feat(go): added support for embedding prompts into the binary

go/ai/prompt.go

@@ -19,10 +19,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io/fs"
 	"log/slog"
 	"maps"
-	"os"
-	"path/filepath"
+	"path"
 	"reflect"
 	"strings"
 
@@ -517,70 +517,54 @@ func convertToPartPointers(parts []dotprompt.Part) ([]*Part, error) {
 	return result, nil
 }
 
-// LoadPromptDir loads prompts and partials from the input directory for the given namespace.
-func LoadPromptDir(r api.Registry, dir string, namespace string) {
-	useDefaultDir := false
-	if dir == "" {
-		dir = "./prompts"
-		useDefaultDir = true
+// LoadPromptDirFromFS loads prompts and partials from a filesystem for the given namespace.
+// The fsys parameter should be an fs.FS implementation (e.g., embed.FS or os.DirFS).
+// The dir parameter specifies the directory within the filesystem where prompts are located.
+func LoadPromptDirFromFS(r api.Registry, fsys fs.FS, dir, namespace string) {
+	if fsys == nil {
+		panic(errors.New("no prompt filesystem provided"))
 	}
 
-	path, err := filepath.Abs(dir)
-	if err != nil {
-		if !useDefaultDir {
-			panic(fmt.Errorf("failed to resolve prompt directory %q: %w", dir, err))
-		}
-		slog.Debug("default prompt directory not found, skipping loading .prompt files", "dir", dir)
-		return
+	if _, err := fs.Stat(fsys, dir); err != nil {
+		panic(fmt.Errorf("failed to access prompt directory %q in filesystem: %w", dir, err))
 	}
 
-	if _, err := os.Stat(path); os.IsNotExist(err) {
-		if !useDefaultDir {
-			panic(fmt.Errorf("failed to resolve prompt directory %q: %w", dir, err))
-		}
-		slog.Debug("Default prompt directory not found, skipping loading .prompt files", "dir", dir)
-		return
-	}
-
-	loadPromptDir(r, path, namespace)
-}
-
-// loadPromptDir recursively loads prompts and partials from the directory.
-func loadPromptDir(r api.Registry, dir string, namespace string) {
-	entries, err := os.ReadDir(dir)
+	entries, err := fs.ReadDir(fsys, dir)
 	if err != nil {
 		panic(fmt.Errorf("failed to read prompt directory structure: %w", err))
 	}
 
 	for _, entry := range entries {
 		filename := entry.Name()
-		path := filepath.Join(dir, filename)
+		filePath := path.Join(dir, filename)
 		if entry.IsDir() {
-			loadPromptDir(r, path, namespace)
+			LoadPromptDirFromFS(r, fsys, filePath, namespace)
 		} else if strings.HasSuffix(filename, ".prompt") {
 			if strings.HasPrefix(filename, "_") {
 				partialName := strings.TrimSuffix(filename[1:], ".prompt")
-				source, err := os.ReadFile(path)
+				source, err := fs.ReadFile(fsys, filePath)
 				if err != nil {
 					slog.Error("Failed to read partial file", "error", err)
 					continue
 				}
 				r.RegisterPartial(partialName, string(source))
-				slog.Debug("Registered Dotprompt partial", "name", partialName, "file", path)
+				slog.Debug("Registered Dotprompt partial", "name", partialName, "file", filePath)
 			} else {
-				LoadPrompt(r, dir, filename, namespace)
+				LoadPromptFromFS(r, fsys, dir, filename, namespace)
 			}
 		}
 	}
 }
 
-// LoadPrompt loads a single prompt into the registry.
-func LoadPrompt(r api.Registry, dir, filename, namespace string) Prompt {
+// LoadPromptFromFS loads a single prompt from a filesystem into the registry.
+// The fsys parameter should be an fs.FS implementation (e.g., embed.FS or os.DirFS).
+// The dir parameter specifies the directory within the filesystem where the prompt is located.
+func LoadPromptFromFS(r api.Registry, fsys fs.FS, dir, filename, namespace string) Prompt {
 	name := strings.TrimSuffix(filename, ".prompt")
 	name, variant, _ := strings.Cut(name, ".")
 
-	sourceFile := filepath.Join(dir, filename)
-	source, err := os.ReadFile(sourceFile)
+	sourceFile := path.Join(dir, filename)
+	source, err := fs.ReadFile(fsys, sourceFile)
 	if err != nil {
 		slog.Error("Failed to read prompt file", "file", sourceFile, "error", err)
 		return nil
@@ -696,12 +680,10 @@ func LoadPrompt(r api.Registry, dir, filename, namespace string) Prompt {
 
 	promptOpts := []PromptOption{opts}
 
-	// Add system prompt if found
 	if systemText != "" {
 		promptOpts = append(promptOpts, WithSystem(systemText))
 	}
 
-	// If there are non-system messages, use WithMessages, otherwise use WithPrompt for template
 	if len(nonSystemMessages) > 0 {
 		promptOpts = append(promptOpts, WithMessages(nonSystemMessages...))
 	} else if systemText == "" {