alow standalone bun executable to use local bun instance in Bun.$

[RiskyMH]

What does this PR do?

Ensures you can always do this, even when in standalone and no bun in path:

await Bun.$`bun --revision`
await Bun.$`bunx cowsay hi`

import { fork } from "child_process";
fork("-p", ["1 + 1"]);

currently it will use same executable if no bun in path, however standalone it just infinite loops because its running itself Now it will always try to use the same bun that started it (including standalone). fixes #16262, fixes #14459, fixes #5414

uses @pfgithub's solution and extends it to be able to use in safer Bun shell

concerns: implies the whole binary will be available forever, so could be harder to minify and remove unneeded parts

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

will need to test with the the CI's release build

[robobun]

^{Updated 6:11 AM PT - Feb 5th, 2025}

❌ @RiskyMH, your commit c225c12 has 5 failures in Build #11130:

• test/integration/next-pages/test/dev-server-ssr-100.test.ts - 1 failing on 🍎 14 aarch64
• test/integration/next-pages/test/dev-server-ssr-100.test.ts - 1 failing on 🍎 13 aarch64
• test/integration/next-pages/test/dev-server-ssr-100.test.ts - 1 failing on 🍎 14 x64
• test/integration/next-pages/test/dev-server-ssr-100.test.ts - 1 failing on 🍎 13 x64
• test/cli/install/bun-install-registry.test.ts - 6 failing on 🪟 2019 x64-baseline
• test/cli/install/bun-install-registry.test.ts - 1 failing on 🪟 2019 x64
• test/cli/run/as-node.test.ts - 10 failing on 🍎 14 aarch64
• test/cli/run/as-node.test.ts - 10 failing on 🍎 13 aarch64
• test/cli/run/as-node.test.ts - 10 failing on 🍎 14 x64
• test/cli/run/as-node.test.ts - 10 failing on 🍎 13 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 2 failing on 🍎 14 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 2 failing on 🍎 14 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 2 failing on 🍎 13 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 2 failing on 🍎 13 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 12 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 20.04 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 22.04 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 3.20 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 24.04 aarch64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 20.04 x64-baseline
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 22.04 x64-baseline
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 12 x64-baseline
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 12 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 24.04 x64-baseline
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 20.04 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 24.04 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 22.04 x64
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 3.20 x64-baseline
• test/cli/install/bun-install-lifecycle-scripts.test.ts - 3 failing on 🐧 3.20 x64
• test/js/node/test/parallel/test-fs-promises-writefile.js - code 1 on 🪟 2019 x64-baseline

---

🧪   try this PR locally:

bunx bun-pr 16829

[Jarred-Sumner]

Seems nice

Needs a test though

[RiskyMH]

Done, i added tests!

Also should bun.$ (for "bun") prefer the current executable, or be right now and prefer PATH and fallback so there is something?

The issue that this is closing wants it for bun install and I was wondering if maybe the user has a Bun but really old, so the standalone now will use it and get all sorts of errors.

[CosmoMyzrailGorynych]

The issue that this is closing wants it for bun install and I was wondering if maybe the user has a Bun but really old, so the standalone now will use it and get all sorts of errors.

My two cents,
In case of a standalone executable, the main use case of exposing bun CLI to the application is making self-contained, self-sufficient packages — useful for proprietary products or those that aim for non-techie people. So my say is that a packaged app should use itself as a bun CLI to eliminate environment inconsistencies.

[RiskyMH]

Makes sense, to simplify I'll just make it always try to use the same executable (otherwise it would just be weird code to check if standalone and do one bit earlier)

and it kinda made sense the way it was written in docs to use same bun

[pfgithub]

Node has a child_process.fork() function to call the node executable and pass it args, it would make sense for it to work in standalone executables

import { fork } from "child_process";

fork("-p", ["1 + 1"]);

In node/bun, that prints 2, but in a standalone executable it loops forever because it's launching the executable

[RiskyMH]

Oh nice, I didn't know about it. Might see if it's simple to add env var there too

[yus-ham]

for minifying, there should be a build config for what parts to be included into executable

[RiskyMH]

Node has a child_process.fork() function to call the node executable and pass it args, it would make sense for it to work in standalone executables

import { fork } from "child_process";

fork("-p", ["1 + 1"]);

In node/bun, that prints 2, but in a standalone executable it loops forever because it's launching the executable

Added support! I'm surprised this child_processes stuff is all in JS 😅

[RiskyMH]

for minifying, there should be a build config for what parts to be included into executable

Yeah, I don't know the plan for that, but its way out of scope for this pr.

I'd think at least initially your suggestion of flag makes most sense (but there has to be some way of bun knowing which parts of bundle to delete - which gets harder with more interconnected stuff).

[RiskyMH]

i just realized about bunx, i think this is also important to support if bun not installed (not as nice as bun x)