go/.core/task/issue/258/spec.md

Issue 258: Smart Test Detection

Original Issue

https://forge.lthn.ai/core/cli/issues/258

Summary

Make core test smart — detect changed Go files and run only relevant tests.

Scope: Go-only. The existing core test command (internal/cmd/test/) targets Go projects (requires go.mod). Future language support (PHP, etc.) would be added as separate detection strategies, but this issue covers Go only.

Commands

core test                    # Run tests for changed files only
core test --all              # Run all tests (skip detection)
core test --filter UserTest  # Run specific test pattern
core test --coverage         # With coverage report
core test --base origin/dev  # Compare against specific base branch (CI)

Acceptance Criteria

• Detect changed .go files via git diff (local: HEAD, CI: origin/dev...HEAD)
• Handle renames, deletes, and new files via git diff --name-status
• Map source files to test files using N:M discovery (foo.go → foo_test.go, foo_integration_test.go, etc.)
• Warn when changed files have no corresponding tests
• Execute tests through existing runTest() infrastructure (not raw go test)
• Support --all flag to skip detection and run all tests
• Support --filter flag for test name pattern matching
• Support --coverage flag for coverage reports
• Support --base flag for CI/PR diff context

Technical Context

• Existing core test command: internal/cmd/test/cmd_main.go
• Existing test runner: internal/cmd/test/cmd_runner.go (runTest())
• Output parsing: internal/cmd/test/cmd_output.go
• Command registration: internal/cmd/test/cmd_commands.go via cli.RegisterCommands()
• Follow existing patterns in internal/cmd/test/