Add --test flag to test for errors without actually reloading

Author: brechtvl

cmd/manager.go

@@ -54,6 +54,10 @@ var (
 			cli.BoolFlag{
 				Name: "debug",
 			},
+			cli.BoolFlag{
+				Name:  "test",
+				Usage: "Test templates for errors without actually reloading",
+			},
 		},
 		Action: runReloadTemplates,
 	}
@@ -131,7 +135,7 @@ func runReloadTemplates(c *cli.Context) error {
 	defer cancel()
 
 	setup(ctx, c.Bool("debug"))
-	extra := private.ReloadTemplates(ctx)
+	extra := private.ReloadTemplates(ctx, c.Bool("test"))
 	return handleCliResponseExtra(extra)
 }
 

modules/private/manager.go

@@ -30,8 +30,8 @@ func Restart(ctx context.Context) ResponseExtra {
 }
 
 // ReloadTemplates calls the internal reload-templates function
-func ReloadTemplates(ctx context.Context) ResponseExtra {
-	reqURL := setting.LocalURL + "api/internal/manager/reload-templates"
+func ReloadTemplates(ctx context.Context, test bool) ResponseExtra {
+	reqURL := setting.LocalURL + fmt.Sprintf("api/internal/manager/reload-templates?test=%t", test)
 	req := newInternalRequest(ctx, reqURL, "POST")
 	return requestJSONUserMsg(req, "Reloaded")
 }

modules/templates/htmlrenderer.go

@@ -62,7 +62,7 @@ func (h *HTMLRender) TemplateLookup(name string) (TemplateExecutor, error) {
 	return tmpls.Executor(name, NewFuncMap())
 }
 
-func (h *HTMLRender) CompileTemplates() error {
+func (h *HTMLRender) CompileTemplates(test bool) error {
 	assets := AssetFS()
 	extSuffix := ".tmpl"
 	tmpls := scopedtmpl.NewScopedTemplate()
@@ -85,6 +85,9 @@ func (h *HTMLRender) CompileTemplates() error {
 			return err
 		}
 	}
+	if test {
+		return nil
+	}
 	tmpls.Freeze()
 	h.templates.Store(tmpls)
 	return nil
@@ -96,9 +99,11 @@ func HTMLRenderer() *HTMLRender {
 	return htmlRender
 }
 
-func ReloadHTMLTemplates() error {
-	if err := htmlRender.CompileTemplates(); err != nil {
-		log.Error("Template error: %v\n%s", err, log.Stack(2))
+func ReloadHTMLTemplates(test bool) error {
+	if err := htmlRender.CompileTemplates(test); err != nil {
+		if !test {
+			log.Error("Template error: %v\n%s", err, log.Stack(2))
+		}
 		return err
 	}
 	return nil
@@ -112,7 +117,7 @@ func initHTMLRenderer() {
 	log.Debug("Creating %s HTML Renderer", rendererType)
 
 	htmlRender = &HTMLRender{}
-	if err := htmlRender.CompileTemplates(); err != nil {
+	if err := htmlRender.CompileTemplates(false); err != nil {
 		p := &templateErrorPrettier{assets: AssetFS()}
 		wrapFatal(p.handleFuncNotDefinedError(err))
 		wrapFatal(p.handleUnexpectedOperandError(err))
@@ -123,7 +128,7 @@ func initHTMLRenderer() {
 
 	if !setting.IsProd {
 		go AssetFS().WatchLocalChanges(graceful.GetManager().ShutdownContext(), func() {
-			_ = ReloadHTMLTemplates()
+			_ = ReloadHTMLTemplates(false)
 		})
 	}
 }

routers/private/manager.go

@@ -21,7 +21,8 @@ import (
 
 // ReloadTemplates reloads all the templates
 func ReloadTemplates(ctx *context.PrivateContext) {
-	err := templates.ReloadHTMLTemplates()
+	test := ctx.FormBool("test")
+	err := templates.ReloadHTMLTemplates(test)
 	if err != nil {
 		ctx.JSON(http.StatusInternalServerError, private.Response{
 			UserMsg: fmt.Sprintf("Template error: %v", err),