Go单元测试常见写法

sql.go

package sql_test

import "gorm.io/gorm"

// code
type User struct {
	ID   int
	Name string
}

func findByID(db *gorm.DB, userId int) (u User, exists bool, err error) {
	err = db.Where(`id = ?`, userId).First(&u).Error
	if gorm.ErrRecordNotFound == err {
		return u, false, nil
	}
	if err != nil {
		return u, false, err
	}
	return u, true, nil
}

sql_test.go

package sql_test

import (
	"github.com/DATA-DOG/go-sqlmock"
	"github.com/smartystreets/goconvey/convey"
	"github.com/stretchr/testify/assert"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"testing"
)

func Test_findByID(t *testing.T) {
	db, mock, err := sqlmock.New()
	assert.Nil(t, err)
	assert.NotNil(t, db)

	gormDB, err := gorm.Open(mysql.New(mysql.Config{Conn: db, SkipInitializeWithVersion: true}), &gorm.Config{})
	assert.Nil(t, err)
	assert.NotNil(t, gormDB)

	convey.Convey("Err", t, func() {
		mock.ExpectQuery("(?i)SELECT.*").WithArgs(1).WillReturnError(gorm.ErrInvalidDB)

		_, _, err := findByID(gormDB, 1)

		assert.NotNil(t, err)
		assert.EqualValues(t, err, gorm.ErrInvalidDB)
	})

	convey.Convey("not exists", t, func() {
		mock.ExpectQuery("(?i)SELECT.*").WithArgs(2).WillReturnError(gorm.ErrRecordNotFound)

		user, exists, err := findByID(gormDB, 2)

		assert.Nil(t, err)
		assert.False(t, exists)
		assert.EqualValues(t, user.ID, 0)
		assert.EqualValues(t, user.Name, ``)
	})

	convey.Convey("Err", t, func() {
		mock.ExpectQuery("(?i)SELECT.*").WithArgs(3).WillReturnRows(sqlmock.NewRows(
			[]string{`id`, `name`}).AddRow(3, `teemo`))

		user, exists, err := findByID(gormDB, 3)

		assert.Nil(t, err)
		assert.True(t, exists)
		assert.EqualValues(t, user.ID, 3)
		assert.EqualValues(t, user.Name, `teemo`)
	})
}