README.md

@@ -459,6 +459,41 @@ YAML is the recommended format for personas because it supports:
 
 JSON is also supported for backwards compatibility—just use `.json` extension.
 
+### Repository Personas (Auto-Discovery)
+
+Repositories can ship their own personas in `.review-bot/personas/`. When you specify `--persona <name>`, review-bot will:
+
+1. **Try to load from the target repo** — Checks `.review-bot/personas/<name>.yaml` (or `.yml`)
+2. **Fall back to built-in** — If not found in repo, uses the built-in persona
+
+This lets each repo define domain-specific personas without modifying CI config:
+
+```
+my-trading-repo/
+├── .review-bot/
+│   └── personas/
+│       ├── trading.yaml      # Custom trading persona
+│       └── regulatory.yaml   # Compliance-focused reviews
+├── lib/
+└── ...
+```
+
+```yaml
+# CI config (no persona-file needed)
+- uses: rodin/review-bot/.gitea/actions/review@v1
+  with:
+    reviewer-name: trading
+    persona: trading           # Will find .review-bot/personas/trading.yaml
+    ...
+```
+
+**Priority order:**
+1. Repo's `.review-bot/personas/<name>.yaml`
+2. Built-in persona with matching name
+3. Error if neither exists
+
+This allows repos to override built-in personas (e.g., a custom `security` persona that adds project-specific rules) while keeping the simple `persona: security` syntax in CI.
+
 
 ### Persona vs system-prompt-file
 

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 {
@@ -116,29 +115,9 @@ func main() {
 		os.Exit(1)
 	}
 
-	// Load persona if specified
+	// Persona loading is deferred until after giteaClient is initialized,
+	// so we can try loading from the target repo first.
 	var persona *review.Persona
-	if *personaName != "" {
-		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)
-	} else if *personaFile != "" {
-		resolvedPath, err := validateWorkspacePath(*personaFile, "persona-file")
-		if err != nil {
-			slog.Error("invalid persona-file path", "error", err)
-			os.Exit(1)
-		}
-		persona, err = review.LoadPersona(resolvedPath)
-		if err != nil {
-			slog.Error("failed to load persona file", "file", *personaFile, "error", err)
-			os.Exit(1)
-		}
-		slog.Info("loaded persona from file", "file", *personaFile, "persona", persona.Name)
-	}
 
 	// Validate reviewer-name: only safe characters allowed in sentinel
 	if err := validateReviewerName(*reviewerName); err != nil {
@@ -196,6 +175,45 @@ func main() {
 	ctx, cancel := context.WithTimeout(context.Background(), overallTimeout)
 	defer cancel()
 
+	// Load persona: try remote repo first, then fall back to built-in
+	if *personaName != "" {
+		// Try loading from target repo's .review-bot/personas/ directory
+		fetcher := &giteaFetcher{client: giteaClient}
+		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 {
+			persona = p
+			slog.Info("loaded persona from target repo", "persona", persona.Name, "display", persona.DisplayName)
+		} else {
+			// Fall back to built-in persona
+			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)
+		}
+	} else if *personaFile != "" {
+		resolvedPath, err := validateWorkspacePath(*personaFile, "persona-file")
+		if err != nil {
+			slog.Error("invalid persona-file path", "error", err)
+			os.Exit(1)
+		}
+		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)
+	}
+
 	slog.Info("reviewing pull request", "pr", prNumber, "repo", fmt.Sprintf("%s/%s", owner, repoName))
 
