavaScript API
```ts
await Bun.build({
entrypoints: ['./index.ts'],
outdir: './out',
features: ['SUPER_SECRET', 'ANOTHER_FLAG'],
});
```
## Implementation
- Added `bundler_feature_flags` (as `*const bun.StringSet`) to
`RuntimeFeatures` and `BundleOptions`
- Added `bundler_feature_flag_ref` to Parser struct to track the
`feature` import
- Handle `bun:bundle` import at parse time (similar to macros) - capture
ref, return empty statement
- Handle `feature()` calls in `e_call` visitor - replace with boolean
based on flags
- Wire feature flags through CLI arguments and `Bun.build()` API to
bundler options
- Added `features` option to `JSBundler.zig` for JavaScript API support
- Added TypeScript types in `bun.d.ts`
- Added documentation to `docs/bundler/index.mdx`
## Test plan
- [x] Basic feature flag enabled/disabled tests (both CLI and API
backends)
- [x] Multiple feature flags test
- [x] Dead code elimination verification tests
- [x] Error handling for invalid arguments
- [x] Runtime tests with `bun run --feature=FLAG`
- [x] Test runner tests with `bun test --feature=FLAG`
- [x] Aliased import tests (`import { feature as checkFeature }`)
- [x] Ternary operator DCE tests
- [x] Tests use `itBundled` with both `backend: "cli"` and `backend:
"api"`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Alistair Smith <hi@alistair.sh>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
## Summary
By default, standalone executables no longer load `tsconfig.json` and
`package.json` at runtime. This improves startup performance and
prevents unexpected behavior from config files in the runtime
environment.
- Added `--compile-autoload-tsconfig` / `--no-compile-autoload-tsconfig`
CLI flags (default: false)
- Added `--compile-autoload-package-json` /
`--no-compile-autoload-package-json` CLI flags (default: false)
- Added `autoloadTsconfig` and `autoloadPackageJson` options to the
`Bun.build()` compile config
- Flags are stored in `StandaloneModuleGraph.Flags` and applied at
runtime boot
This follows the same pattern as the existing
`--compile-autoload-dotenv` and `--compile-autoload-bunfig` flags.
## Test plan
- [x] Added tests in `test/bundler/bundler_compile_autoload.test.ts`
- [x] Verified standalone executables work correctly with runtime config
files that differ from compile-time configs
- [x] Verified the new CLI flags are properly parsed and applied
- [x] Verified the JS API options work correctly
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Fixes#19652
## Summary
Fixes a crash that occurred when using the `--production` flag with `bun
build`, particularly on Windows where assertions are enabled in release
builds.
## Root Cause
The crash occurred because an assertion for `jsx.development` was
running **before** `jsx.development` was properly configured. The
problematic sequence was:
1. Set `NODE_ENV=production` in env map
2. Call `configureDefines()` which reads `NODE_ENV` and calls
`setProduction(true)`, setting `jsx.development=false`
3. ❌ **Assert `jsx.development` is false** (assertion fired here, before
line 203 below)
4. Set `jsx.development = !production` on line 203 (too late)
## Changes
This PR reorders the code to move the assertion **after**
`jsx.development` is properly set:
1. Set both `BUN_ENV` and `NODE_ENV` to `"production"` in env map
2. Call `configureDefines()`
3. Set `jsx.development = !production` (now happens first)
4. ✅ **Assert `jsx.development` is false** (now runs after it's set)
Also adds `BUN_ENV=production` to match the behavior of setting
`NODE_ENV`.
## Test Plan
Added regression test in `test/regression/issue/19652.test.ts` that
verifies `bun build --production` doesn't crash.
The test:
- ✅ Passes on this branch
- ❌ Would fail on main (assertion failure)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Fixes#23569
## Summary
HTML imports require bundling to work correctly, as they need to process
and transform linked assets (JS/CSS). When `--no-bundle` is used, no
bundling or transformation happens, which causes a crash.
This change adds validation to detect HTML entrypoints when
`--no-bundle` is used and provides a clear error message explaining that
"HTML imports are only supported when bundling".
