Add --resolve-extensions flag for custom test file patterns

[robobun]

Summary

This PR adds the --resolve-extensions CLI flag and resolveExtensions bunfig.toml property to allow users to customize which file name patterns are recognized as test files.

Motivation

Different projects and teams have different naming conventions for test files. While Bun's defaults (.test, _test, .spec, _spec) work well for most cases, some projects may prefer alternative patterns like .check, .verify, or other custom suffixes.

Features

CLI Flag

# Single custom extension
bun test --resolve-extensions .check

# Multiple custom extensions  
bun test --resolve-extensions .check --resolve-extensions .verify

bunfig.toml Configuration

[test]
# Single extension
resolveExtensions = ".check"

# Multiple extensions
resolveExtensions = [".check", ".verify"]

CLI Override

The CLI flag takes precedence over bunfig.toml configuration, allowing per-run customization.

Implementation Details

• Modified Scanner.zig to accept optional custom test name suffixes
• Added resolve_extensions field to TestOptions struct
• Implemented CLI argument parsing with support for multiple values
• Implemented bunfig.toml parsing with proper CLI override logic
• Updated error messages to dynamically show configured extensions
• All existing default behavior remains unchanged

Testing

Added comprehensive test suite covering:

• ✅ CLI flag with single extension
• ✅ CLI flag with multiple extensions
• ✅ bunfig.toml with string value
• ✅ bunfig.toml with array value
• ✅ CLI override of bunfig.toml
• ✅ Custom extensions with underscore prefix
• ✅ Error messages showing custom extensions
• ✅ Nested directory support
• ✅ Default behavior still works

All 9 tests pass successfully.

Documentation

• Added detailed markdown documentation in test/cli/test-resolve-extensions.md
• Includes usage examples and notes about precedence

---

🤖 Generated with Claude Code

Co-Authored-By: Claude [email protected]

[robobun]

^{Updated 6:17 PM PT - Nov 24th, 2025}

❌ Your commit 0dca0ee6 has 8 failures in Build #32365 (All Failures):

• test/js/bun/s3/s3.test.ts - 2 failing on 🐧 3.22 aarch64
• test/js/bun/s3/s3.test.ts - 1 failing on 🐧 3.22 x64
• test/js/bun/s3/s3.test.ts - 4 failing on 🐧 12 x64
• test/js/bun/s3/s3.test.ts - 2 failing on 🐧 25.04 x64
• test/js/bun/s3/s3.test.ts - 3 failing on 🐧 3.22 x64-baseline
• test/js/bun/s3/s3.test.ts - 1 failing on 🍎 14 x64
• test/v8/v8.test.ts - 1 failing on 🐧 12 x64-asan
• test/bake/dev/stress.test.ts - 1 failing on 🐧 3.22 x64-baseline
• test/bake/dev/stress.test.ts - 1 failing on 🐧 12 x64-baseline
• test/regression/issue/11297/11297.test.ts - 1 failing on 🪟 2019 x64-baseline
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🪟 2019 x64-baseline
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🪟 2019 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🍎 13 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🍎 14 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 12 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🍎 13 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 24.04 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 25.04 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 3.22 aarch64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 12 x64-asan
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 3.22 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 12 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 25.04 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 24.04 x64
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 3.22 x64-baseline
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 12 x64-baseline
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 24.04 x64-baseline
• test/js/third_party/grpc-js/test-resolver.test.ts - 3 failing on 🐧 25.04 x64-baseline
• test/integration/next-pages/test/dev-server.test.ts - 1 failing on 🍎 14 aarch64
• test/js/bun/ffi/cc.test.ts - 1 failing on 🍎 14 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🍎 14 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🪟 2019 x64-baseline
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🍎 13 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🪟 2019 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🍎 14 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 12 x64-asan
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 12 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 25.04 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 24.04 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 3.22 aarch64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 3.22 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 25.04 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 12 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 24.04 x64
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 3.22 x64-baseline
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 12 x64-baseline
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 24.04 x64-baseline
• test/cli/test/claudecode-flag.test.ts - 1 failing on 🐧 25.04 x64-baseline

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🧪   To try this PR locally:

bunx bun-pr 25049

That installs a local version of the PR into your bun-25049 executable, so you can run:

bun-25049 --bun