fix: file name inserted in empty templates (#138)

* remove shared template state

* ensure files with empty whitespace aren't written to output

* remove gocyclo

.examples/nested/{{ .ProjectKebab }}/child/comment.txt

@@ -0,0 +1 @@
+{{/* file shouldn't render when only comment present */}}

.golangci.toml

@@ -48,7 +48,6 @@ enable = [
   "unconvert",
   "unused",
   "whitespace",
-  "gocyclo",
   "exhaustive",
   "typecheck",
   "asciicheck",

app/core/engine/engine.go

@@ -18,7 +18,7 @@ var ErrTemplateIsEmpty = fmt.Errorf("template is empty")
 type Vars map[string]any
 
 type Engine struct {
-	baseTemplate *template.Template
+	fm template.FuncMap
 }
 
 func New() *Engine {
@@ -27,10 +27,14 @@ func New() *Engine {
 	fm["wraptmpl"] = wraptmpl
 
 	return &Engine{
-		baseTemplate: template.New("scaffold").Funcs(fm),
+		fm: fm,
 	}
 }
 
+func (e *Engine) parse(tmpl string) (*template.Template, error) {
+	return template.New("scaffold").Funcs(e.fm).Parse(tmpl)
+}
+
 func isTemplate(s string) bool {
 	return strings.Contains(s, "{{")
 }
@@ -40,7 +44,7 @@ func (e *Engine) TmplString(str string, vars any) (string, error) {
 		return str, nil
 	}
 
-	tmpl, err := e.baseTemplate.Parse(str)
+	tmpl, err := e.parse(str)
 	if err != nil {
 		log.Err(err).Msg("failed to parse template")
 		return "", err
@@ -73,7 +77,7 @@ func (e *Engine) Factory(reader io.Reader) (*template.Template, error) {
 		return nil, ErrTemplateIsEmpty
 	}
 
-	return e.baseTemplate.Parse(string(out))
+	return e.parse(string(out))
 }
 
 func (e *Engine) Render(w io.Writer, tmpl *template.Template, vars any) error {

app/scaffold/render_funcs.go

@@ -294,6 +294,12 @@ func RenderRWFS(eng *engine.Engine, args *RWFSArgs, vars engine.Vars) error {
 			return nil
 		}
 
+		// Skip whitespace files
+		if len(strings.TrimSpace(buff.String())) == 0 {
+			_ = f.Close()
+			return nil
+		}
+
 		// Ensure the directory exists
 		err = args.WriteFS.MkdirAll(filepath.Dir(outpath), os.ModePerm)
 		if err != nil {