## Changes
- Added validation in `src/cli/build_command.zig` to check for HTML
entrypoints when `--no-bundle` flag is used
- Shows clear error message: "HTML imports are only supported when
bundling"
- Added regression tests in `test/regression/issue/23569.test.ts`
## Test Plan
### Before
```bash
$ bun build ./index.html --no-bundle
# Crashes without helpful error
```
### After
```bash
$ bun build ./index.html --no-bundle
error: HTML imports are only supported when bundling
```
### Tests
- ✅ Test with `--no-bundle` flag errors correctly
- ✅ Test with `--no-bundle --outdir` errors correctly
- ✅ Test without `--no-bundle` works normally
- ✅ All 3 regression tests pass
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
- Removes unused function and class expression names when
`--minify-syntax` is enabled during bundling
- Adds `--keep-names` flag to preserve original names when minifying
- Matches esbuild's minification behavior
## Problem
When minifying with `--minify-syntax`, Bun was keeping function and
class expression names even when they were never referenced, resulting
in larger bundle sizes compared to esbuild.
**Before:**
```js
export var AB = function A() { };
// Bun output: var AB = function A() {};
// esbuild output: var AB = function() {};
```
## Solution
This PR adds logic to remove unused function and class expression names
during minification, matching esbuild's behavior. Names are only removed
when:
- `--minify-syntax` is enabled
- Bundling is enabled (not transform-only mode)
- The scope doesn't contain direct eval (which could reference the name
dynamically)
- The symbol's usage count is 0
Additionally, a `--keep-names` flag has been added to preserve original
names when desired (useful for debugging or runtime reflection).
## Testing
- Updated existing test in `bundler_minify.test.ts`
- All transpiler tests pass
- Manually verified output matches esbuild for various cases
## Examples
```bash
# Without --keep-names (names removed)
bun build --minify-syntax input.js
# var AB = function() {}
# With --keep-names (names preserved)
bun build --minify-syntax --keep-names input.js
# var AB = function A() {}
```
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
### What does this PR do?
in the name
### How did you verify your code works?
tests, but using ci to see if anything else broke
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
## Summary
This PR adds a new `--compile-argv` option to `bun build --compile` that
allows developers to embed runtime arguments into standalone
executables. The specified arguments are stored in the executable
metadata during compilation and provide **dual functionality**:
1. **🔧 Actually processed by Bun runtime** (like passing them on command
line)
2. **📊 Available in `process.execArgv`** (for application inspection)
This means flags like `--user-agent`, `--smol`, `--max-memory` will
actually take effect AND be visible to your application!
## Motivation & Use Cases
### 1. **Global User Agent for Web Scraping**
Perfect for @thdxr's opencode use case - the user agent actually gets
applied:
```bash
# Compile with custom user agent that ACTUALLY works
bun build --compile --compile-argv="--user-agent='OpenCode/1.0'" ./scraper.ts --outfile=opencode
# The user agent is applied by Bun runtime AND visible in execArgv
./opencode # All HTTP requests use the custom user agent!
```
### 2. **Memory-Optimized Builds**
Create builds with actual runtime memory optimizations:
```bash
# Compile with memory optimization that ACTUALLY takes effect
bun build --compile --compile-argv="--smol --max-memory=512mb" ./app.ts --outfile=app-optimized
# Bun runtime actually runs in smol mode with memory limit
```
### 3. **Performance & Debug Builds**
Different builds with different runtime characteristics:
```bash
# Production: optimized for memory
bun build --compile --compile-argv="--smol --gc-frequency=high" ./app.ts --outfile=app-prod
# Debug: with inspector enabled
bun build --compile --compile-argv="--inspect=0.0.0.0:9229" ./app.ts --outfile=app-debug
```
### 4. **Security & Network Configuration**
Embed security settings that actually apply:
```bash
# TLS and network settings that work
bun build --compile --compile-argv="--tls-min-version=1.3 --dns-timeout=5000" ./secure-app.ts
```
## How It Works
### Dual Processing Architecture
The implementation provides both behaviors:
```bash