 	// Step 1: Fetch PR metadata
@@ -783,3 +801,29 @@ func shouldSkipStaleReview(evaluatedSHA, currentSHA string) bool {
 	}
 	return evaluatedSHA != currentSHA
 }
+
+// giteaFetcher adapts gitea.Client to review.PersonaFetcher interface.
+type giteaFetcher struct {
+	client *gitea.Client
+}
+
+func (f *giteaFetcher) ListContents(ctx context.Context, owner, repo, path string) ([]review.ContentEntry, error) {
+	entries, err := f.client.ListContents(ctx, owner, repo, path)
+	if err != nil {
+		return nil, err
+	}
+	// Convert gitea.ContentEntry to review.ContentEntry
+	result := make([]review.ContentEntry, len(entries))
+	for i, e := range entries {
+		result[i] = review.ContentEntry{
+			Name: e.Name,
+			Path: e.Path,
+			Type: e.Type,
+		}
+	}
+	return result, nil
+}
+
+func (f *giteaFetcher) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+	return f.client.GetFileContent(ctx, owner, repo, filepath)
+}

review/remote_persona.go

@@ -0,0 +1,164 @@
+package review
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"sort"
+	"strings"
+)
+
+// PersonaFetcher abstracts fetching files from a remote repository.
+// This allows persona loading to work with any Git host API.
+type PersonaFetcher interface {
+	// ListContents returns file/directory entries at a path.
+	// Returns an error if the path doesn't exist or isn't accessible.
+	ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error)
+
+	// GetFileContent returns the raw content of a file from the default branch.
+	GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error)
+}
+
+// ContentEntry represents a file or directory entry.
+type ContentEntry struct {
+	Name string // filename or directory name
+	Path string // full path from repo root
+	Type string // "file" or "dir"
+}
+
+// DefaultPersonasPath is the conventional location for repo-specific personas.
+const DefaultPersonasPath = ".review-bot/personas"
+
+// LoadRemotePersonas fetches personas from a remote repository's .review-bot/personas/ directory.
+// Returns a map of persona name to Persona. If the directory doesn't exist or is empty,
+// returns an empty map with no error (graceful fallback to built-in personas).
+//
+// Files larger than MaxPersonaFileSize are logged and skipped.
+// Invalid YAML files are logged and skipped (partial success model).
+// Only .yaml and .yml files are processed; other files are ignored.
+func LoadRemotePersonas(ctx context.Context, fetcher PersonaFetcher, owner, repo string) (map[string]*Persona, error) {
+	return LoadRemotePersonasFromPath(ctx, fetcher, owner, repo, DefaultPersonasPath)
+}
+
+// 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 {
+		// 404 is expected when repo doesn't have personas — return empty, not error
+		if isNotFoundError(err) {
+			slog.Debug("no remote personas directory found", "repo", fmt.Sprintf("%s/%s", owner, repo), "path", path)
+			return map[string]*Persona{}, nil
+		}
+		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()
+		}
+
+		// Skip directories and non-YAML files
+		if entry.Type != "file" {
+			continue
+		}
+		if !isYAMLFile(entry.Name) {
+			continue
+		}
+
+		content, err := fetcher.GetFileContent(ctx, owner, repo, entry.Path)
+		if err != nil {
+			slog.Warn("could not fetch remote persona file", "file", entry.Path, "error", err)
+			continue
+		}
+
+		// Check size before parsing (defense in depth)
+		if len(content) > MaxPersonaFileSize {
+			slog.Warn("remote persona file exceeds size limit", "file", entry.Path, "size", len(content), "limit", MaxPersonaFileSize)
+			continue
+		}
+
+		persona, err := parsePersona([]byte(content), entry.Path)
+		if err != nil {
+			slog.Warn("could not parse remote persona file", "file", entry.Path, "error", err)
+			continue
+		}
+
+		result[persona.Name] = persona
+		processed++
+		slog.Debug("loaded remote persona", "name", persona.Name, "file", entry.Path)
+	}
+
+	return result, nil
+}
+
+// MergePersonas combines remote and built-in personas.
+// Remote personas take precedence on name collision.
+// Returns the merged map and a list of persona names in sorted order.
+func MergePersonas(remote, builtin map[string]*Persona) (map[string]*Persona, []string) {
+	merged := make(map[string]*Persona)
+
+	// Add built-in first
+	for name, p := range builtin {
+		merged[name] = p
+	}
+
+	// Remote overrides built-in on collision
+	for name, p := range remote {
+		if _, exists := merged[name]; exists {
+			slog.Debug("remote persona overrides built-in", "name", name)
+		}
+		merged[name] = p
+	}
+
+	// Collect sorted names
+	names := make([]string, 0, len(merged))
+	for name := range merged {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	return merged, names
+}
+
+// LoadAllBuiltinPersonas loads all built-in personas into a map.
+func LoadAllBuiltinPersonas() map[string]*Persona {
+	result := make(map[string]*Persona)
+	for _, name := range ListBuiltinPersonas() {
+		p, err := LoadBuiltinPersona(name)
+		if err != nil {
+			slog.Warn("could not load built-in persona", "name", name, "error", err)
+			continue
+		}
+		result[name] = p
+	}
+	return result
+}
+
+// isYAMLFile returns true if the filename has a YAML extension.
+func isYAMLFile(name string) bool {
+	lower := strings.ToLower(name)
+	return strings.HasSuffix(lower, ".yaml") || strings.HasSuffix(lower, ".yml")
+}
+
+// isNotFoundError checks if an error indicates a 404 response.
+// This is a simple string check to avoid importing the gitea package
+// (which would create a circular dependency).
+func isNotFoundError(err error) bool {
+	if err == nil {
+		return false
+	}
+	errStr := err.Error()
+	return strings.Contains(errStr, "HTTP 404")
+}

