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review-bot/cmd/review-bot/validatedocmap_test.go
T
Rodin eb0ff3aa69
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nit(#150): clarify why resolved != symlinkPath in InRepoSymlinkAllowed test
Add a comment explaining that validateDocmapPath calls EvalSymlinks
internally, so the returned path is always the fully-resolved real path
and can never equal the symlink entry itself.

Addresses sonnet bot NIT (review 4810) against d6bab7a9.
2026-05-15 16:23:11 -07:00

697 lines
21 KiB
Go

package main
import (
"bytes"
"os"
"path/filepath"
"strings"
"testing"
)
// makeDocmapYAML writes a YAML string to a temp file and returns its path.
// The file is created in t.TempDir() — use makeDocmapInDir when the docmap
// must be located inside a specific repo-root directory.
func makeDocmapYAML(t *testing.T, content string) string {
t.Helper()
f, err := os.CreateTemp(t.TempDir(), "doc-map-*.yml")
if err != nil {
t.Fatalf("CreateTemp: %v", err)
}
defer f.Close()
if _, err := f.WriteString(content); err != nil {
t.Fatalf("WriteString: %v", err)
}
return f.Name()
}
// makeDocmapInDir writes a YAML string to a file inside dir and returns the
// file path. Use this instead of makeDocmapYAML when also passing --repo-root,
// because validateDocmapPath requires the docmap to be within the repo root.
func makeDocmapInDir(t *testing.T, dir, content string) string {
t.Helper()
if err := os.MkdirAll(filepath.Join(dir, ".review-bot"), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
path := filepath.Join(dir, ".review-bot", "doc-map.yml")
if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
return path
}
// makeDocFile creates a file (and any parent dirs) at the given path relative to dir.
func makeDocFile(t *testing.T, dir, rel string) {
t.Helper()
full := filepath.Join(dir, rel)
if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
if err := os.WriteFile(full, []byte("# doc\n"), 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
}
// captureOutput redirects outWriter/errWriter to buffers for the duration of f.
func captureOutput(f func()) (stdout, stderr string) {
var outBuf, errBuf bytes.Buffer
origOut, origErr := outWriter, errWriter
outWriter = &outBuf
errWriter = &errBuf
defer func() {
outWriter = origOut
errWriter = origErr
}()
f()
return outBuf.String(), errBuf.String()
}
func TestRunValidateDocmap_Clean(t *testing.T) {
dir := t.TempDir()
makeDocFile(t, dir, "docs/foo.md")
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
// A covered file with all docs existing → clean.
code, stdout, _ := stdinValidateDocmap(t,
"lib/foo/bar.ex\n",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 0 {
t.Errorf("expected exit 0 for clean, got %d", code)
}
if !strings.Contains(stdout, "OK") {
t.Errorf("expected 'OK' in stdout, got %q", stdout)
}
}
func TestRunValidateDocmap_MissingDocmapFlag(t *testing.T) {
var code int
_, stderr := captureOutput(func() {
code = runValidateDocmap([]string{})
})
if code != 2 {
t.Errorf("expected exit 2 for missing --docmap, got %d", code)
}
if !strings.Contains(stderr, "--docmap") {
t.Errorf("expected --docmap in stderr, got %q", stderr)
}
}
func TestRunValidateDocmap_BadYAML(t *testing.T) {
dir := t.TempDir()
docmap := makeDocmapInDir(t, dir, "mappings: [{{invalid")
var code int
_, stderr := captureOutput(func() {
code = runValidateDocmap([]string{"--docmap", docmap, "--repo-root", dir})
})
if code != 2 {
t.Errorf("expected exit 2 for bad YAML, got %d", code)
}
if !strings.Contains(stderr, "failed to parse") {
t.Errorf("expected parse error in stderr, got %q", stderr)
}
}
func TestRunValidateDocmap_StaleDocs(t *testing.T) {
dir := t.TempDir()
// docs/foo.md does NOT exist on disk.
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
var code int
_, stderr := captureOutput(func() {
code = runValidateDocmap([]string{
"--docmap", docmap,
"--repo-root", dir,
})
})
if code != 1 {
t.Errorf("expected exit 1 for stale docs, got %d", code)
}
if !strings.Contains(stderr, "docs/foo.md") {
t.Errorf("expected stale path in stderr, got %q", stderr)
}
if !strings.Contains(stderr, "stale docmap") {
t.Errorf("expected 'stale docmap' in stderr, got %q", stderr)
}
}
// stdinValidateDocmap runs runValidateDocmap with a synthetic stdin.
