add wireexample;

wireexample/cmd/example_01/main.go

@@ -0,0 +1,29 @@
+// 展示 wire 的两种 mock 实现
+
+package main
+
+import "fmt"
+
+func main() {
+	approachA()
+	approachB()
+}
+
+// approach A:
+//   - 需要 mock 的对象定义成接口, 真正的实现和 mock 分别实现接口;
+//   - injector 函数使用 接口类型参数, 测试时传入 mock 对象;
+func approachA() {
+	rander := &MockRander{}
+	guess := InjectGuessWithoutMock(rander)
+	rander.Value = 1
+	fmt.Println("approachA:", guess.Guess(10))
+}
+
+// approach B:
+//   - mock 和 真正的实现分别定义到两组 injector 中, injector 提供1个对象包含要测试的对象和 mock;
+//   - 测试时调用 mock injector 返回对象(包含要测试的对象和 mock);
+func approachB() {
+	guessWithMock := InjectMockGuess()
+	guessWithMock.Mock.Value = 1
+	fmt.Println("approachB:", guessWithMock.Guess.Guess(10))
+}

wireexample/cmd/example_01/provider.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/google/wire"
+)
+
+type Rander interface {
+	Rand() int
+}
+
+type DefaultRander struct{}
+
+func (r *DefaultRander) Rand() int {
+	return rand.Int()
+}
+
+func NewRander() *DefaultRander {
+	return &DefaultRander{}
+}
+
+type MockRander struct {
+	Value int
+}
+
+func (r *MockRander) Rand() int {
+	return r.Value
+}
+
+type Guess struct {
+	rander Rander
+}
+
+func (g *Guess) Guess(guess int) string {
+	return fmt.Sprintf("you guess %d, real number is %d", guess, g.rander.Rand())
+}
+
+func NewGuess(rander Rander) *Guess {
+	return &Guess{
+		rander: rander,
+	}
+}
+
+type GuessWithMock struct {
+	Guess *Guess
+	Mock  *MockRander
+}
+
+var GuessProviderSetWithoutMock = wire.NewSet(NewGuess)
+
+var GuessProviderSet = wire.NewSet(
+	NewRander,
+	NewGuess,
+	wire.Bind(new(Rander), new(*DefaultRander)),
+)
+
+var MockGuessProviderSet = wire.NewSet(
+	wire.Struct(new(MockRander)),
+	NewGuess,
+	wire.Bind(new(Rander), new(*MockRander)),
+	wire.Struct(new(GuessWithMock), "*"),
+)

wireexample/cmd/example_01/wire.go

@@ -0,0 +1,20 @@
+//go:build wireinject
+
+package main
+
+import "github.com/google/wire"
+
+// Approach A
+func InjectGuessWithoutMock(rander Rander) *Guess {
+	panic(wire.Build(GuessProviderSetWithoutMock))
+}
+
+// Approach B
+func InjectRealGuess() *Guess {
+	panic(wire.Build(GuessProviderSet))
+}
+
+// Approach B
+func InjectMockGuess() *GuessWithMock {
+	panic(wire.Build(MockGuessProviderSet))
+}

wireexample/cmd/example_01/wire_gen.go

@@ -0,0 +1,33 @@
+// Code generated by Wire. DO NOT EDIT.
+
+//go:generate go run github.com/google/wire/cmd/wire
+//go:build !wireinject
+// +build !wireinject
+
+package main
+
+// Injectors from wire.go:
+
+// Approach A
+func InjectGuessWithoutMock(rander Rander) *Guess {
+	guess := NewGuess(rander)
+	return guess
+}
+
+// Approach B
+func InjectRealGuess() *Guess {
+	defaultRander := NewRander()
+	guess := NewGuess(defaultRander)
+	return guess
+}
+
+// Approach B
+func InjectMockGuess() *GuessWithMock {
+	mockRander := &MockRander{}
+	guess := NewGuess(mockRander)
+	guessWithMock := &GuessWithMock{
+		Guess: guess,
+		Mock:  mockRander,
+	}
+	return guessWithMock
+}