Add WithBun() support for Vite apps

[emilienbev]

Description

This PR adds native bun support for Vite/JavaScript resources via a new WithBun() extension method, enabling bun install and bun run <script> flows similar to existing WithNpm(), WithYarn(), and WithPnpm() support.

Changes

• Added WithBun() for JavaScriptAppResource-based resources.
• Uses bun executable and run script command (bun run <script> ...).
• Does not inject the -- command separator (bun forwards script flags without it).
• Copies package.json + bun lockfile(s) for Docker layer caching (bun.lock / bun.lockb when present).
• Sets bun cache mount for Dockerfile generation (/root/.bun/install/cache).
• Ensures publish-mode Dockerfile generation can execute bun by overriding the build base image to oven/bun:1 when not already specified (assuming using latest isn't recommended here? Unsure.)

Fixes #13686

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire-docs issue: [Community Toolkit New article]: Add WithBun to Javascript integrations docs-aspire#6091
  • No

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 13733

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 13733"

[Copilot]

Pull request overview

This PR adds native Bun package manager support for JavaScript/Vite applications in Aspire, enabling developers to use bun install and bun run commands similar to existing npm, Yarn, and pnpm support.

Key Changes:

• Introduces a new WithBun() extension method for JavaScript app resources that configures Bun as the package manager
• Implements Bun-specific behavior: no command separator (--) when passing script flags, support for both bun.lock and bun.lockb files, and Docker base image override to oven/bun:1
• Adds comprehensive test coverage for Bun installation arguments and command-line behavior

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
src/Aspire.Hosting.JavaScript/JavaScriptHostingExtensions.cs	Implements WithBun() extension method with Bun-specific configuration including lockfile handling, Docker image override, and install command setup
tests/Aspire.Hosting.JavaScript.Tests/PackageInstallationTests.cs	Adds test verifying Bun uses --frozen-lockfile flag in publish mode
tests/Aspire.Hosting.JavaScript.Tests/AddViteAppWithPnpmTests.cs	Adds test confirming Bun correctly omits command separator when passing script arguments

[emilienbev]

@dotnet-policy-service agree

[davidfowl]

✅ End-to-End Verification Complete

Tested PR locally using dogfood CLI. All scenarios work correctly:

Test Results:

Feature	Result
WithBun() extension method	✅ Works
bun install runs automatically	✅ 173 packages installed in 5.87s
bun run dev executes correctly	✅ Vite started
No -- separator in command args	✅ Confirmed: ["run", "dev", "--port", "54299"]
Package manager annotation set to bun	✅ Resource source shows "bun"
Web frontend accessible	✅ HTTP 200 OK

Console Logs Evidence:

webfrontend-installer:

bun install v1.3.6 (d530ed99)
173 packages installed [5.87s]

webfrontend:

Cmd = bun.exe, Args = ["run", "dev", "--port", "54299"]

The WithBun() feature works as documented - bun is used for both package installation and script execution, with proper argument handling (no -- separator needed).

[IEvangelist]

Looks good to me, we'll - thank you 🙏