gomock 是 Google 开源的 Golang 测试框架。

GoMock is a mocking framework for the Go programming language.https://github.com/golang/mock

快速开始

安装 mockgen

To get the latest released version use:
Go version < 1.16

GO111MODULE=on go get github.com/golang/mock/mockgen@v1.6.0

Go 1.16+

go install github.com/golang/mock/mockgen@v1.6.0

定义好被测接口

// mockgen -source=./driver/navigator_driver.go -destination ./driver/navigator_driver_mock.go -package drivertype INavigatorDriver interface {Query(Ctx context.Context,SqlClient *sqlclient.SQLClient,sqlKey,sql string,searchOptions ...*engine.Option,) ([]map[string]interface{}, error)BatchGetProductInfoMap(Ctx context.Context,SqlClient *sqlclient.SQLClient,date string,ids []int64,entityFields []string,) (map[int64]interface{}, error)BatchGetBrandInfoMap(Ctx context.Context,SqlClient *sqlclient.SQLClient,date string,ids []int64,entityFields []string,) (map[int64]interface{}, error)
}type NavigatorDriver struct {
}

使用 mockgen 命令行自动生成 gomock代码

gomock通过mockgen命令生成包含mock对象的.go文件，其生成的mock对象具备mock+stub的强大功能.

mockgen -source=./driver/navigator_driver.go -destination ./driver/navigator_driver_mock.go -package driver

其中, navigator_driver_mock.go 是生成的 mock 代码.

代码目录:

类型关系:

生成的Mock Stub代码如下:

// Code generated by MockGen. DO NOT EDIT.
// Source: ./driver/navigator_driver.go// Package driver is a generated GoMock package.
package driverimport (context "context"reflect "reflect"...gomock "github.com/golang/mock/gomock"
)// MockINavigatorDriver is a mock of INavigatorDriver interface.
type MockINavigatorDriver struct {ctrl     *gomock.Controllerrecorder *MockINavigatorDriverMockRecorder
}// MockINavigatorDriverMockRecorder is the mock recorder for MockINavigatorDriver.
type MockINavigatorDriverMockRecorder struct {mock *MockINavigatorDriver
}// NewMockINavigatorDriver creates a new mock instance.
func NewMockINavigatorDriver(ctrl *gomock.Controller) *MockINavigatorDriver {mock := &MockINavigatorDriver{ctrl: ctrl}mock.recorder = &MockINavigatorDriverMockRecorder{mock}return mock
}// EXPECT returns an object that allows the caller to indicate expected use.
func (m *MockINavigatorDriver) EXPECT() *MockINavigatorDriverMockRecorder {return m.recorder
}// BatchGetBrandInfoList mocks base method.
func (m *MockINavigatorDriver) BatchGetBrandInfoMap(Ctx context.Context, SqlClient *sqlclient.SQLClient, date string, ids []int64, entityFields []string) (map[int64]interface{}, error) {m.ctrl.T.Helper()ret := m.ctrl.Call(m, "BatchGetBrandInfoMap", Ctx, SqlClient, date, ids, entityFields)ret0, _ := ret[0].(map[int64]interface{})ret1, _ := ret[1].(error)return ret0, ret1
}// BatchGetBrandInfoList indicates an expected call of BatchGetBrandInfoList.
func (mr *MockINavigatorDriverMockRecorder) BatchGetBrandInfoList(Ctx, SqlClient, date, ids, entityFields interface{}) *gomock.Call {mr.mock.ctrl.T.Helper()return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "BatchGetBrandInfoMap", reflect.TypeOf((*MockINavigatorDriver)(nil).BatchGetBrandInfoMap), Ctx, SqlClient, date, ids, entityFields)
}// BatchGetProductInfoList mocks base method.
func (m *MockINavigatorDriver) BatchGetProductInfoMap(Ctx context.Context, SqlClient *sqlclient.SQLClient, date string, ids []int64, entityFields []string) (map[int64]interface{}, error) {m.ctrl.T.Helper()ret := m.ctrl.Call(m, "BatchGetProductInfoMap", Ctx, SqlClient, date, ids, entityFields)ret0, _ := ret[0].(map[int64]interface{})ret1, _ := ret[1].(error)return ret0, ret1
}// BatchGetProductInfoList indicates an expected call of BatchGetProductInfoList.
func (mr *MockINavigatorDriverMockRecorder) BatchGetProductInfoList(Ctx, SqlClient, date, ids, entityFields interface{}) *gomock.Call {mr.mock.ctrl.T.Helper()return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "BatchGetProductInfoMap", reflect.TypeOf((*MockINavigatorDriver)(nil).BatchGetProductInfoMap), Ctx, SqlClient, date, ids, entityFields)
}// Query mocks base method.
func (m *MockINavigatorDriver) Query(Ctx context.Context, SqlClient *sqlclient.SQLClient, sqlKey, sql string, searchOptions ...*engine.Option) ([]map[string]interface{}, error) {m.ctrl.T.Helper()varargs := []interface{}{Ctx, SqlClient, sqlKey, sql}for _, a := range searchOptions {varargs = append(varargs, a)}ret := m.ctrl.Call(m, "Query", varargs...)ret0, _ := ret[0].([]map[string]interface{})ret1, _ := ret[1].(error)return ret0, ret1
}// Query indicates an expected call of Query.
func (mr *MockINavigatorDriverMockRecorder) Query(Ctx, SqlClient, sqlKey, sql interface{}, searchOptions ...interface{}) *gomock.Call {mr.mock.ctrl.T.Helper()varargs := append([]interface{}{Ctx, SqlClient, sqlKey, sql}, searchOptions...)return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Query", reflect.TypeOf((*MockINavigatorDriver)(nil).Query), varargs...)
}

