Bugfixes and improved alignment with architecture blueprint

internal/prompt/go_renderer.go

@@ -13,6 +13,7 @@ var (
 	ErrMissingRequiredInput = errors.New("missing required input artifact")
 	ErrUnknownInput         = errors.New("referenced unknown input artifact")
 	ErrInvalidTemplate      = errors.New("invalid prompt template")
+	ErrRenderFailure        = errors.New("prompt render failure")
 	ErrInvalidMessageRole   = errors.New("invalid or empty message role")
 )
 
@@ -23,9 +24,14 @@ func NewGoRenderer() Renderer {
 }
 
 func (r *goRenderer) Render(ctx context.Context, profile *domain.PromptProfile, inputs map[string]*domain.Artifact, vars map[string]string) (*domain.RenderedPrompt, error) {
+	if profile == nil {
+		return nil, fmt.Errorf("%w: nil profile", ErrRenderFailure)
+	}
+
 	// 1. Verify required inputs
 	for _, req := range profile.ExpectedInputs {
-		if _, ok := inputs[req]; !ok {
+		art, ok := inputs[req]
+		if !ok || art == nil {
 			return nil, fmt.Errorf("%w: %s", ErrMissingRequiredInput, req)
 		}
 	}
@@ -44,19 +50,25 @@ func (r *goRenderer) Render(ctx context.Context, profile *domain.PromptProfile,
 	var renderedMessages []domain.RenderedMessage
 
 	for i, tmplMsg := range profile.Templates {
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		default:
+		}
+
 		if tmplMsg.Role == "" {
 			return nil, fmt.Errorf("%w: message %d", ErrInvalidMessageRole, i)
 		}
 
 		// Parse and execute template
-		tmpl, err := template.New(fmt.Sprintf("msg_%d", i)).Funcs(funcs).Parse(tmplMsg.Content)
+		tmpl, err := template.New(fmt.Sprintf("msg_%d", i)).Funcs(funcs).Option("missingkey=error").Parse(tmplMsg.Content)
 		if err != nil {
 			return nil, fmt.Errorf("%w: message %d: %v", ErrInvalidTemplate, i, err)
 		}
 
 		var buf bytes.Buffer
 		if err := tmpl.Execute(&buf, vars); err != nil {
-			return nil, fmt.Errorf("execution failed for message %d: %v", i, err)
+			return nil, fmt.Errorf("%w: message %d: %w", ErrRenderFailure, i, err)
 		}
 
 		renderedMessages = append(renderedMessages, domain.RenderedMessage{

internal/prompt/renderer_test.go

@@ -2,6 +2,7 @@ package prompt
 
 import (
 	"context"
+	"errors"
 	"testing"
 
 	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
@@ -47,7 +48,7 @@ func TestGoRenderer_Render(t *testing.T) {
 	t.Run("missing required input", func(t *testing.T) {
 		emptyInputs := map[string]*domain.Artifact{}
 		_, err := renderer.Render(ctx, profile, emptyInputs, vars)
-		if err == nil || (err != ErrMissingRequiredInput && err.Error() != "missing required input artifact: transcript") {
+		if !errors.Is(err, ErrMissingRequiredInput) {
 			t.Errorf("expected ErrMissingRequiredInput, got %v", err)
 		}
 	})
@@ -59,8 +60,11 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 		_, err := renderer.Render(ctx, profileUnknown, inputs, vars)
-		if err == nil {
-			t.Error("expected error for unknown input")
+		if !errors.Is(err, ErrRenderFailure) {
+			t.Errorf("expected ErrRenderFailure, got %v", err)
+		}
+		if !errors.Is(err, ErrUnknownInput) {
+			t.Errorf("expected ErrUnknownInput, got %v", err)
 		}
 	})
 
@@ -71,8 +75,8 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 		_, err := renderer.Render(ctx, profileInvalid, inputs, vars)
-		if err == nil {
-			t.Error("expected error for invalid template syntax")
+		if !errors.Is(err, ErrInvalidTemplate) {
+			t.Errorf("expected ErrInvalidTemplate, got %v", err)
 		}
 	})
 
@@ -83,8 +87,20 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 		_, err := renderer.Render(ctx, profileNoRole, inputs, vars)
-		if err == nil {
-			t.Error("expected error for empty message role")
+		if !errors.Is(err, ErrInvalidMessageRole) {
+			t.Errorf("expected ErrInvalidMessageRole, got %v", err)
+		}
+	})
+
+	t.Run("missing variable in template", func(t *testing.T) {
+		profileMissingVar := &domain.PromptProfile{
+			Templates: []domain.PromptMessageTemplate{
+				{Role: "system", Content: "You are {{.missing}}"},
+			},
+		}
+		_, err := renderer.Render(ctx, profileMissingVar, inputs, vars)
+		if !errors.Is(err, ErrRenderFailure) {
+			t.Errorf("expected ErrRenderFailure for missing variable, got %v", err)
 		}
 	})
 }