xgo：一个基于 IR 重写的 golang mock 库

[xhd2015]

最近基于工作需要，在使用了 gomonkey 遇到很多问题之后，并且也担心基于 Assembly 的方式对未来单测维护的不可持续性，开发了 xgo 。

xgo 基于 IR 中间码重写，更加贴近源代码而不是机器码。所以兼容性比 Assembly 要好很多，功能也更强。

下面是一个简单的示例:

package demo

import (
	"context"
	"testing"

	"github.com/xhd2015/xgo/runtime/core"
	"github.com/xhd2015/xgo/runtime/mock"
)

func MyFunc() string {
	return "my func"
}
func TestFuncMock(t *testing.T) {
	mock.Mock(MyFunc, func(ctx context.Context, fn *core.FuncInfo, args core.Object, results core.Object) error {
		results.GetFieldIndex(0).Set("mock func")
		return nil
	})
	text := MyFunc()
	if text != "mock func" {
		t.Fatalf("expect MyFunc() to be 'mock func', actual: %s", text)
	}
}

欢迎大家使用和提意见

项目地址 https://github.com/xhd2015/xgo

[mightybruce]

行，关注了。

[xhd2015]

说明一下：该 mock 不需要基于接口进行 monkey ，开箱可用😃

[oceana]

点个赞

[xhd2015]

@oceana 感谢，可以一起交流😌

[sophos]

有点意思，和我这个项目的功能有点类似，不过实现思路不太一样 :-)

https://github.com/go-kod/kod

[xhd2015]

@sophos 目标不一样，这个是单元测试场景，主打无代码侵入，无代码生成

[sophos]

@xhd2015 嗯，我这个是为了优化代码模块设计，同时解决单元测试标准化的问题

不过个人感觉单元测试的最佳实践还是 mock interface ，patch 不够直观

[xhd2015]

@sophos 哈哈，我持相反的看法

[huyujievip]