测试代码实例

我们来 Mock 如下代码中的这个接口调用的返回值:

datasourceData, _ := navigatorDriver.Query(u.Ctx, u.Datasource.SqlClient, u.Datasource.SqlKey, navigatorSQL)

func (u *UIComponent) RenderDataTable() ([]map[string]interface{}, error) {bu, _ := json.Marshal(u)fmt.Println(string(bu))endTime := u.DateRangeFilter.EndDatedateType := u.DateRangeFilter.DaysType// 本周期时间dateStr := indexu.GetDateStr(endTime)// 1.fetch 数据源// 1.1 select 数据源字段 select columnscolumnNames := make([]string, 0)for _, e := range u.Datasource.Columns {columnNames = append(columnNames, e.Name)}// 1.2 数据源表datasourceTable := u.Datasource.TableName// 1.3 过滤条件 DateRangeFilter 是固定的whereExpr := buildWhereExpr(dateStr, dateType, u)datasourceCQL := alpha.NewCQL().SELECT(columnNames...).FROM(datasourceTable).WHERE(whereExpr).ORDERBY2(u.Datasource.DSOrderType, u.Datasource.DSOrderColumn).LIMIT2(u.Datasource.DSLimit)// 1.4 从数据源获取数据(领航者)// TODO MOCK, 线上用真实的 NavigatorQueryList 查询navigatorDriver := u.INavigatorDrivernavigatorSQL := datasourceCQL.Compile()logu.CtxInfo(u.Ctx, "RenderDataTable", "navigatorSQL: %v", navigatorSQL)datasourceData, _ := navigatorDriver.Query(u.Ctx, u.Datasource.SqlClient, u.Datasource.SqlKey, navigatorSQL)// 1.5 RSD 数据中添加排名字段信息 RankKeyif u.NeedRank {datasourceData = rocket.NewRSD2(datasourceData, u.Ctx, u.Datasource.SqlClient, u.INavigatorDriver).WithRank(u.RankKey, u.Datasource.Columns).Records}// 2.内存指标计算sqlite, _ := driver.InitSqlite(u.Ctx, map[string]interface{}{})// 2.1 从数据源返回数据中解析出列的元数据信息columns := ParseColumnsMeta(datasourceData)fmt.Println(columns)// 2.2 表名生成sqliteTableName := driver.GenerateUniqSQLiteTableName()// 2.3 建内存表driver.CreateTable(u.Ctx, sqliteTableName, columns, sqlite)// 2.4 同步数据到内存driver.InsertData(u.Ctx, sqliteTableName, datasourceData, columns, sqlite)// 2.5 内存数据条数校验count, _, _ := driver.Query(nil, fmt.Sprintf("select count(1) as count from %s", sqliteTableName), sqlite)if nums, err := convert.ToInt64E(count[0]["count"]); err == nil && nums <= 0 {return nil, fmt.Errorf("datasource empty")}// 2.6 内存计算非指标列var selectItem = []string{}for _, c := range u.Datasource.Columns { // 指标计算规则元数据信息if !c.IsDataIndex {cname := c.NameselectItem = append(selectItem, cname)}}// 2.7 内存计算指标列indexColumns := getIndexColumns(u.Datasource.Columns)// add incr select itemsfor _, column := range indexColumns {columnName := column.Namevar exp = fmt.Sprintf("IndexInfo(%s) as %s", columnName, columnName)selectItem = append(selectItem, exp)}// 2.8 CQL中添加排名信息 UDFif u.NeedRank {// Rank Key 是单独指定的,不是数据列的概念rankKey := u.RankKeyselectItem = append(selectItem, fmt.Sprintf("RankInfo(%s) as %s", rankKey, rankKey))}memCQL := alpha.NewCQL().SELECT(selectItem...).FROM(sqliteTableName)if u.DFLimit != nil && u.DFOffset != nil {memCQL = memCQL.LIMIT3(*u.DFLimit, *u.DFOffset)} else if u.DFLimit != nil && u.DFOffset == nil {memCQL = memCQL.LIMIT2(*u.DFLimit)}incrSQL := memCQL.Compile()fmt.Println(incrSQL)result, _, _ := driver.Query(u.Ctx, incrSQL, sqlite)rsd := rocket.NewRSD2(result, u.Ctx, u.Datasource.SqlClient, u.INavigatorDriver).UnmarshalIndexInfo(u.Datasource.Columns).UnmarshalRankInfo(u.NeedRank, u.RankKey).FillEntityInfoColumn(dateStr, u.Datasource.Columns)return rsd.Records, nil
}

