feat(helper): Added Tap/With/When method

Signed-off-by: Flc゛ <four_leaf_clover@foxmail.com>

helper/README.md

@@ -0,0 +1,52 @@
+# helper
+
+## Example
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"github.com/go-kratos-ecosystem/components/v2/helper"
+)
+
+type User struct {
+	Name string
+	Age  int
+}
+
+func main() {
+	user := &User{Name: "foo"}
+
+	// Tap
+	user = helper.Tap(user, func(u *User) {
+		u.Name = "bar"
+		u.Age = 18
+	})
+	fmt.Println(user)
+	// output:
+	// &{bar 18}
+
+	// With
+	user = helper.With(user, func(u *User) *User {
+		u.Name = "baz"
+		u.Age = 19
+		return u
+	})
+	fmt.Println(user)
+	// output:
+	// &{baz 19}
+
+	// When
+	user = helper.When(user, true, func(u *User) *User {
+		u.Name = "Flc"
+		u.Age = 20
+		return u
+	})
+
+	fmt.Println(user)
+	// output:
+	// &{Flc 20}
+}
+```

helper/helper.go

@@ -0,0 +1,29 @@
+package helper
+
+func Tap[T any](value T, callbacks ...func(T)) T {
+	for _, callback := range callbacks {
+		if callback != nil {
+			callback(value)
+		}
+	}
+
+	return value
+}
+
+func With[T any](value T, callbacks ...func(T) T) T {
+	for _, callback := range callbacks {
+		if callback != nil {
+			value = callback(value)
+		}
+	}
+
+	return value
+}
+
+func When[T any](value T, condition bool, callbacks ...func(T) T) T {
+	if condition {
+		return With(value, callbacks...)
+	}
+
+	return value
+}

helper/helper_test.go

@@ -0,0 +1,87 @@
+package helper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type foo struct {
+	Name string
+	Age  int
+}
+
+func TestTap_Struct(t *testing.T) {
+	f := &foo{Name: "foo"}
+
+	assert.Equal(t, "foo", f.Name)
+	assert.Equal(t, 0, f.Age)
+
+	f = Tap(f, func(f *foo) {
+		f.Name = "bar"
+		f.Age = 18
+	})
+	assert.Equal(t, "bar", f.Name)
+	assert.Equal(t, 18, f.Age)
+}
+
+func TestTap_Int(t *testing.T) {
+	f := new(int)
+	*f = 10
+
+	assert.Equal(t, 10, *f)
+	f = Tap(f, func(f *int) {
+		*f = 20
+	})
+	assert.Equal(t, 20, *f)
+
+	b := 10
+	assert.Equal(t, 10, b)
+	b = Tap(b, func(f int) {
+		f = 20
+	})
+	assert.Equal(t, 10, b)
+
+	b2 := Tap(&b, func(f *int) {
+		*f = 20
+	})
+	assert.Equal(t, 20, *b2)
+}
+
+func TestWith(t *testing.T) {
+	f := &foo{Name: "foo"}
+
+	assert.Equal(t, "foo", f.Name)
+	assert.Equal(t, 0, f.Age)
+
+	f2 := With(f, func(f *foo) *foo {
+		f.Name = "bar"
+		f.Age = 18
+		return f
+	})
+	assert.Equal(t, "bar", f2.Name)
+	assert.Equal(t, 18, f2.Age)
+}
+
+func TestWhen(t *testing.T) {
+	f := &foo{Name: "foo"}
+
+	assert.Equal(t, "foo", f.Name)
+	assert.Equal(t, 0, f.Age)
+
+	f2 := When(f, true, func(f *foo) *foo {
+		f.Name = "bar"
+		f.Age = 18
+		return f
+	})
+	assert.Equal(t, "bar", f2.Name)
+	assert.Equal(t, 18, f2.Age)
+
+	f3 := When(f, false, func(f *foo) *foo {
+		f.Name = "baz"
+		f.Age = 20
+		return f
+	})
+	assert.Equal(t, "bar", f3.Name)
+	assert.Equal(t, 18, f3.Age)
+}

utils/utils.go

@@ -5,6 +5,7 @@ import (
 	"reflect"
 )
 
+// Deprecated: use helper.Tap instead
 // Tap calls the given callback with the given value then returns the value.
 func Tap(value interface{}, callbacks ...func(interface{})) interface{} {
 	for _, callback := range callbacks {
@@ -14,6 +15,7 @@ func Tap(value interface{}, callbacks ...func(interface{})) interface{} {
 	return value
 }
 
+// Deprecated: use helper.With instead
 // With calls the given callbacks with the given value then return the value.
 func With(value interface{}, callbacks ...func(interface{}) interface{}) interface{} {
 	for _, callback := range callbacks {