看文档是支持泛型函数指定类型 mock 的，但是自己尝试下来确不支持，求解答，谢谢

报错：

panic: func not instrumented by xgo, see https://github.com/xhd2015/xgo/tree/master/doc/ERR_NOT_INSTRUMENTED.md: demo_test.MyFuncT[int]



```go
package demo_test

import (
"testing"

"github.com/xhd2015/xgo/runtime/mock"
)

func MyFunc() string {
return "my func"
}

func MyFuncT[T any](t T) T {
return t
}

var MyFuncTInt = MyFuncT[int]

func TestFuncMock(t *testing.T) {
mock.Patch(MyFunc, func() string {
return "mock func"
})
text := MyFunc()
if text != "mock func" {
t.Fatalf("expect MyFunc() to be 'mock func', actual: %s", text)
}
}

func TestFuncMockIntA(t *testing.T) {
mock.Patch(MyFuncTInt, func(t int) int {
return 2
})
text := MyFuncTInt(1)
if text != 2 {
t.Fatalf("expect intA() to be '2', actual: %d", text)
}
}

func TestFuncMockT(t *testing.T) {
println("111111")
mock.Patch(MyFuncTInt, func(t int) int {
println("333333")
return 2
})
println("222222")
text := MyFuncTInt(1)
if text != 2 {
t.Fatalf("expect MyFuncT() to be '2', actual: %d", text)
}
}
```

```console
xgo test -v ./
=== RUN TestFuncMock
--- PASS: TestFuncMock (0.00s)
=== RUN TestFuncMockIntA
--- FAIL: TestFuncMockIntA (0.00s)
panic: func not instrumented by xgo, see https://github.com/xhd2015/xgo/tree/master/doc/ERR_NOT_INSTRUMENTED.md: demo_test.MyFuncT[int] [recovered]
panic: func not instrumented by xgo, see https://github.com/xhd2015/xgo/tree/master/doc/ERR_NOT_INSTRUMENTED.md: demo_test.MyFuncT[int]

goroutine 19 [running]:
testing.tRunner.func1.2({0x100c85be0, 0x140000a0ac0})
/Users/lula/.xgo/go-instrument/go1.24.2_op_ho_Ce_go_1._li_9f53f045/go1.24.2/src/testing/testing.go:1734 +0x1ac
testing.tRunner.func1()
/Users/lula/.xgo/go-instrument/go1.24.2_op_ho_Ce_go_1._li_9f53f045/go1.24.2/src/testing/testing.go:1737 +0x334
panic({0x100c85be0?, 0x140000a0ac0?})
/Users/lula/.xgo/go-instrument/go1.24.2_op_ho_Ce_go_1._li_9f53f045/go1.24.2/src/runtime/panic.go:792 +0x124
github.com/xhd2015/xgo/runtime/internal/trap.Inspect({0x100c75480, 0x100cb6540})
/Users/lula/Library/Go/pkg/mod/github.com/xhd2015/xgo/[email protected]/internal/trap/inspect.go:68 +0x530
github.com/xhd2015/xgo/runtime/internal/trap.pushMockReplacer({0x100c75480, 0x100cb6540}, {0x100c75480, 0x100cb6550})
/Users/lula/Library/Go/pkg/mod/github.com/xhd2015/xgo/[email protected]/internal/trap/mock.go:160 +0x3d0
github.com/xhd2015/xgo/runtime/internal/trap.PushMockReplacer(...)
/Users/lula/Library/Go/pkg/mod/github.com/xhd2015/xgo/[email protected]/internal/trap/mock.go:47
github.com/xhd2015/xgo/runtime/mock.Patch(...)
/Users/lula/Library/Go/pkg/mod/github.com/xhd2015/xgo/[email protected]/mock/patch.go:15
demo_test.TestFuncMockIntA(0x14000146380)
/Users/lula/Code/Go/go-learn/demo/demo_test.go:30 +0x14c
testing.tRunner(0x14000146380, 0x100cb5c50)
/Users/lula/.xgo/go-instrument/go1.24.2_op_ho_Ce_go_1._li_9f53f045/go1.24.2/src/testing/testing.go:1792 +0xe4
created by testing.(*T).Run in goroutine 1
/Users/lula/.xgo/go-instrument/go1.24.2_op_ho_Ce_go_1._li_9f53f045/go1.24.2/src/testing/testing.go:1851 +0x374
FAIL demo 0.259s
FAIL
```

[huyujievip]

第三个 Test 函数代码贴错了，纠正一下，下面的日志没有错

➜ demo xgo version
1.1.7
➜ demo xgo exec go version
go version go1.24.2 darwin/arm64
➜ demo go env
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOVERSION='go1.24.2'

```go
package demo_test

import (
"testing"

"github.com/xhd2015/xgo/runtime/mock"
)

func MyFunc() string {
return "my func"
}

func MyFuncT[T any](t T) T {
return t
}

var MyFuncTInt = MyFuncT[int]

func TestFuncMock(t *testing.T) {
mock.Patch(MyFunc, func() string {
return "mock func"
})
text := MyFunc()
if text != "mock func" {
t.Fatalf("expect MyFunc() to be 'mock func', actual: %s", text)
}
}

func TestFuncMockIntA(t *testing.T) {
mock.Patch(MyFuncTInt, func(t int) int {
return 2
})
text := MyFuncTInt(1)
if text != 2 {
t.Fatalf("expect intA() to be '2', actual: %d", text)
}
}

func TestFuncMockT(t *testing.T) {
println("111111")
mock.Patch(MyFuncT[int], func(t int) int {
println("333333")
return 2
})
println("222222")
text := MyFuncTInt(1)
if text != 2 {
t.Fatalf("expect MyFuncT() to be '2', actual: %d", text)
}
}
```

[xhd2015]

@huyujievip 感谢反馈，我今天看下这个问题。根据这个测试用例，范型是支持的 https://github.com/xhd2015/xgo/blob/master/runtime/test/mock/mock_generic/mock_generic_go1.20_above_should_success_test.go