接口定义

// mockgen -source=./driver/navigator_driver.go -destination ./driver/navigator_driver_mock.go -package drivertype INavigatorDriver interface {Query(Ctx context.Context,SqlClient *sqlclient.SQLClient,sqlKey,sql string,searchOptions ...*engine.Option,) ([]map[string]interface{}, error)BatchGetProductInfoMap(Ctx context.Context,SqlClient *sqlclient.SQLClient,date string,ids []int64,entityFields []string,) (map[int64]interface{}, error)BatchGetBrandInfoMap(Ctx context.Context,SqlClient *sqlclient.SQLClient,date string,ids []int64,entityFields []string,) (map[int64]interface{}, error)
}type NavigatorDriver struct {
}

mock 测试代码

关键代码行:

ctrl := gomock.NewController(t)defer ctrl.Finish()mockDriver := driver.NewMockINavigatorDriver(ctrl)// NavigatorQueryList 期望返回mockDriver.EXPECT().Query(ctx, SqlClient, "compass_strategy_chance_property_product_stats_di", gomock.Any(), gomock.Any()).Return(driver.MockNavigatorQueryListProductStats())

完整代码:

var (ctx       = context.Background()SqlClient = gomock.Any()
)func TestDataTableUIComponent(t *testing.T) {ctrl := gomock.NewController(t)defer ctrl.Finish()mockDriver := driver.NewMockINavigatorDriver(ctrl)// NavigatorQueryList 期望返回mockDriver.EXPECT().Query(ctx, SqlClient, "compass_strategy_chance_property_product_stats_di", gomock.Any(), gomock.Any()).Return(driver.MockNavigatorQueryListProductStats())mockDriver.EXPECT().BatchGetProductInfoList(ctx, SqlClient, gomock.Any(), gomock.Any(), gomock.Any()).Return(driver.MockNavigatorQueryListProudctMap())//mockDriver.//  EXPECT().//  BatchGetBrandInfoList(ctx, SqlClient, gomock.Any(), gomock.Any(), gomock.Any()).//  Return(driver.MockNavigatorQueryListBrandMap())// 初始化数据源columns := []datasource.Column{{Name: "date"},{Name: "days_type"},{Name: "stats_date"},{Name: "cate_id"},{Name: "cate_name"},{Name: "property_name"},{Name: "market_name"},{Name: "product_property_value"},{Name: "product_id", IsRowKey: true, NeedFillEntityInfo: true, EntityType: datasource.Product, EntityInfoColumnKey: "product_info"},{Name: "pay_amt", IsDataIndex: true},{Name: "pay_combo_cnt", IsDataIndex: true},}datasoure := &datasource.DataSource{TableName:     "compass_strategy_chance_property_product_stats_di",Columns:       columns,SqlKey:        "compass_strategy_chance_property_product_stats_di",SearchOptions: []*engine.Option{},DSOrderColumn: "pay_combo_cnt",DSOrderType:   alpha.DESC,DSLimit:       50,}// 创建组件UIComponent := NewUIComponent(ctx,mockDriver,DataTable,datasoure,&DateRangeFilter{DaysType:  constu.DateType_LAST_SEVEN_DAYS,StartDate: 0,EndDate:   1653177600,},&DimFilter{DimCondition: map[string]string{"cate_id": "123","market_name":            "碎花","product_property_value": "长款裙子",},},)// 内存分页PageNo := int64(2)PageSize := int64(5)dflimit := (PageNo - 1) * PageSizedfoffset := PageSizeUIComponent.DFOrderColumn = "pay_combo_cnt"UIComponent.DFOrderType = alpha.DESCUIComponent.DFLimit = &dflimitUIComponent.DFOffset = &dfoffsetUIComponent.NeedRank = trueUIComponent.RankKey = "rank"// UIComponent 唯一 Render() 数据函数result, _ := UIComponent.Render()fmt.Println("size:", len(result))fmt.Println("====================================================================================")b, _ := json.Marshal(result)fmt.Println(string(b))
