README.md

Demo

This demo shows how rewrite and mock works.

Run:

go run github.com/xhd2015/go-mock run ./

Output:

main begin
calling: github.com/xhd2015/go-mock/example/demo/biz.Run
mock biz.Run
calling: github.com/xhd2015/go-mock/example/demo/biz.Status.Run
biz.Status.Run: 2

In biz/biz.go we defined 2 functions, one for package-level and the other for a named type:

package biz

func Run(ctx context.Context, status int, _ string) (int, error) {
	fmt.Printf("biz.Run: %v\n", status)
	return 0, nil
}

type Status int
func (c Status) Run(ctx context.Context, status int, _ string) (int, error) {
	fmt.Printf("biz.Status.Run: %v\n", status)
	return 0, nil
}

In main.go we make call to these 2 functions defiend in biz/biz.go, with just some mock setup:

package main

import (
	"context"
	"fmt"

	"github.com/xhd2015/go-mock/example/demo/biz"
	mock_biz "github.com/xhd2015/go-mock/example/demo/test/mock_gen/biz"
	"github.com/xhd2015/go-mock/mock"
)

func main() {
	fmt.Printf("main begin\n")

	// add general function interceptor
	mock.AddInterceptor(func(ctx context.Context, stubInfo *mock.StubInfo, inst, req, resp interface{}, f mock.Filter, next func(ctx context.Context) error) error {
		fmt.Printf("calling: %v\n", stubInfo)
		return next(ctx)
	})

	// associate mock into ctx
	ctx := context.Background()
	ctx = mock_biz.Setup(ctx, func(m *mock_biz.M) {
		m.Run = func(ctx context.Context, status int, _ string) (int, error) {
			fmt.Printf("mock biz.Run\n")
			return 123456, nil
		}
	})

	// call biz.Run
	biz.Run(ctx, 1, "A")

	// call biz.Status.Run
	status := biz.Status(1)
	status.Run(ctx, 2, "B")
}

We get the following output explained:

main begin            --> main begin
calling: github.com/xhd2015/go-mock/example/demo/biz.Run   --> printed by our general interceptor
mock biz.Run          --> function mocked
calling: github.com/xhd2015/go-mock/example/demo/biz.Status.Run   --> printed by our general interceptor
biz.Status.Run: 2     --> function not mocked

The interceptor is very powerful, just like interceptor in usual RCP frameworks like gRPC. By adding interceptor we can do things in a generalized way, this would amazingly change the game of mock.

Verify mock content

You can verify the generated content via:

go run github.com/xhd2015/go-mock print ./biz/biz.go

Original content:

package biz

import (
	"context"
	"fmt"
)

func Run(ctx context.Context, status int, _ string) (int, error) {
	fmt.Printf("biz.Run: %v\n", status)
	return 0, nil
}

type Status int

func (c Status) Run(ctx context.Context, status int, _ string) (int, error) {
	fmt.Printf("biz.Status.Run: %v\n", status)
	return 0, nil
}

Output: rewrite content

// rewrite of /Users/x/gopath/src/github.com/xhd2015/go-mock/example/demo/biz/biz.go:
package biz;import _mock "github.com/xhd2015/go-mock/mock"

import (
        "context"
        "fmt"
)

func Run(ctx context.Context, status int, unused_2 string) (Resp_0 int, err error) {var _mockreq = struct{Status int `json:"status"`;Unused_2 string `json:"unused_2"`;}{Status: status,Unused_2: unused_2};var _mockresp struct{Resp_0 int `json:"Resp_0"`;};err = _mock.TrapFunc(ctx,&_mock.StubInfo{PkgName:"github.com/xhd2015/go-mock/example/demo/biz",Owner:"",OwnerPtr:false,Name:"Run"}, nil, &_mockreq, &_mockresp,_mockRun,false,true,true);Resp_0 = _mockresp.Resp_0;return;}; func _mockRun(ctx context.Context, status int, _ string)(int, error){
        fmt.Printf("biz.Run: %v\n", status)
        return 0, nil
}

type Status int

func (c Status) Run(ctx context.Context, status int, unused_2 string) (Resp_0 int, err error) {var _mockreq = struct{Status int `json:"status"`;Unused_2 string `json:"unused_2"`;}{Status: status,Unused_2: unused_2};var _mockresp struct{Resp_0 int `json:"Resp_0"`;};err = _mock.TrapFunc(ctx,&_mock.StubInfo{PkgName:"github.com/xhd2015/go-mock/example/demo/biz",Owner:"Status",OwnerPtr:false,Name:"Run"}, c, &_mockreq, &_mockresp,_mockStatus_Run,true,true,true);Resp_0 = _mockresp.Resp_0;return;}; func _mockStatus_Run(c Status,ctx context.Context, status int, _ string)(int, error){
        fmt.Printf("biz.Status.Run: %v\n", status)
        return 0, nil
}

type-safe mock stub:

// mock of /Users/x/gopath/src/github.com/xhd2015/go-mock/example/demo/biz/biz.go:
// Code generated by go-mock; DO NOT EDIT.

package biz

import (
    "context"
    "github.com/xhd2015/go-mock/example/demo/biz"
    _mock "github.com/xhd2015/go-mock/mock"
)

const _SKIP_MOCK = true
const FULL_PKG_NAME = "github.com/xhd2015/go-mock/example/demo/biz"

func Setup(ctx context.Context,setup func(m *M)) context.Context {
    m:=M{}
    setup(&m)
    return _mock.WithMockSetup(ctx,FULL_PKG_NAME,m)
}


type M struct {
    Run func(ctx context.Context, status int, _ string)(int, error)
    Status struct{
            Run func(c biz.Status,ctx context.Context, status int, _ string)(int, error)
    }
}

/* prodives quick link */
var _ = func() { type Pair [2]interface{};e:=M{};_ = map[string]interface{}{
    "Run": Pair{e.Run,biz.Run},
    "Status":map[string]interface{}{
             "Run": Pair{e.Status.Run,((*biz.Status)(nil)).Run},
    },
}}