//
// Implementation note: we write stdinContent to a temp file and point
// os.Stdin at it. The defer f.Close() fires after stdinValidateDocmap
// returns, which is after runValidateDocmap has finished reading stdin
// synchronously — so the file is not closed while still in use.
// Tests must not call t.Parallel() while sharing the global os.Stdin.
func stdinValidateDocmap(t *testing.T, stdinContent string, args []string) (code int, stdout, stderr string) {
t.Helper()
// Write stdin content to a temp file and redirect os.Stdin.
f, err := os.CreateTemp(t.TempDir(), "stdin-*")
if err != nil {
t.Fatalf("CreateTemp for stdin: %v", err)
}
defer f.Close()
if _, err := f.WriteString(stdinContent); err != nil {
t.Fatalf("WriteString for stdin: %v", err)
}
if _, err := f.Seek(0, 0); err != nil {
t.Fatalf("Seek for stdin: %v", err)
}
origStdin := os.Stdin
os.Stdin = f
defer func() { os.Stdin = origStdin }()
stdout, stderr = captureOutput(func() {
code = runValidateDocmap(args)
})
return
}
func TestRunValidateDocmap_UncoveredFile(t *testing.T) {
dir := t.TempDir()
makeDocFile(t, dir, "docs/foo.md")
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
code, _, stderr := stdinValidateDocmap(t,
"lib/bar/uncovered.ex\n",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 1 {
t.Errorf("expected exit 1 for uncovered file, got %d", code)
}
if !strings.Contains(stderr, "lib/bar/uncovered.ex") {
t.Errorf("expected uncovered file in stderr, got %q", stderr)
}
if !strings.Contains(stderr, "no docmap coverage") {
t.Errorf("expected 'no docmap coverage' in stderr, got %q", stderr)
}
}
func TestRunValidateDocmap_BothFailures(t *testing.T) {
dir := t.TempDir()
// docs/foo.md intentionally missing
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
code, _, stderr := stdinValidateDocmap(t,
"lib/bar/uncovered.ex\n",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 1 {
t.Errorf("expected exit 1 for both failures, got %d", code)
}
if !strings.Contains(stderr, "no docmap coverage") {
t.Errorf("expected coverage error in stderr, got %q", stderr)
}
if !strings.Contains(stderr, "stale docmap") {
t.Errorf("expected stale-docs error in stderr, got %q", stderr)
}
}
func TestRunValidateDocmap_EmptyStdin(t *testing.T) {
dir := t.TempDir()
makeDocFile(t, dir, "docs/foo.md")
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
code, stdout, _ := stdinValidateDocmap(t,
"",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 0 {
t.Errorf("expected exit 0 for empty stdin, got %d", code)
}
if !strings.Contains(stdout, "OK") {
t.Errorf("expected 'OK' in stdout, got %q", stdout)
}
}
func TestRunValidateDocmap_BlankLinesSkipped(t *testing.T) {
dir := t.TempDir()
makeDocFile(t, dir, "docs/foo.md")
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/foo.md
`)
// stdin with only blank lines → effectively empty, should be clean
code, stdout, _ := stdinValidateDocmap(t,
"\n \n\n",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 0 {
t.Errorf("expected exit 0 for blank-only stdin, got %d", code)
}
if !strings.Contains(stdout, "OK") {
t.Errorf("expected 'OK' in stdout for blank-only stdin, got %q", stdout)
}
}
func TestRunValidateDocmap_DuplicateDocsDeduped(t *testing.T) {
dir := t.TempDir()
// docs/shared.md intentionally missing — but it appears in TWO mappings.
// Should appear only once in stale list.