}

gomock

gomock is a mocking framework for the Go programming language. It
integrates well with Go's built-in testing package, but can be used in other
contexts too.

Installation

Once you have installed Go, install the mockgen tool.

Note: If you have not done so already be sure to add $GOPATH/bin to yourPATH.

To get the latest released version use:

Go version < 1.16

GO111MODULE=on go get github.com/golang/mock/mockgen@v1.6.0

Go 1.16+

go install github.com/golang/mock/mockgen@v1.6.0

If you use mockgen in your CI pipeline, it may be more appropriate to fixate
on a specific mockgen version. You should try to keep the library in sync with
the version of mockgen used to generate your mocks.

Running mockgen

mockgen has two modes of operation: source and reflect.

Source mode

Source mode generates mock interfaces from a source file.
It is enabled by using the -source flag. Other flags that
may be useful in this mode are -imports and -aux_files.

Example:

mockgen -source=foo.go [other options]

Reflect mode

Reflect mode generates mock interfaces by building a program
that uses reflection to understand interfaces. It is enabled
by passing two non-flag arguments: an import path, and a
comma-separated list of symbols.

You can use "." to refer to the current path's package.

Example:

mockgen database/sql/driver Conn,Driver# Convenient for `go:generate`.
mockgen . Conn,Driver

Flags

The mockgen command is used to generate source code for a mock
class given a Go source file containing interfaces to be mocked.
It supports the following flags:

• -source: A file containing interfaces to be mocked.

• -destination: A file to which to write the resulting source code. If you
  don't set this, the code is printed to standard output.

• -package: The package to use for the resulting mock class
  source code. If you don't set this, the package name is mock_ concatenated
  with the package of the input file.

• -imports: A list of explicit imports that should be used in the resulting
  source code, specified as a comma-separated list of elements of the formfoo=bar/baz, where bar/baz is the package being imported and foo is
  the identifier to use for the package in the generated source code.

• -aux_files: A list of additional files that should be consulted to
  resolve e.g. embedded interfaces defined in a different file. This is
  specified as a comma-separated list of elements of the formfoo=bar/baz.go, where bar/baz.go is the source file and foo is the
  package name of that file used by the -source file.

