🐛 fix: mounted app views (#1749)

* Fix mounted app views.

* Cleaner structure.

Co-authored-by: RW <rene@gofiber.io>

* remove unnecessary lines.

* Add test case for group-with-mount, remove unnecessary lines.

Co-authored-by: RW <rene@gofiber.io>

.github/testdata/template/hello_world.gohtml

@@ -0,0 +1 @@
+<h1>Hello {{ .Name }}!</h1>

app.go

@@ -111,8 +111,9 @@ type App struct {
 	getBytes func(s string) (b []byte)
 	// Converts byte slice to a string
 	getString func(b []byte) string
-	// mount prefix -> error handler
-	errorHandlers map[string]ErrorHandler
+
+	// Mounted and main apps
+	appList map[string]*App
 }
 
 // Config is a struct holding the server settings.
@@ -460,10 +461,10 @@ func New(config ...Config) *App {
 			},
 		},
 		// Create config
-		config:        Config{},
-		getBytes:      utils.UnsafeBytes,
-		getString:     utils.UnsafeString,
-		errorHandlers: make(map[string]ErrorHandler),
+		config:    Config{},
+		getBytes:  utils.UnsafeBytes,
+		getString: utils.UnsafeString,
+		appList:   make(map[string]*App),
 	}
 	// Override config if provided
 	if len(config) > 0 {
@@ -515,6 +516,9 @@ func New(config ...Config) *App {
 		app.handleTrustedProxy(ipAddress)
 	}
 
+	// Init appList
+	app.appList[""] = app
+
 	// Init app
 	app.init()
 
@@ -544,20 +548,18 @@ func (app *App) handleTrustedProxy(ipAddress string) {
 // to be invoked on errors that happen within the prefix route.
 func (app *App) Mount(prefix string, fiber *App) Router {
 	stack := fiber.Stack()
+	prefix = strings.TrimRight(prefix, "/")
 	for m := range stack {
 		for r := range stack[m] {
 			route := app.copyRoute(stack[m][r])
 			app.addRoute(route.Method, app.addPrefixToRoute(prefix, route))
 		}
 	}
 
-	// Save the fiber's error handler and its sub apps
-	prefix = strings.TrimRight(prefix, "/")
-	if fiber.config.ErrorHandler != nil {
-		app.errorHandlers[prefix] = fiber.config.ErrorHandler
-	}
-	for mountedPrefixes, errHandler := range fiber.errorHandlers {
-		app.errorHandlers[prefix+mountedPrefixes] = errHandler
+	// Support for configs of mounted-apps and sub-mounted-apps
+	for mountedPrefixes, subApp := range fiber.appList {
+		app.appList[prefix+mountedPrefixes] = subApp
+		subApp.init()
 	}
 
 	atomic.AddUint32(&app.handlersCount, fiber.handlersCount)
@@ -1002,11 +1004,11 @@ func (app *App) ErrorHandler(ctx *Ctx, err error) error {
 		mountedPrefixParts int
 	)
 
-	for prefix, errHandler := range app.errorHandlers {
-		if strings.HasPrefix(ctx.path, prefix) {
+	for prefix, subApp := range app.appList {
+		if strings.HasPrefix(ctx.path, prefix) && prefix != "" {
 			parts := len(strings.Split(prefix, "/"))
 			if mountedPrefixParts <= parts {
-				mountedErrHandler = errHandler
+				mountedErrHandler = subApp.config.ErrorHandler
 				mountedPrefixParts = parts
 			}
 		}

ctx.go

@@ -1082,18 +1082,28 @@ func (c *Ctx) Render(name string, bind interface{}, layouts ...string) error {
 