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/foo/**"
docs:
- docs/shared.md
- paths:
- "lib/bar/**"
docs:
- docs/shared.md
`)
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 1 {
t.Errorf("expected exit 1 for stale doc, got %d", code)
}
count := strings.Count(stderr, "docs/shared.md")
if count != 1 {
t.Errorf("expected docs/shared.md to appear exactly once in stderr (deduplicated), got %d occurrences: %q", count, stderr)
}
}
// TestCheckStaleDocs_PathTraversal verifies that checkStaleDocs rejects
// traversal and absolute paths without touching the host filesystem.
func TestCheckStaleDocs_PathTraversal(t *testing.T) {
dir := t.TempDir()
// Baseline: a valid doc that exists.
makeDocFile(t, dir, "docs/valid.md")
tests := []struct {
name string
docPath string
wantStale bool
}{
{"dot-dot traversal", "../../etc/passwd", true},
{"dot-dot single", "../outside", true},
{"absolute path", "/etc/passwd", true},
{"valid present path", "docs/valid.md", false},
{"valid missing path", "docs/missing.md", true},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/**"
docs:
- `+tc.docPath+`
`)
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if tc.wantStale {
if code != 1 {
t.Errorf("path %q: expected exit 1 (stale/invalid), got %d; stderr: %q", tc.docPath, code, stderr)
}
} else {
if code != 0 {
t.Errorf("path %q: expected exit 0 (valid), got %d; stderr: %q", tc.docPath, code, stderr)
}
}
})
}
}
// TestCheckStaleDocs_SymlinkOutside verifies that a symlink under repoRoot
// pointing outside the repo is treated as stale (not followed).
func TestCheckStaleDocs_SymlinkOutside(t *testing.T) {
dir := t.TempDir()
// Create a symlink inside repoRoot pointing to a file outside the repo.
// We point at /etc/hostname (exists on Linux CI) but the test does not
// depend on that file existing — Lstat must reject the symlink itself.
linkPath := filepath.Join(dir, "docs", "secret.md")
if err := os.MkdirAll(filepath.Dir(linkPath), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
if err := os.Symlink("/etc/hostname", linkPath); err != nil {
t.Fatalf("Symlink: %v", err)
}
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/**"
docs:
- docs/secret.md
`)
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 1 {
t.Errorf("expected exit 1 for symlink doc, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stderr, "docs/secret.md") {
t.Errorf("expected stale path in stderr, got %q", stderr)
}
}
// TestCheckStaleDocs_SymlinkInsideRepo verifies that a symlink pointing to
// another file *within* the repo is also treated as stale. We refuse all
// symlinks regardless of target to keep the check simple and safe.
func TestCheckStaleDocs_SymlinkInsideRepo(t *testing.T) {
dir := t.TempDir()
// Real doc file.
makeDocFile(t, dir, "docs/real.md")
// Symlink inside repo pointing at the real file.
linkPath := filepath.Join(dir, "docs", "link.md")
if err := os.Symlink(filepath.Join(dir, "docs", "real.md"), linkPath); err != nil {
t.Fatalf("Symlink: %v", err)
}
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "lib/**"
docs:
- docs/link.md
`)
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 1 {
t.Errorf("expected exit 1 for symlink doc (even intra-repo), got %d; stderr: %q", code, stderr)
}
}
// TestRunValidateDocmap_SymlinkRepoRoot verifies that a --repo-root that is
// itself a symlink to a valid directory resolves correctly.
func TestRunValidateDocmap_SymlinkRepoRoot(t *testing.T) {
realDir := t.TempDir()
makeDocFile(t, realDir, "docs/foo.md")
// Create a symlink pointing at realDir.
symlinkDir := filepath.Join(t.TempDir(), "link-root")
if err := os.Symlink(realDir, symlinkDir); err != nil {
t.Fatalf("Symlink: %v", err)
}
// Place the docmap inside realDir so it passes the confinement check.
// (symlinkDir resolves to realDir, so files inside realDir are also inside
// the resolved repo-root.)
docmap := makeDocmapInDir(t, realDir, `
mappings:
- paths:
- "lib/**"
docs:
- docs/foo.md
`)
// Using the symlinked repo-root: the real doc exists → should be clean.
code, stdout, stderr := stdinValidateDocmap(t,
"lib/foo.go\n",
[]string{"--docmap", docmap, "--repo-root", symlinkDir},
)
if code != 0 {
t.Errorf("expected exit 0 for symlinked repo-root with existing doc, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stdout, "OK") {
t.Errorf("expected 'OK' in stdout, got %q", stdout)
}
}
// TestValidateDocmapPath_Symlink verifies that --docmap pointing at a symlink
// whose resolved target is outside --repo-root is rejected (prevents reading
// arbitrary host files via PR-controlled symlinks).
