feat: add defer

Author: sysulq

example_test.go

@@ -321,3 +321,23 @@ func Example_testWithKoanf() {
 	// Hello, World!
 	// helloWorld shutdown
 }
+
+// This example demonstrates how to use [kod.RunTest] to run a test function with a defer function.
+func Example_testWithDefer() {
+	kod.RunTest(&testing.T{}, func(ctx context.Context, app *helloworld.App) {
+		k := kod.FromContext(ctx)
+		k.Defer("test", func(ctx context.Context) error {
+			fmt.Println("Defer called")
+			return nil
+		})
+
+		fmt.Println(app.Config().Name)
+		app.HelloWorld.Get().SayHello(ctx)
+	})
+	// Output:
+	// helloWorld init
+	// kod
+	// Hello, World!
+	// Defer called
+	// helloWorld shutdown
+}

kod.go

@@ -386,6 +386,11 @@ func (k *Kod) Config() kodConfig {
 	return k.config
 }
 
+// Defer adds a hook function to the Kod instance.
+func (k *Kod) Defer(name string, fn func(context.Context) error) {
+	k.hooker.Add(hooks.HookFunc{Name: name, Fn: fn})
+}
+
 // unmarshalConfig sets the configuration for the Kod instance.
 func (k *Kod) unmarshalConfig(key string, out interface{}) error {
 	err := defaults.Set(out)