review/remote_persona_test.go

@@ -0,0 +1,394 @@
+package review
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+// mockFetcher implements PersonaFetcher for testing.
+type mockFetcher struct {
+	contents     map[string][]ContentEntry // path -> entries
+	files        map[string]string         // path -> content
+	listErr      error                     // error to return from ListContents
+	getFileErr   map[string]error          // path -> error for GetFileContent
+	listNotFound bool                      // return 404-style error
+}
+
+func newMockFetcher() *mockFetcher {
+	return &mockFetcher{
+		contents:   make(map[string][]ContentEntry),
+		files:      make(map[string]string),
+		getFileErr: make(map[string]error),
+	}
+}
+
+func (m *mockFetcher) ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error) {
+	if m.listNotFound {
+		return nil, errors.New("HTTP 404: not found")
+	}
+	if m.listErr != nil {
+		return nil, m.listErr
+	}
+	entries, ok := m.contents[path]
+	if !ok {
+		return nil, errors.New("HTTP 404: not found")
+	}
+	return entries, nil
+}
+
+func (m *mockFetcher) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+	if err, ok := m.getFileErr[filepath]; ok {
+		return "", err
+	}
+	content, ok := m.files[filepath]
+	if !ok {
+		return "", errors.New("HTTP 404: file not found")
+	}
+	return content, nil
+}
+
+func TestLoadRemotePersonas_NoDirectory(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.listNotFound = true
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("expected no error for missing directory, got: %v", err)
+	}
+	if len(result) != 0 {
+		t.Errorf("expected empty map, got %d personas", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_EmptyDirectory(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{}
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 0 {
+		t.Errorf("expected empty map, got %d personas", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_SinglePersona(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "trading.yaml", Path: ".review-bot/personas/trading.yaml", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/trading.yaml"] = `
+name: trading
+display_name: Trading Expert
+identity: You are a trading systems expert.
+focus:
+  - order execution
+  - market data
+`
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 1 {
+		t.Fatalf("expected 1 persona, got %d", len(result))
+	}
+	if result["trading"] == nil {
+		t.Fatal("expected 'trading' persona")
+	}
+	if result["trading"].DisplayName != "Trading Expert" {
+		t.Errorf("expected display name 'Trading Expert', got %q", result["trading"].DisplayName)
+	}
+}
+
+func TestLoadRemotePersonas_MultiplePersonas(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "one.yaml", Path: ".review-bot/personas/one.yaml", Type: "file"},
+		{Name: "two.yml", Path: ".review-bot/personas/two.yml", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/one.yaml"] = `
+name: one
+identity: First persona.
+`
+	fetcher.files[".review-bot/personas/two.yml"] = `
+name: two
+identity: Second persona.
+`
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 2 {
+		t.Fatalf("expected 2 personas, got %d", len(result))
+	}
+	if result["one"] == nil || result["two"] == nil {
+		t.Error("expected both personas to be loaded")
+	}
+}
+
+func TestLoadRemotePersonas_SkipsNonYAML(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "valid.yaml", Path: ".review-bot/personas/valid.yaml", Type: "file"},