//
// Note: after the EvalSymlinks fix (issue #150), in-repo symlinks whose
// targets also reside within the repo root are now allowed — the confinement
// check is applied to the resolved path, not the symlink entry itself. The
// security invariant is: the resolved destination must be within the root.
func TestValidateDocmapPath_Symlink(t *testing.T) {
dir := t.TempDir()
outside := t.TempDir()
// Create a docmap file OUTSIDE the repo root to serve as the symlink
// target. EvalSymlinks will resolve to this path, which the Rel check
// must then reject.
if err := os.MkdirAll(filepath.Join(outside, ".review-bot"), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
outsideDocmap := filepath.Join(outside, ".review-bot", "doc-map.yml")
if err := os.WriteFile(outsideDocmap, []byte("mappings: []\n"), 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
// Create a symlink inside dir pointing to the file outside the repo.
if err := os.MkdirAll(filepath.Join(dir, ".review-bot"), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
symlinkPath := filepath.Join(dir, ".review-bot", "doc-map-link.yml")
if err := os.Symlink(outsideDocmap, symlinkPath); err != nil {
t.Fatalf("Symlink: %v", err)
}
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", symlinkPath, "--repo-root", dir},
)
if code != 2 {
t.Errorf("expected exit 2 for out-of-repo symlink docmap, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stderr, "invalid") && !strings.Contains(stderr, "repo-root") {
t.Errorf("expected confinement rejection in stderr, got %q", stderr)
}
}
// TestValidateDocmapPath_OutsideRepoRoot verifies that --docmap pointing
// outside --repo-root is rejected (prevents reading arbitrary host files).
func TestValidateDocmapPath_OutsideRepoRoot(t *testing.T) {
repoDir := t.TempDir()
// Create a docmap in a separate temp dir (outside the repo root).
outside := makeDocmapYAML(t, `
mappings:
- paths:
- "lib/**"
docs:
- docs/foo.md
`)
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", outside, "--repo-root", repoDir},
)
if code != 2 {
t.Errorf("expected exit 2 for docmap outside repo-root, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stderr, "invalid") && !strings.Contains(stderr, "repo-root") {
t.Errorf("expected confinement rejection in stderr, got %q", stderr)
}
}
// TestValidateDocmapPath_SizeLimit verifies that --docmap files exceeding
// maxDocmapBytes are rejected before reading (prevents memory exhaustion).
func TestValidateDocmapPath_SizeLimit(t *testing.T) {
dir := t.TempDir()
// Write a file larger than maxDocmapBytes.
bigPath := filepath.Join(dir, ".review-bot", "big-doc-map.yml")
if err := os.MkdirAll(filepath.Dir(bigPath), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
// Exceed the limit by one byte.
bigContent := make([]byte, maxDocmapBytes+1)
if err := os.WriteFile(bigPath, bigContent, 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", bigPath, "--repo-root", dir},
)
if code != 2 {
t.Errorf("expected exit 2 for oversized docmap, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stderr, "limit") && !strings.Contains(stderr, "size") && !strings.Contains(stderr, "invalid") {
t.Errorf("expected size limit error in stderr, got %q", stderr)
}
}
// TestValidateDocmapPath_DirSymlinkBypass verifies that a directory-symlink
// inside the repo pointing outside cannot be used to read arbitrary host files.
//
// Attack vector: a PR commits .review-bot/ as a directory symlink targeting a
// directory outside the repo. The textual path of the docmap file is inside
// the repo root, so the old Rel-only check passed — but the actual file is
// outside. This is closed by calling EvalSymlinks on the full path before the
// confinement check.
func TestValidateDocmapPath_DirSymlinkBypass(t *testing.T) {
repoDir := t.TempDir()
outsideDir := t.TempDir()
// Secret file outside the repo.
secretPath := filepath.Join(outsideDir, "secret.yml")
if err := os.WriteFile(secretPath, []byte("mappings: []\n"), 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
// Create .review-bot/ as a directory symlink pointing outside the repo.
reviewBotDir := filepath.Join(repoDir, ".review-bot")
if err := os.Symlink(outsideDir, reviewBotDir); err != nil {
t.Skipf("cannot create dir symlink (platform may not support it): %v", err)
}
// Textually inside repo — .review-bot/secret.yml — but resolves outside.
