fix: use native Windows ARM64 binary for Bun >= 1.3.10 by oddrationale · Pull Request #165 · oven-sh/setup-bun

oddrationale · 2026-02-26T20:08:14Z

Summary

Use native bun-windows-aarch64.zip on Windows ARM64 runners when Bun version is >= 1.3.10
Preserve the existing x64 baseline fallback for older versions that lack ARM64 assets
Non-semver versions like canary are treated as latest and use native ARM64
Add version-aware hasNativeWindowsArm64() helper using the existing compare-versions dependency

Closes #164

Changes

src/utils.ts — Added hasNativeWindowsArm64() predicate; made getArchitecture() and getAvx2() version-aware with an optional version parameter (backward-compatible)
src/download-url.ts — Passes the resolved version tag to getArchitecture() and getAvx2()
tests/utils.spec.ts — Tests for hasNativeWindowsArm64, updated getArchitecture/getAvx2 tests for version-aware behavior
tests/download-url.spec.ts — Added Windows ARM64 URL tests (native aarch64 for >= 1.3.10, x64-baseline fallback for older, canary native, dynamic version resolution)
dist/ — Rebuilt bundled action

Behavior

Scenario	Result
Windows ARM64 + Bun >= 1.3.10	`bun-windows-aarch64.zip`
Windows ARM64 + Bun < 1.3.10	`bun-windows-x64-baseline.zip` (with warning)
Windows ARM64 + canary	`bun-windows-aarch64.zip`
All other platforms	Unchanged

Test plan

Verify windows-11-arm runner with bun-version: 1.3.10 downloads bun-windows-aarch64.zip
Verify windows-11-arm runner with an older bun-version falls back to bun-windows-x64-baseline.zip
Verify non-Windows and non-ARM64 platforms are unaffected
All 58 unit tests pass (bun test)

🤖 Generated with Claude Code

Bun v1.3.10 ships native Windows ARM64 binaries. Update getArchitecture() and getAvx2() to be version-aware so that windows-11-arm runners download bun-windows-aarch64.zip instead of falling back to bun-windows-x64-baseline.zip. The x64 fallback is preserved for older versions that lack ARM64 assets. Closes #164 Co-Authored-By: Claude Opus 4.6 <[email protected]>

coderabbitai · 2026-02-26T20:16:43Z

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📥 Commits

Reviewing files that changed from the base of the PR and between ab8cb4e and 782c6a3.

⛔ Files ignored due to path filters (1)

dist/setup/index.js is excluded by !**/dist/**

📒 Files selected for processing (5)

.github/workflows/test.yml
src/download-url.ts
src/utils.ts
tests/download-url.spec.ts
tests/utils.spec.ts

Walkthrough

This PR adds version-aware Windows ARM64 native binary support for Bun. It introduces a function to detect if a version ships native ARM64 binaries, updates architecture and AVX2 decision logic to accept version parameters, and expands test coverage for multiple Bun versions on Windows ARM64 hardware.

Changes

Cohort / File(s)	Summary
CI Configuration `.github/workflows/test.yml`	Adds Bun v1.3.10 to the version matrix for test coverage expansion.
Core Utilities `src/utils.ts`, `src/download-url.ts`	Introduces `hasNativeWindowsArm64(version?)` function to determine native ARM64 availability per Bun version. Updates `getArchitecture()` and `getAvx2()` signatures to accept optional version parameter for version-aware Windows ARM64 fallback logic. `download-url.ts` now passes resolved tag consistently to these functions.
Test Suite `tests/utils.spec.ts`, `tests/download-url.spec.ts`	Expands test coverage for Windows ARM64 scenarios across Bun versions (1.3.9, 1.3.10, 1.4.0). Adds test branches for native ARM64 binary usage vs. x64 fallback based on version availability and validates dynamic version resolution with updated API call expectations.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically summarizes the main change: enabling native Windows ARM64 binary usage for Bun versions >= 1.3.10, which aligns with the primary objective of the pull request.
Description check	✅ Passed	The description is comprehensive and directly related to the changeset, explaining the behavior changes, implementation approach, modified files, and test plan.
Linked Issues check	✅ Passed	The pull request fully addresses issue `#164` by implementing version-aware Windows ARM64 support: using native aarch64 binaries for Bun >= 1.3.10, preserving x64 fallback for older versions, and treating non-semver versions as latest.
Out of Scope Changes check	✅ Passed	All code changes are directly related to the Windows ARM64 native binary support objective. The workflow test matrix addition is a supporting change to ensure the new version is tested.

