🔥 feat: Add support for ReloadViews() (#3876)

Author: gaby

.markdownlint.yml

@@ -7,7 +7,8 @@ default: true
 extends: null
 
 # MD001/heading-increment : Heading levels should only increment by one level at a time : https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md001.md
-MD001: true
+# NOTE: The docs intentionally jump heading levels for anchor stability, so skip this rule globally.
+MD001: false
 
 # MD003/heading-style : Heading style : https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md003.md
 MD003:
@@ -244,5 +245,9 @@ MD055:
   # Table pipe style
   style: "consistent"
 
+# MD060/table-column-style : Table column style : https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md060.md
+# NOTE: Legacy docs rely on hand-crafted alignment, so disable this rule to avoid noisy warnings.
+MD060: false
+
 # MD056/table-column-count : Table column count : https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md056.md
 MD056: true

app.go

@@ -710,6 +710,27 @@ func (app *App) RegisterCustomBinder(customBinder CustomBinder) {
 	app.customBinders = append(app.customBinders, customBinder)
 }
 
+// ReloadViews reloads the configured view engine by invoking its Load method.
+// It returns an error if no view engine is configured or if reloading fails.
+func (app *App) ReloadViews() error {
+	app.mutex.Lock()
+	defer app.mutex.Unlock()
+
+	if app.config.Views == nil {
+		return ErrNoViewEngineConfigured
+	}
+
+	if viewValue := reflect.ValueOf(app.config.Views); viewValue.Kind() == reflect.Pointer && viewValue.IsNil() {
+		return ErrNoViewEngineConfigured
+	}
+
+	if err := app.config.Views.Load(); err != nil {
+		return fmt.Errorf("fiber: failed to reload views: %w", err)
+	}
+
+	return nil
+}
+
 // SetTLSHandler Can be used to set ClientHelloInfo when using TLS with Listener.
 func (app *App) SetTLSHandler(tlsHandler *TLSHandler) {
 	// Attach the tlsHandler to the config

app_test.go

@@ -1986,6 +1986,59 @@ func (invalidView) Load() error { return errors.New("invalid view") }
 
 func (invalidView) Render(io.Writer, string, any, ...string) error { panic("implement me") }
 
+type countingView struct {
+	loadErr error
+	loads   int
+}
+
+func (v *countingView) Load() error {
+	v.loads++
+	return v.loadErr
+}
+
+func (*countingView) Render(io.Writer, string, any, ...string) error { return nil }
+
+func Test_App_ReloadViews_Success(t *testing.T) {
+	t.Parallel()
+	view := &countingView{}
+	app := New(Config{Views: view})
+	initialLoads := view.loads
+
+	require.NoError(t, app.ReloadViews())
+	require.Equal(t, initialLoads+1, view.loads)
+
+	require.NoError(t, app.ReloadViews())
+	require.Equal(t, initialLoads+2, view.loads)
+}
+
+func Test_App_ReloadViews_Error(t *testing.T) {
+	t.Parallel()
+	wantedErr := errors.New("boom")
+	view := &countingView{loadErr: wantedErr}
+	app := New(Config{Views: view})
+
+	err := app.ReloadViews()
+	require.Error(t, err)
+	require.ErrorIs(t, err, wantedErr)
+}
+
+func Test_App_ReloadViews_NoEngine(t *testing.T) {
+	t.Parallel()
+	app := New()
+
+	err := app.ReloadViews()
+	require.ErrorIs(t, err, ErrNoViewEngineConfigured)
+}
+
+func Test_App_ReloadViews_InterfaceNilPointer(t *testing.T) {
+	t.Parallel()
+	var view *countingView
+	app := &App{config: Config{Views: view}}
+
+	err := app.ReloadViews()
+	require.ErrorIs(t, err, ErrNoViewEngineConfigured)
+}
+
 // go test -run Test_App_Init_Error_View
 func Test_App_Init_Error_View(t *testing.T) {
 	t.Parallel()

docs/api/app.md

@@ -25,6 +25,25 @@ Returns `b` unchanged when [`Immutable`](./fiber.md#immutable) is disabled or `b
 func (app *App) GetBytes(b []byte) []byte
 ```
 
+### ReloadViews
+
+Reloads the configured view engine on demand by calling its `Load` method. Use this helper in development workflows (e.g., file watchers or debug-only routes) to pick up template changes without restarting the server. Returns an error if no view engine is configured or reloading fails.
+
+```go title="Signature"
+func (app *App) ReloadViews() error
+```
+
+```go title="Example"
+app := fiber.New(fiber.Config{Views: engine})
+
+app.Get("/dev/reload", func(c fiber.Ctx) error {
+    if err := app.ReloadViews(); err != nil {
+        return err
+    }
+    return c.SendString("Templates reloaded")
+})
+```
+
 ## Routing
 
 import RoutingHandler from './../partials/routing/handler.md';

docs/whats_new.md

@@ -84,6 +84,7 @@ We have made several changes to the Fiber app, including:
 - **State**: Provides a global state for the application, which can be used to store and retrieve data across the application. Check out the [State](./api/state) method for further details.
 - **NewErrorf**: Allows variadic parameters when creating formatted errors.
 - **GetBytes / GetString**: Helpers that detach values only when `Immutable` is enabled and the data still references request or response buffers. Access via `c.App().GetString` and `c.App().GetBytes`.
+- **ReloadViews**: Lets you re-run the configured view engine's `Load()` logic at runtime, including guard rails for missing or nil view engines so development hot-reload hooks can refresh templates safely.
 
 #### Custom Route Constraints
 

error.go

@@ -18,6 +18,8 @@ var (
 	ErrNotRunning = errors.New("shutdown: server is not running")
 	// ErrHandlerExited is returned by App.Test if a handler panics or calls runtime.Goexit().
 	ErrHandlerExited = errors.New("runtime.Goexit() called in handler or server panic")
+	// ErrNoViewEngineConfigured indicates that a helper requiring a view engine was invoked without one configured.
+	ErrNoViewEngineConfigured = errors.New("fiber: no view engine configured")
 )
 
 // Fiber redirection errors