+		{Name: "readme.md", Path: ".review-bot/personas/readme.md", Type: "file"},
+		{Name: "config.json", Path: ".review-bot/personas/config.json", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/valid.yaml"] = `
+name: valid
+identity: Valid persona.
+`
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 1 {
+		t.Fatalf("expected 1 persona (skipping non-YAML), got %d", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_SkipsDirectories(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "valid.yaml", Path: ".review-bot/personas/valid.yaml", Type: "file"},
+		{Name: "subdir", Path: ".review-bot/personas/subdir", Type: "dir"},
+	}
+	fetcher.files[".review-bot/personas/valid.yaml"] = `
+name: valid
+identity: Valid persona.
+`
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 1 {
+		t.Fatalf("expected 1 persona (skipping dir), got %d", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_SkipsInvalidYAML(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "valid.yaml", Path: ".review-bot/personas/valid.yaml", Type: "file"},
+		{Name: "invalid.yaml", Path: ".review-bot/personas/invalid.yaml", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/valid.yaml"] = `
+name: valid
+identity: Valid persona.
+`
+	fetcher.files[".review-bot/personas/invalid.yaml"] = `
+this is not valid yaml: [unclosed bracket
+`
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 1 {
+		t.Fatalf("expected 1 persona (skipping invalid), got %d", len(result))
+	}
+	if result["valid"] == nil {
+		t.Error("expected valid persona to be loaded")
+	}
+}
+
+func TestLoadRemotePersonas_SkipsOversizedFiles(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "huge.yaml", Path: ".review-bot/personas/huge.yaml", Type: "file"},
+	}
+	// Create content larger than MaxPersonaFileSize (64KB)
+	fetcher.files[".review-bot/personas/huge.yaml"] = `
+name: huge
+identity: ` + string(make([]byte, MaxPersonaFileSize+1000))
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 0 {
+		t.Errorf("expected 0 personas (oversized file skipped), got %d", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_SkipsFetchErrors(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "valid.yaml", Path: ".review-bot/personas/valid.yaml", Type: "file"},
+		{Name: "error.yaml", Path: ".review-bot/personas/error.yaml", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/valid.yaml"] = `
+name: valid
+identity: Valid persona.
+`
+	fetcher.getFileErr[".review-bot/personas/error.yaml"] = errors.New("network error")
+
+	result, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result) != 1 {
+		t.Fatalf("expected 1 persona (skipping error), got %d", len(result))
+	}
+}
+
+func TestLoadRemotePersonas_ListContentsError(t *testing.T) {
+	fetcher := newMockFetcher()
+	fetcher.listErr = errors.New("server error")
+
+	_, err := LoadRemotePersonas(context.Background(), fetcher, "owner", "repo")
+	if err == nil {
+		t.Fatal("expected error for list contents failure")
+	}
+}
+
+func TestLoadRemotePersonas_ContextCancellation(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // Cancel immediately
+
+	fetcher := newMockFetcher()
+	fetcher.contents[DefaultPersonasPath] = []ContentEntry{
+		{Name: "one.yaml", Path: ".review-bot/personas/one.yaml", Type: "file"},
+	}
+	fetcher.files[".review-bot/personas/one.yaml"] = `