 	}
 
-	if c.app.config.Views != nil {
-		// Render template based on global layout if exists
-		if len(layouts) == 0 && c.app.config.ViewsLayout != "" {
-			layouts = []string{
-				c.app.config.ViewsLayout,
+	rendered := false
+	for prefix, app := range c.app.appList {
+		if prefix == "" || strings.Contains(c.OriginalURL(), prefix) {
+			if len(layouts) == 0 && app.config.ViewsLayout != "" {
+				layouts = []string{
+					app.config.ViewsLayout,
+				}
+			}
+
+			// Render template from Views
+			if app.config.Views != nil {
+				if err := app.config.Views.Render(buf, name, bind, layouts...); err != nil {
+					return err
+				}
+
+				rendered = true
+				break
 			}
 		}
-		// Render template from Views
-		if err := c.app.config.Views.Render(buf, name, bind, layouts...); err != nil {
-			return err
-		}
-	} else {
+	}
+
+	if !rendered {
 		// Render raw template using 'name' as filepath if no engine is set
 		var tmpl *template.Template
 		if _, err = readContent(buf, name); err != nil {
@@ -1109,6 +1119,7 @@ func (c *Ctx) Render(name string, bind interface{}, layouts ...string) error {
 			return err
 		}
 	}
+
 	// Set Content-Type to text/html
 	c.fasthttp.Response.Header.SetContentType(MIMETextHTMLCharsetUTF8)
 	// Set rendered template to body

ctx_test.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/gofiber/fiber/v2/internal/bytebufferpool"
 	"github.com/gofiber/fiber/v2/internal/storage/memory"
+	"github.com/gofiber/fiber/v2/internal/template/html"
 	"github.com/gofiber/fiber/v2/utils"
 	"github.com/valyala/fasthttp"
 )
@@ -2049,6 +2050,59 @@ func Test_Ctx_Render(t *testing.T) {
 	err = c.Render("./.github/testdata/template-invalid.html", nil)
 	utils.AssertEqual(t, false, err == nil)
 }
+
+// go test -run Test_Ctx_Render_Mount
+func Test_Ctx_Render_Mount(t *testing.T) {
+	t.Parallel()
+
+	sub := New(Config{
+		Views: html.New("./.github/testdata/template", ".gohtml"),
+	})
+
+	sub.Get("/:name", func(ctx *Ctx) error {
+		return ctx.Render("hello_world", Map{
+			"Name": ctx.Params("name"),
+		})
+	})
+
+	app := New()
+	app.Mount("/hello", sub)
+
+	resp, err := app.Test(httptest.NewRequest(MethodGet, "/hello/a", nil))
+	utils.AssertEqual(t, StatusOK, resp.StatusCode, "Status code")
+	utils.AssertEqual(t, nil, err, "app.Test(req)")
+
+	body, err := ioutil.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, "<h1>Hello a!</h1>", string(body))
+}
+
+func Test_Ctx_Render_MountGroup(t *testing.T) {
+	t.Parallel()
+
+	micro := New(Config{
+		Views: html.New("./.github/testdata/template", ".gohtml"),
+	})
+
+	micro.Get("/doe", func(c *Ctx) error {
+		return c.Render("hello_world", Map{
+			"Name": "doe",
+		})
+	})
+
+	app := New()
+	v1 := app.Group("/v1")
+	v1.Mount("/john", micro)
+
+	resp, err := app.Test(httptest.NewRequest(MethodGet, "/v1/john/doe", nil))
+	utils.AssertEqual(t, nil, err, "app.Test(req)")
+	utils.AssertEqual(t, 200, resp.StatusCode, "Status code")
+
+	body, err := ioutil.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, "<h1>Hello doe!</h1>", string(body))
+}
+
 func Test_Ctx_RenderWithoutLocals(t *testing.T) {
 	t.Parallel()
 	app := New(Config{

group.go

@@ -32,13 +32,11 @@ func (grp *Group) Mount(prefix string, fiber *App) Router {
 		}
 	}
 
-	// Save the fiber's error handler and its sub apps
+	// Support for configs of mounted-apps and sub-mounted-apps
 	groupPath = strings.TrimRight(groupPath, "/")
-	if fiber.config.ErrorHandler != nil {
-		grp.app.errorHandlers[groupPath] = fiber.config.ErrorHandler
-	}
-	for mountedPrefixes, errHandler := range fiber.errorHandlers {
-		grp.app.errorHandlers[groupPath+mountedPrefixes] = errHandler
+	for mountedPrefixes, subApp := range fiber.appList {
+		grp.app.appList[groupPath+mountedPrefixes] = subApp
+		subApp.init()
 	}
 
 	atomic.AddUint32(&grp.app.handlersCount, fiber.handlersCount)