fix(dead-export-finder): resolve false negatives hiding all dead exports

[ryanbas21]

Summary

• Fix critical bug where CLI reported zero dead exports in all cases — @effect/cli's Options.repeated + Options.optional returns Some([]) not None, creating an empty package filter that rejected everything
• Inherit .gitignore patterns from workspace root during per-package scans, so dist/ build artifacts are properly excluded
• Add default ignore patterns for config files (*.config.{ts,mjs,cjs,js}) that export for tooling, not for code

Before: dead-export-finder → "No dead exports found" (always)
After: dead-export-finder → correctly reports 93 dead exports across 9 packages in this repo

Test plan

• 7 new unit tests covering empty packages regression, orphan files, cross-package consumption, gitignore inheritance, and config file exclusion (49 total, all passing)
• Verified on this repo: T from test.ts is caught, dist/ and config noise eliminated
• Full workspace scan produces clean, actionable results
• --packages filter still works when explicitly provided

🤖 Generated with Claude Code

[pullfrog]

No new issues found.

TL;DR — Fixes a critical false-negative bug where Options.repeated + Options.optional returns Some([]) not None, causing the CLI's package filter to silently reject all packages. Adds .gitignore inheritance from workspace root and default config-file exclusion patterns. Well-tested, clean implementation.

Key changes

• Fix empty-package filter bug — packagesOpt.value.length > 0 guard prevents Some([]) from creating a Set that filters out all packages
• Inherit .gitignore from workspace root — loadGitignorePatterns walks ancestor directories up to workspace root loading .gitignore files per-directory, with concurrent I/O via Effect.all
• Add default config-file ignore patterns — *.config.{ts,mjs,cjs,js} excluded by default since they export for tooling, not application code
• Add 7 new tests — regression test for the core bug, orphan vs star-re-export test, cross-package named import consumption + non-protection, gitignore inheritance, config-file exclusion, and a real-filesystem end-to-end test

_{Summary ｜ 6 files ｜ 1 commit ｜ base: main ← fix/dead-export-finder-false-negatives}

Package filter fix

Before: Some([]) creates new Set([]) → empty set rejects all packages → "No dead exports found"
After: packagesOpt.value.length > 0 ensures only non-empty Some values create a filter

1-2 sentence explanation needed per conventions. The root cause is that @effect/cli's Options.repeated + Options.optional returns Some([]) when the option is not provided — semantically the empty list and absence are distinct, but for the consumer they must be treated identically. The fix is minimal and correct.

cli.ts · export-graph.test.ts

Gitignore inheritance

Before: scanner loaded .gitignore only from the package root
After: scanner walks ancestor directories up to workspace root, collecting .gitignore from each level

The walker starts at dirname(root) and climbs via path.dirname until reaching workspaceRoot. Loop guards (current.length >= workspaceRoot.length and current !== pathSvc.dirname(current)) prevent runaway at the filesystem root. The per-directory .gitignore loads are dispatched concurrently.

file-scanner.ts · file-scanner.test.ts

Default config-file exclusions

Before: only node_modules was excluded by default
After: *.config.{ts,mjs,cjs,js} are also excluded

Config files like vite.config.ts, eslint.config.mjs, vitest.config.ts, etc. export for their respective tools — including them in dead-export analysis produces noise with no signal. Placing DEFAULT_IGNORE before gitignore patterns and custom globs means users can still opt specific config files back in if needed.

file-scanner.ts · file-scanner.test.ts

Tests

7 new tests across 3 test files, covering:

• Empty packages regression — confirms analyze([], …) produces zero dead exports
• Orphan file vs star re-export — star re-exports protect their source files; files outside star re-exports are still flagged
• Cross-package named import — importing { helperFn } from a package specifier marks it consumed
• Cross-package non-protection — importing one symbol doesn't protect unrelated symbols in the same package
• Gitignore inheritance — workspace-root .gitignore patterns are applied to nested packages
• Config-file exclusion — *.config.ts, *.config.mjs are excluded; index.ts is not
• E2E barrel coverage — real-filesystem pipeline verifies orphan files are flagged while barrel-protected and cross-package-consumed symbols are not

export-graph.test.ts · file-scanner.test.ts · integration.test.ts

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