attackPath := filepath.Join(repoDir, ".review-bot", "secret.yml")
// Resolve repoDir to a symlink-free path, as runValidateDocmap does.
resolvedRoot, err := filepath.EvalSymlinks(repoDir)
if err != nil {
t.Fatalf("EvalSymlinks(repoDir): %v", err)
}
if _, err := validateDocmapPath(attackPath, resolvedRoot); err == nil {
t.Error("expected rejection of dir-symlink bypass, got nil error")
}
}
// TestValidateDocmapPath_NonRegularFile verifies that --docmap pointing at a
// non-regular file (e.g. a directory) is rejected with a clear error before
// ParseDocMapConfig is called.
func TestValidateDocmapPath_NonRegularFile(t *testing.T) {
dir := t.TempDir()
// Use the directory itself as the docmap path — directories pass Lstat but
// are not regular files.
reviewBotDir := filepath.Join(dir, ".review-bot")
if err := os.MkdirAll(reviewBotDir, 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
code, _, stderr := stdinValidateDocmap(t,
"",
[]string{"--docmap", reviewBotDir, "--repo-root", dir},
)
if code != 2 {
t.Errorf("expected exit 2 for directory docmap, got %d; stderr: %q", code, stderr)
}
if !strings.Contains(stderr, "regular file") && !strings.Contains(stderr, "invalid") {
t.Errorf("expected regular-file rejection in stderr, got %q", stderr)
}
}
// TestRunValidateDocmap_DotSlashPrefix verifies that paths emitted with a
// leading "./" (e.g. from `find` or `ls`) match doc-map globs correctly.
// Without TrimPrefix, "./cmd/foo.go" would not match the pattern "cmd/**".
func TestRunValidateDocmap_DotSlashPrefix(t *testing.T) {
dir := t.TempDir()
makeDocFile(t, dir, "docs/foo.md")
docmap := makeDocmapInDir(t, dir, `
mappings:
- paths:
- "cmd/**"
docs:
- docs/foo.md
`)
// File with a leading "./" should be treated as covered.
code, _, stderr := stdinValidateDocmap(t,
"./cmd/foo.go\n",
[]string{"--docmap", docmap, "--repo-root", dir},
)
if code != 0 {
t.Errorf("expected exit 0 for './' prefixed covered file, got %d; stderr: %q", code, stderr)
}
}
// TestValidateDocmapPath_InRepoSymlinkAllowed verifies that an in-repo
// file-level symlink whose resolved target is still within the repo root is
// accepted. This is the positive case for the issue #150 behavioral change:
// only symlinks that escape the root are rejected; intra-repo symlinks are
// allowed because EvalSymlinks resolves the target and the confinement check
// is applied to the resolved path, not the symlink entry itself.
func TestValidateDocmapPath_InRepoSymlinkAllowed(t *testing.T) {
dir := t.TempDir()
// Create the real docmap file inside the repo root.
if err := os.MkdirAll(filepath.Join(dir, ".review-bot"), 0o755); err != nil {
t.Fatalf("MkdirAll: %v", err)
}
realDocmap := filepath.Join(dir, ".review-bot", "doc-map-real.yml")
if err := os.WriteFile(realDocmap, []byte("mappings: []\n"), 0o644); err != nil {
t.Fatalf("WriteFile: %v", err)
}
// Create a symlink inside the repo root that points to the real file
// (also inside the root).
symlinkPath := filepath.Join(dir, ".review-bot", "doc-map-link.yml")
if err := os.Symlink(realDocmap, symlinkPath); err != nil {
t.Skipf("cannot create symlink (platform may not support it): %v", err)
}
// Resolve dir to a symlink-free root, as runValidateDocmap does.
resolvedRoot, err := filepath.EvalSymlinks(dir)
if err != nil {
t.Fatalf("EvalSymlinks(dir): %v", err)
}
// In-repo symlink whose target is within root: must be accepted.
resolved, err := validateDocmapPath(symlinkPath, resolvedRoot)
if err != nil {
t.Fatalf("expected in-repo symlink to be accepted, got error: %v", err)
}
// The returned resolved path must be the real file (not the symlink entry).
// validateDocmapPath calls filepath.EvalSymlinks internally, so the returned
// path is always the fully-resolved real path — it can never equal the
// symlink entry itself.
if resolved == symlinkPath {
t.Errorf("expected resolved path to differ from symlink path")
}
}