Centralize message role invariants

internal/promptdef/filesystem_repository.go

@@ -254,20 +254,27 @@ func normalizePromptDefinitionWithContent(raw *promptDefinitionFile, readContent
 
 	templates := make([]domain.PromptMessageTemplate, 0, len(raw.Messages))
 	for i, msg := range raw.Messages {
-		role := strings.TrimSpace(msg.Role)
-		if role == "" {
-			return nil, fmt.Errorf("message %d role is required", i)
+		role, err := domain.NormalizeMessageRole(msg.Role)
+		if err != nil {
+			return nil, fmt.Errorf("message %d role: %w", i, err)
 		}
 
 		hasContent := strings.TrimSpace(msg.Content) != ""
 		hasContentFile := strings.TrimSpace(msg.ContentFile) != ""
 		if hasContent == hasContentFile {
-			return nil, fmt.Errorf("message %d (%s) must set exactly one of content or content_file", i, role)
+			return nil, fmt.Errorf("message %d must set exactly one of content or content_file", i)
 		}
 
-		cacheControl, err := normalizeCacheControl(msg.CacheControl)
+		var rawCacheControl *domain.CacheControl
+		if msg.CacheControl != nil {
+			rawCacheControl = &domain.CacheControl{
+				Type: domain.CacheControlType(msg.CacheControl.Type),
+				TTL:  msg.CacheControl.TTL,
+			}
+		}
+		cacheControl, err := domain.NormalizeCacheControl(rawCacheControl)
 		if err != nil {
-			return nil, fmt.Errorf("message %d (%s) cache_control: %w", i, role, err)
+			return nil, fmt.Errorf("message %d cache_control: %w", i, err)
 		}
 
 		templateContent := msg.Content
@@ -275,7 +282,7 @@ func normalizePromptDefinitionWithContent(raw *promptDefinitionFile, readContent
 		if hasContentFile {
 			body, resolvedPath, err := readContentFile(msg.ContentFile)
 			if err != nil {
-				return nil, fmt.Errorf("prompt %q message %d (%s): failed to read content_file %q: %w", id, i, role, msg.ContentFile, err)
+				return nil, fmt.Errorf("prompt %q message %d: failed to read content_file %q: %w", id, i, msg.ContentFile, err)
 			}
 			templateContent = body
 			resolvedContentFile = resolvedPath
@@ -319,27 +326,3 @@ func normalizePromptDefinitionWithContent(raw *promptDefinitionFile, readContent
 		Validation:     outputContract,
 	}, nil
 }
-
-func normalizeCacheControl(raw *cacheControlFile) (*domain.CacheControl, error) {
-	if raw == nil {
-		return nil, nil
-	}
-
-	cacheType := strings.TrimSpace(raw.Type)
-	if cacheType == "" {
-		return nil, errors.New("type is required")
-	}
-	if domain.CacheControlType(cacheType) != domain.CacheControlEphemeral {
-		return nil, fmt.Errorf("unsupported type %q", cacheType)
-	}
-
-	ttl := strings.TrimSpace(raw.TTL)
-	if ttl != "" && ttl != "1h" {
-		return nil, fmt.Errorf("unsupported ttl %q", ttl)
-	}
-
-	return &domain.CacheControl{
-		Type: domain.CacheControlType(cacheType),
-		TTL:  ttl,
-	}, nil
-}

internal/promptdef/repository_test.go

@@ -1087,6 +1087,48 @@ output:
 	}
 }
 
+func TestPromptDefinitionMessageRoleNormalization(t *testing.T) {
+	const invalidRole = "consumer-private-role"
+	repo := NewFSRepository(fstest.MapFS{
+		"canonical.yaml": {Data: []byte(`
+id: canonical
+version: "1"
+messages:
+  - role: " \u2003SyStEm\u2003 "
+    content: test
+output:
+  format: text
+  validation_mode: none
+`)},
+		"invalid.yaml": {Data: []byte(`
+id: invalid-role
+version: "1"
+messages:
+  - role: consumer-private-role
+    content: test
+output:
+  format: text
+  validation_mode: none
+`)},
+	}, ".")
+
+	definition, err := repo.GetPromptDefinition(context.Background(), "canonical", "")
+	if err != nil {
+		t.Fatalf("GetPromptDefinition() error = %v", err)
+	}
+	if got := definition.Templates[0].Role; got != domain.RoleSystem {
+		t.Fatalf("normalized role = %q, want %q", got, domain.RoleSystem)
+	}
+
+	_, err = repo.GetPromptDefinition(context.Background(), "invalid-role", "")
+	if !errors.Is(err, ErrInvalidPromptDefinition) {
+		t.Fatalf("expected ErrInvalidPromptDefinition, got %v", err)
+	}
+	if strings.Contains(err.Error(), invalidRole) {
+		t.Fatalf("invalid prompt error exposed the supplied role: %v", err)
+	}
+}
+
 func assertCacheControl(t *testing.T, got *domain.CacheControl, wantType domain.CacheControlType, wantTTL string) {
 	t.Helper()
 	if got == nil {