• -build_flags: (reflect mode only) Flags passed verbatim to go build.

• -mock_names: A list of custom names for generated mocks. This is specified
  as a comma-separated list of elements of the formRepository=MockSensorRepository,Endpoint=MockSensorEndpoint, whereRepository is the interface name and MockSensorRepository is the desired
  mock name (mock factory method and mock recorder will be named after the mock).
  If one of the interfaces has no custom name specified, then default naming
  convention will be used.

• -self_package: The full package import path for the generated code. The
  purpose of this flag is to prevent import cycles in the generated code by
  trying to include its own package. This can happen if the mock's package is
  set to one of its inputs (usually the main one) and the output is stdio so
  mockgen cannot detect the final output package. Setting this flag will then
  tell mockgen which import to exclude.

• -copyright_file: Copyright file used to add copyright header to the resulting source code.

• -debug_parser: Print out parser results only.

• -exec_only: (reflect mode) If set, execute this reflection program.

• -prog_only: (reflect mode) Only generate the reflection program; write it to stdout and exit.

• -write_package_comment: Writes package documentation comment (godoc) if true. (default true)

For an example of the use of mockgen, see the sample/ directory. In simple
cases, you will need only the -source flag.

Building Mocks

type Foo interface {Bar(x int) int
}func SUT(f Foo) {// ...
}

func TestFoo(t *testing.T) {ctrl := gomock.NewController(t)// Assert that Bar() is invoked.defer ctrl.Finish()m := NewMockFoo(ctrl)// Asserts that the first and only call to Bar() is passed 99.// Anything else will fail.m.EXPECT().Bar(gomock.Eq(99)).Return(101)SUT(m)
}

If you are using a Go version of 1.14+, a mockgen version of 1.5.0+, and are
passing a *testing.T into gomock.NewController(t) you no longer need to callctrl.Finish() explicitly. It will be called for you automatically from a self
registered Cleanup function.

Building Stubs

type Foo interface {Bar(x int) int
}func SUT(f Foo) {// ...
}

func TestFoo(t *testing.T) {ctrl := gomock.NewController(t)defer ctrl.Finish()m := NewMockFoo(ctrl)// Does not make any assertions. Executes the anonymous functions and returns// its result when Bar is invoked with 99.m.EXPECT().Bar(gomock.Eq(99)).DoAndReturn(func(_ int) int {time.Sleep(1*time.Second)return 101}).AnyTimes()// Does not make any assertions. Returns 103 when Bar is invoked with 101.m.EXPECT().Bar(gomock.Eq(101)).Return(103).AnyTimes()SUT(m)
}

Modifying Failure Messages

When a matcher reports a failure, it prints the received (Got) vs the
expected (Want) value.

Got: [3]
Want: is equal to 2
Expected call at user_test.go:33 doesn't match the argument at index 1.
Got: [0 1 1 2 3]
Want: is equal to 1

Modifying Want

The Want value comes from the matcher's String() method. If the matcher's
default output doesn't meet your needs, then it can be modified as follows:

gomock.WantFormatter(gomock.StringerFunc(func() string { return "is equal to fifteen" }),gomock.Eq(15),
)

This modifies the gomock.Eq(15) matcher's output for Want: from is equal to 15 to is equal to fifteen.

Modifying Got

The Got value comes from the object's String() method if it is available.
In some cases the output of an object is difficult to read (e.g., []byte) and
it would be helpful for the test to print it differently. The following
modifies how the Got value is formatted:

gomock.GotFormatterAdapter(gomock.GotFormatterFunc(func(i interface{}) string {// Leading 0sreturn fmt.Sprintf("%02d", i)}),gomock.Eq(15),
)

If the received value is 3, then it will be printed as 03.

Debugging Errors

reflect vendoring error

cannot find package "."
... github.com/golang/mock/mockgen/model

If you come across this error while using reflect mode and vendoring
dependencies there are three workarounds you can choose from:

1. Use source mode.
2. Include an empty import import _ "github.com/golang/mock/mockgen/model".
3. Add --build_flags=--mod=mod to your mockgen command.

This error is due to changes in default behavior of the go command in more
recent versions. More details can be found in#494.