Expose layered configuration loading and inspection

lifecycle.go

@@ -87,6 +87,10 @@ func Load[T any](source Source, supplied ...Options[T]) (*Result[T], error) {
 		options[index] = toEngineOptions(supplied[index])
 	}
 	loaded, err := engine.Load(source.toEngine(), secretBinding(), options...)
+	return fromEngineLoaded(loaded, err)
+}
+
+func fromEngineLoaded[T any](loaded *engine.Loaded[T], err error) (*Result[T], error) {
 	if err != nil {
 		var loadError *engine.LoadError
 		if errors.As(err, &loadError) {
@@ -226,11 +230,7 @@ func toEngineOptions[T any](options Options[T]) engine.Options[T] {
 		Overlay:    options.Overlay,
 	}
 	if options.Filesystem != nil {
-		result.Filesystem = &engine.FilesystemContext{BaseDir: options.Filesystem.BaseDir, Root: options.Filesystem.Root}
-		if options.Filesystem.FS != nil {
-			filesystem := options.Filesystem.FS.value
-			result.Filesystem.FS = &filesystem
-		}
+		result.Filesystem = toEngineFilesystemContext(options.Filesystem)
 	}
 	if options.Overrides != nil {
 		result.Overrides = make([]engine.Override, len(options.Overrides))
@@ -243,6 +243,18 @@ func toEngineOptions[T any](options Options[T]) engine.Options[T] {
 	return result
 }
 
+func toEngineFilesystemContext(context *FilesystemContext) *engine.FilesystemContext {
+	if context == nil {
+		return nil
+	}
+	result := &engine.FilesystemContext{BaseDir: context.BaseDir, Root: context.Root}
+	if context.FS != nil {
+		filesystem := context.FS.value
+		result.FS = &filesystem
+	}
+	return result
+}
+
 func toEngineDefinition[T any](definition Definition[T]) engine.Definition[T] {
 	result := engine.Definition[T]{Defaults: definition.Defaults}
 	if definition.Resolve != nil {