fix(tools): list_files returns paths relative to queried directory — closes #24

[jpleva91]

Summary

• Bug: listFiles() called filepath.Rel(".", path), computing paths relative to the process cwd instead of the queried directory. Agents listing internal/agent received internal/agent/loop.go instead of loop.go, causing double-prefix errors on follow-up read_file calls.
• Fix: Use filepath.Rel(dir, path) anchored to the requested directory. Also skip the root "." entry so empty directories correctly return "(empty directory)".
• Tests: 5 new tests in TestListFiles_* covering relative paths, no-double-prefix regression, extension filter, empty directory, and hidden dir exclusion.

Test plan

• go build ./... passes
• go vet ./... passes
• go test ./... — all packages pass (including 5 new listFiles tests)
• Verify REPL list_files output shows leaf-relative paths in agent sessions

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes list_files path rendering so returned entries are relative to the directory being listed (not the process CWD), preventing “double-prefix” follow-up paths when agents call read_file on list results.

Changes:

• Compute listed paths via filepath.Rel(dir, path) (anchored to the queried directory) instead of filepath.Rel(".", path).
• Skip the root "." entry so truly empty directories return "(empty directory)".
• Add 5 new listFiles tests covering relative path behavior, regression for double-prefixing, extension filtering, empty directories, and hidden/node_modules exclusion.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
internal/tools/tools.go	Fixes listFiles() relative-path computation and skips the root entry.
internal/tools/tools_test.go	Adds test coverage for the corrected listFiles() output behavior and regressions.

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[Copilot]

filepath.Rel(dir, path) errors are currently ignored. If Rel fails (e.g., different volume on Windows, malformed input), rel becomes an empty string and the code may append "" or "/" to the output, producing incorrect paths. Handle the error explicitly (e.g., return it to fail the tool call, or skip the entry) before using rel.

Suggested change

	rel, _ := filepath.Rel(dir, path)
	rel, errRel := filepath.Rel(dir, path)
	if errRel != nil {
	return errRel
	}

[Copilot]

TestListFiles_PathsRelativeToDirectory only checks that output lines aren’t absolute and don’t start with the temp dir path. With the original bug, entries like "../../tmp/.../a.go" are still relative and would pass these assertions. To actually verify paths are relative to the queried directory, assert that returned paths don’t start with ".." (after filepath.Clean) / don’t contain parent traversals, or add a direct expectation like "sub/b.go" vs any prefixed path.

Suggested change

	// Paths must be relative to dir, not cwd
	for _, line := range strings.Split(r.Output, "\n") {
	if strings.HasPrefix(line, dir) {
	t.Fatalf("got absolute path %q — expected relative to listed dir", line)
	}
	// Paths must be relative to dir, not cwd, and must not contain parent traversals.
	for _, raw := range strings.Split(r.Output, "\n") {
	line := strings.TrimSpace(raw)
	if line == "" {
	continue
	}
	if strings.HasPrefix(line, dir) {
	t.Fatalf("got absolute path %q — expected relative to listed dir", line)
	}
	clean := filepath.Clean(line)
	if clean == ".." || strings.HasPrefix(clean, ".."+string(filepath.Separator)) {
	t.Fatalf("got path with parent traversal %q (clean: %q) — expected path relative to listed dir", line, clean)
	}

[jpleva91]

Reviewer: shellforge:reviewer (automated, 2026-04-02)

Code review: LGTM — would approve if self-review were permitted.

Fix correctness: filepath.Rel(dir, path) is the right anchor — "." resolves to process cwd, not the queried directory, so any absolute-path listing produced double-prefixed paths in the prior code. The rel == "." guard is also necessary: WalkDir visits the root directory itself first, and without this guard that visit emits a spurious . entry.

Tests: 5 targeted tests cover the core regression, no-double-prefix scenario, extension filter, empty dir, and hidden dir exclusion. Good coverage.

CI: All 5 checks passing (build, CodeQL, Analyze ×3).

One pre-existing note (not introduced here): filepath.Rel error is silently discarded. Safe on Linux (only errors cross-volume), but worth a comment if this function grows. Not a blocker.

Blast radius is minimal (2 files, 1 prod line changed). Ready to merge — needs a second reviewer from the team.