# Compiled with: --compile-argv="--smol --user-agent=Bot/1.0"
./my-app --config=prod.json
```
**What happens:**
1. **🔧 Runtime Processing**: Bun processes `--smol` and
`--user-agent=Bot/1.0` as if passed on command line
2. **📊 Application Access**: Your app can inspect these via
`process.execArgv`
```javascript
// In your compiled application:
// 1. The flags actually took effect:
// - Bun is running in smol mode (--smol processed)
// - All HTTP requests use Bot/1.0 user agent (--user-agent processed)
// 2. You can also inspect what flags were used:
console.log(process.execArgv); // ["--smol", "--user-agent=Bot/1.0"]
console.log(process.argv); // ["./my-app", "--config=prod.json"]
// 3. Your application logic can adapt:
if (process.execArgv.includes("--smol")) {
console.log("Running in memory-optimized mode");
}
```
### Implementation Details
1. **Build Time**: Arguments stored in executable metadata
2. **Runtime Startup**:
- Arguments prepended to actual argv processing (so Bun processes them)
- Arguments also populate `process.execArgv` (so app can inspect them)
3. **Result**: Flags work as if passed on command line + visible to
application
## Example Usage
```bash
# User agent that actually works
bun build --compile --compile-argv="--user-agent='MyBot/1.0'" ./scraper.ts --outfile=scraper
# Memory optimization that actually applies
bun build --compile --compile-argv="--smol --max-memory=256mb" ./microservice.ts --outfile=micro
# Debug build with working inspector
bun build --compile --compile-argv="--inspect=127.0.0.1:9229" ./app.ts --outfile=app-debug
# Multiple working flags
bun build --compile --compile-argv="--smol --user-agent=Bot/1.0 --tls-min-version=1.3" ./secure-scraper.ts
```
## Runtime Verification
```javascript
// Check what runtime flags are active
const hasSmol = process.execArgv.includes("--smol");
const userAgent = process.execArgv.find(arg => arg.startsWith("--user-agent="))?.split("=")[1];
const maxMemory = process.execArgv.find(arg => arg.startsWith("--max-memory="))?.split("=")[1];
console.log("Memory optimized:", hasSmol);
console.log("User agent:", userAgent);
console.log("Memory limit:", maxMemory);
// These flags also actually took effect in the runtime!
```
## Changes Made
### Core Implementation
- **Arguments.zig**: Added `--compile-argv <STR>` flag with validation
- **StandaloneModuleGraph.zig**: Serialization/deserialization for
`compile_argv`
- **build_command.zig**: Pass `compile_argv` to module graph
- **cli.zig**: **Prepend arguments to actual argv processing** (so Bun
processes them)
- **node_process.zig**: **Populate `process.execArgv`** from stored
arguments
- **bun.zig**: Made `appendOptionsEnv()` public for reuse
### Testing
- **expectBundled.ts**: Added `compileArgv` test support
- **compile-argv.test.ts**: Tests verifying dual behavior
## Behavior
### Complete Dual Functionality
```javascript
// With --compile-argv="--smol --user-agent=TestBot/1.0":
// ✅ Runtime flags actually processed by Bun:
// - Memory usage optimized (--smol effect)
// - HTTP requests use TestBot/1.0 user agent (--user-agent effect)
// ✅ Flags visible to application:
process.execArgv // ["--smol", "--user-agent=TestBot/1.0"]
process.argv // ["./app", ...script-args] (unchanged)
```
## Backward Compatibility
- ✅ Purely additive feature - no breaking changes
- ✅ Optional flag - existing behavior unchanged when not used
- ✅ No impact on non-compile builds
## Perfect for @thdxr's Use Case!
```bash
# Compile opencode with working user agent
bun build --compile --compile-argv="--user-agent='OpenCode/1.0'" ./opencode.ts --outfile=opencode
# Results in:
# 1. All HTTP requests actually use OpenCode/1.0 user agent ✨
# 2. process.execArgv contains ["--user-agent=OpenCode/1.0"] for inspection ✨
```
The user agent will actually work in all HTTP requests made by the
compiled executable, not just be visible as metadata!
🚀 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Claude <claude@anthropic.ai>
### What does this PR do?
The `then` function in `transpiler.transform` can cause GC, which means
it can cause the `Transpiler` to become freed, which means that if that
same transpiler is in use by another run on the other thread, it could
have pointers to invalid memory.
Also, `ESMCondition` has unnecesasry memory allocations and there is a
very tiny memory leak in optionsFromLoaders
### How did you verify your code works?
Existing tests
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