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oddrationale · 2026-02-26T20:34:33Z

Potentially a duplicate of #163. Feel free to close if the other implementation is preferred.

Copilot

Pull request overview

This PR adds support for native Windows ARM64 binaries in Bun versions >= 1.3.10, while maintaining backward compatibility with older versions that only support x64 emulation on Windows ARM64 runners. The implementation uses version comparison to determine whether to download the native bun-windows-aarch64.zip or fall back to bun-windows-x64-baseline.zip.

Changes:

Added version-aware architecture and AVX2 detection for Windows ARM64 platforms
Introduced hasNativeWindowsArm64() helper function to determine if a Bun version supports native Windows ARM64
Updated warning messages to recommend upgrading to Bun >= 1.3.10 for native ARM64 support

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/utils.ts	Added `hasNativeWindowsArm64()` function and made `getArchitecture()` and `getAvx2()` version-aware with optional version parameter
src/download-url.ts	Updated to pass resolved version tag to architecture and AVX2 detection functions
tests/utils.spec.ts	Added comprehensive tests for `hasNativeWindowsArm64()` and updated tests for version-aware behavior in `getArchitecture()` and `getAvx2()`
tests/download-url.spec.ts	Added Windows ARM64 test cases covering native binaries, fallback behavior, and dynamic version resolution
.github/workflows/test.yml	Added Bun v1.3.10 to the test matrix to verify native ARM64 support

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Copilot · 2026-02-26T21:12:33Z

src/utils.ts

+  // Workaround for absence of arm64 builds on Windows before 1.3.10 (#130)
  if (os === "windows" && (arch === "aarch64" || arch === "arm64")) {
-    return false;
+    if (!hasNativeWindowsArm64(version)) {
+      return false;
+    }
+    // Native ARM64 builds don't use AVX2 suffix
+    return true;
  }


The getAvx2 function ignores the user-provided avx2 parameter when Windows ARM64 has native support (>= 1.3.10). While this is likely intentional since ARM64 doesn't support AVX2, it would be good to add test coverage for this behavior to ensure that when a user explicitly sets avx2: false for Windows ARM64 >= 1.3.10, the function still returns true (to avoid adding the -baseline suffix for native ARM64 binaries).

xhyrom · 2026-02-26T21:21:26Z

thanks!

oddrationale · 2026-02-26T22:48:09Z

@xhyrom, thank you for reviewing and merging my contribution. Please don't forget to cut a new release or move the v2 tag. Thanks!

oddrationale force-pushed the fix/windows-arm64-native branch from deba6d4 to 782c6a3 Compare February 26, 2026 20:12

oddrationale marked this pull request as ready for review February 26, 2026 20:13

xhyrom requested review from Copilot and xhyrom and removed request for Copilot February 26, 2026 21:07

Copilot started reviewing on behalf of xhyrom February 26, 2026 21:09 View session

xhyrom mentioned this pull request Feb 26, 2026

refactor: simplify baseline version check, add native windows arm64 build #163

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Copilot AI reviewed Feb 26, 2026

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xhyrom merged commit 0ff83bf into oven-sh:main Feb 26, 2026
91 checks passed

oddrationale mentioned this pull request Feb 26, 2026

Support Windows ARM64 oven-sh/bun#9824

Closed

oddrationale deleted the fix/windows-arm64-native branch February 26, 2026 22:24

oddrationale mentioned this pull request Feb 27, 2026

Enable Windows ARM64 builds in CI cjpais/Handy#340

Merged

duncanmak mentioned this pull request Mar 4, 2026

Downloading x64 version on arm64 Windows runners #168

Closed

oddrationale mentioned this pull request Mar 5, 2026

fix(ci): simplify Bun setup for Windows ARM64 cjpais/Handy#965

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fix: use native Windows ARM64 binary for Bun >= 1.3.10#165

fix: use native Windows ARM64 binary for Bun >= 1.3.10#165
xhyrom merged 1 commit intooven-sh:mainfrom
oddrationale:fix/windows-arm64-native

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