+name: one
+identity: One.
+`
+
+	_, err := LoadRemotePersonas(ctx, fetcher, "owner", "repo")
+	if err == nil {
+		t.Fatal("expected context cancellation error")
+	}
+}
+
+func TestMergePersonas_NoOverlap(t *testing.T) {
+	remote := map[string]*Persona{
+		"trading": {Name: "trading", Identity: "Trading expert."},
+	}
+	builtin := map[string]*Persona{
+		"security": {Name: "security", Identity: "Security expert."},
+	}
+
+	merged, names := MergePersonas(remote, builtin)
+
+	if len(merged) != 2 {
+		t.Fatalf("expected 2 personas, got %d", len(merged))
+	}
+	if len(names) != 2 {
+		t.Fatalf("expected 2 names, got %d", len(names))
+	}
+	// Names should be sorted
+	if names[0] != "security" || names[1] != "trading" {
+		t.Errorf("expected sorted names [security, trading], got %v", names)
+	}
+}
+
+func TestMergePersonas_RemoteOverridesBuiltin(t *testing.T) {
+	remote := map[string]*Persona{
+		"security": {Name: "security", Identity: "Custom security expert."},
+	}
+	builtin := map[string]*Persona{
+		"security": {Name: "security", Identity: "Default security expert."},
+	}
+
+	merged, _ := MergePersonas(remote, builtin)
+
+	if merged["security"].Identity != "Custom security expert." {
+		t.Errorf("expected remote to override builtin, got identity: %q", merged["security"].Identity)
+	}
+}
+
+func TestMergePersonas_EmptyRemote(t *testing.T) {
+	remote := map[string]*Persona{}
+	builtin := map[string]*Persona{
+		"security": {Name: "security", Identity: "Security."},
+	}
+
+	merged, names := MergePersonas(remote, builtin)
+
+	if len(merged) != 1 {
+		t.Fatalf("expected 1 persona, got %d", len(merged))
+	}
+	if names[0] != "security" {
+		t.Errorf("expected 'security', got %q", names[0])
+	}
+}
+
+func TestMergePersonas_EmptyBuiltin(t *testing.T) {
+	remote := map[string]*Persona{
+		"trading": {Name: "trading", Identity: "Trading."},
+	}
+	builtin := map[string]*Persona{}
+
+	merged, names := MergePersonas(remote, builtin)
+
+	if len(merged) != 1 {
+		t.Fatalf("expected 1 persona, got %d", len(merged))
+	}
+	if names[0] != "trading" {
+		t.Errorf("expected 'trading', got %q", names[0])
+	}
+}
+
+func TestLoadAllBuiltinPersonas(t *testing.T) {
+	personas := LoadAllBuiltinPersonas()
+
+	// Should load at least the known built-in personas
+	expected := []string{"architect", "docs", "security"}
+	for _, name := range expected {
+		if personas[name] == nil {
+			t.Errorf("expected built-in persona %q to be loaded", name)
+		}
+	}
+}
+
+func TestIsYAMLFile(t *testing.T) {
+	tests := []struct {
+		name     string
+		expected bool
+	}{
+		{"test.yaml", true},
+		{"test.yml", true},
+		{"test.YAML", true},
+		{"test.YML", true},
+		{"test.json", false},
+		{"test.md", false},
+		{"yaml", false},
+		{"", false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := isYAMLFile(tc.name); got != tc.expected {
+				t.Errorf("isYAMLFile(%q) = %v, want %v", tc.name, got, tc.expected)
+			}
+		})
+	}
+}
+
+func TestIsNotFoundError(t *testing.T) {
+	tests := []struct {
+		name     string
+		err      error
+		expected bool
+	}{
+		{"nil error", nil, false},
+		{"HTTP 404", errors.New("HTTP 404: 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},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := isNotFoundError(tc.err); got != tc.expected {
+				t.Errorf("isNotFoundError(%v) = %v, want %v", tc.err, got, tc.expected)
+			}
+		})
+	}
+}