fix: address PR #62 review findings

- Remove duplicate flag.Parse() call
- Fix nil map panic in LoadRemotePersonas error path by assigning
  empty map when LoadRemotePersonas returns an error
- Tighten isNotFoundError to only check HTTP 404 (remove broad
  'not found' substring check to avoid false positives)
- Clean up personaErr variable scope using narrower-scoped err variables
- Add proper doc comment to LoadRemotePersonasFromPath (Go convention)
- Add file count cap (50 files) in LoadRemotePersonasFromPath to
  prevent resource exhaustion from repos with thousands of small files
- Update test expectation for tightened isNotFoundError

cmd/review-bot/main.go

@@ -79,7 +79,6 @@ func main() {
 	aicoreAPIURL := flag.String("aicore-api-url", envOrDefault("AICORE_API_URL", ""), "SAP AI Core API URL (for provider=aicore)")
 	aicoreResourceGroup := flag.String("aicore-resource-group", envOrDefault("AICORE_RESOURCE_GROUP", "default"), "SAP AI Core resource group (for provider=aicore)")
 
-	flag.Parse()
 	flag.Parse()
 
 	if *versionFlag {
@@ -119,7 +118,6 @@ func main() {
 	// Persona loading is deferred until after giteaClient is initialized,
 	// so we can try loading from the target repo first.
 	var persona *review.Persona
-	var personaErr error
 
 	// Validate reviewer-name: only safe characters allowed in sentinel
 	if err := validateReviewerName(*reviewerName); err != nil {
@@ -184,6 +182,8 @@ func main() {
 		remotePersonas, err := review.LoadRemotePersonas(ctx, fetcher, owner, repoName)
 		if err != nil {
 			slog.Warn("could not load remote personas", "repo", fmt.Sprintf("%s/%s", owner, repoName), "error", err)
+			// Assign empty map so the lookup below doesn't panic
+			remotePersonas = map[string]*review.Persona{}
 		}
 
 		if p, ok := remotePersonas[*personaName]; ok {
@@ -191,9 +191,10 @@ func main() {
 			slog.Info("loaded persona from target repo", "persona", persona.Name, "display", persona.DisplayName)
 		} else {
 			// Fall back to built-in persona
-			persona, personaErr = review.LoadBuiltinPersona(*personaName)
-			if personaErr != nil {
-				slog.Error("failed to load persona", "persona", *personaName, "error", personaErr)
+			var err error
+			persona, err = review.LoadBuiltinPersona(*personaName)
+			if err != nil {
+				slog.Error("failed to load persona", "persona", *personaName, "error", err)
 				os.Exit(1)
 			}
 			slog.Info("loaded built-in persona", "persona", persona.Name, "display", persona.DisplayName)
@@ -204,9 +205,10 @@ func main() {
 			slog.Error("invalid persona-file path", "error", err)
 			os.Exit(1)
 		}
-		persona, personaErr = review.LoadPersona(resolvedPath)
-		if personaErr != nil {
-			slog.Error("failed to load persona file", "file", *personaFile, "error", personaErr)
+		var err2 error
+		persona, err2 = review.LoadPersona(resolvedPath)
+		if err2 != nil {
+			slog.Error("failed to load persona file", "file", *personaFile, "error", err2)
 			os.Exit(1)
 		}
 		slog.Info("loaded persona from file", "file", *personaFile, "persona", persona.Name)

review/remote_persona.go

@@ -40,7 +40,9 @@ func LoadRemotePersonas(ctx context.Context, fetcher PersonaFetcher, owner, repo
 	return LoadRemotePersonasFromPath(ctx, fetcher, owner, repo, DefaultPersonasPath)
 }
 
-// LoadRemotePersonasFromPath is like LoadRemotePersonas but allows specifying a custom path.
+// LoadRemotePersonasFromPath loads personas from a custom path in a remote repository.
+// It behaves the same as LoadRemotePersonas but allows specifying a path other than
+// the default .review-bot/personas directory.
 func LoadRemotePersonasFromPath(ctx context.Context, fetcher PersonaFetcher, owner, repo, path string) (map[string]*Persona, error) {
 	entries, err := fetcher.ListContents(ctx, owner, repo, path)
 	if err != nil {
@@ -52,8 +54,17 @@ func LoadRemotePersonasFromPath(ctx context.Context, fetcher PersonaFetcher, own
 		return nil, fmt.Errorf("list remote personas: %w", err)
 	}
 
+	// Cap the number of files to process to prevent resource exhaustion
+	// from repos with thousands of small files.
+	const maxPersonaFiles = 50
+
 	result := make(map[string]*Persona)
+	processed := 0
 	for _, entry := range entries {
+		if processed >= maxPersonaFiles {
+			slog.Warn("persona file limit reached", "limit", maxPersonaFiles, "repo", fmt.Sprintf("%s/%s", owner, repo))
+			break
+		}
 		if ctx.Err() != nil {
 			return nil, ctx.Err()
 		}
@@ -85,6 +96,7 @@ func LoadRemotePersonasFromPath(ctx context.Context, fetcher PersonaFetcher, own
 		}
 
 		result[persona.Name] = persona
+		processed++
 		slog.Debug("loaded remote persona", "name", persona.Name, "file", entry.Path)
 	}
 
@@ -148,5 +160,5 @@ func isNotFoundError(err error) bool {
 		return false
 	}
 	errStr := err.Error()
-	return strings.Contains(errStr, "HTTP 404") || strings.Contains(errStr, "not found")
+	return strings.Contains(errStr, "HTTP 404")
 }

review/remote_persona_test.go

@@ -379,7 +379,7 @@ func TestIsNotFoundError(t *testing.T) {
 	}{
 		{"nil error", nil, false},
 		{"HTTP 404", errors.New("HTTP 404: not found"), true},
-		{"not found text", errors.New("path not found"), true},
+		{"not found text", errors.New("path not found"), false},
 		{"server error", errors.New("server error"), false},
 		{"HTTP 500", errors.New("HTTP 500: internal error"), false},
 	}