github.com/stretchr/testify v1.8.4: mock.Mock

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:golang/github.com/stretchr/testify@v1.8.4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/stretchr/testify@v1.8.4
Demonstrate these symbols/APIs:
  - mock.Mock

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:76207756e46a85c0702df4171aa78a75e4d215bea5c1e62940c3a0942d9edbf7","contract":["mock.Mock.On registers expected method calls with argument values, and mock.Mock.Called retrieves matching return values","mock.Mock.AssertExpectations returns true when all registered expectations have been fulfilled","mock.Mock.AssertExpectations returns false and reports error when expected method calls are unfulfilled","mock.Mock.AssertCalled and AssertNotCalled verify whether specific calls occurred with specified arguments","mock.Mock.AssertNumberOfCalls verifies the exact invocation count of a mocked method","mock.Mock supports argument matchers including mock.Anything and mock.AnythingOfType for parameter matching"],"goal":"verify pkg:golang/github.com/stretchr/testify@v1.8.4","kind":"HOW","packages":["pkg:golang/github.com/stretchr/testify@v1.8.4"],"schemaVersion":1,"symbols":["mock.Mock"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/stretchr/testify@v1.8.4"],"schemaVersion":1,"subject":"pkg:golang/github.com/stretchr/testify@v1.8.4","symbols":["mock.Mock"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.20

require github.com/stretchr/testify v1.8.4

require (
	github.com/davecgh/go-spew v1.1.1 // indirect
	github.com/pmezard/go-difflib v1.0.0 // indirect
	github.com/stretchr/objx v0.5.0 // indirect
	gopkg.in/yaml.v3 v3.0.1 // indirect
)

github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"errors"
	"fmt"

	"github.com/stretchr/testify/mock"
)

type dummyTestingT struct {
	failed bool
	errors []string
}

func (d *dummyTestingT) Logf(format string, args ...interface{}) {}

func (d *dummyTestingT) Errorf(format string, args ...interface{}) {
	d.failed = true
	d.errors = append(d.errors, fmt.Sprintf(format, args...))
}

func (d *dummyTestingT) FailNow() {
	d.failed = true
}

type UserRepository struct {
	mock.Mock
}

func (m *UserRepository) FindByID(id int) (string, error) {
	args := m.Called(id)
	return args.String(0), args.Error(1)
}

func (m *UserRepository) Save(id int, name string) error {
	args := m.Called(id, name)
	return args.Error(0)
}

func main() {
	repo := new(UserRepository)

	// Set expectations
	repo.On("FindByID", 1).Return("entity-1", nil)
	repo.On("FindByID", 2).Return("", errors.New("record not found"))
	repo.On("Save", mock.AnythingOfType("int"), mock.AnythingOfType("string")).Return(nil)

	// Call methods
	res1, err1 := repo.FindByID(1)
	fmt.Printf("find 1: %s, err: %v\n", res1, err1)

	res2, err2 := repo.FindByID(2)
	fmt.Printf("find 2: %s, err: %v\n", res2, err2)

	err3 := repo.Save(1, "record-data")
	fmt.Printf("save: %v\n", err3)

	t := &dummyTestingT{}
	assertOk := repo.AssertExpectations(t)
	calledOk := repo.AssertCalled(t, "FindByID", 1)
	notCalledOk := repo.AssertNotCalled(t, "FindByID", 99)
	numOk := repo.AssertNumberOfCalls(t, "FindByID", 2)

	fmt.Printf("assertions: expectations=%v called=%v notCalled=%v numCalls=%v\n",
		assertOk, calledOk, notCalledOk, numOk)
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/github.com/stretchr/testify@v1.8.4",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/stretchr/testify@v1.8.4"
  ],
  "symbols": [
    "mock.Mock"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/stretchr/testify/mock"
)

type dummyTestingT struct {
	failed bool
	errors []string
}

func (t *dummyTestingT) Logf(format string, args ...interface{}) {}

func (t *dummyTestingT) Errorf(format string, args ...interface{}) {
	t.failed = true
	t.errors = append(t.errors, fmt.Sprintf(format, args...))
}

func (t *dummyTestingT) FailNow() {
	t.failed = true
}

type GreeterMock struct {
	mock.Mock
}

func (m *GreeterMock) Greet(name string) (string, error) {
	args := m.Called(name)
	return args.String(0), args.Error(1)
}

type CalculatorMock struct {
	mock.Mock
}

func (c *CalculatorMock) Compute(op string, val int) int {
	args := c.Called(op, val)
	return args.Int(0)
}

func main() {
	// Assertion 1: mock.Mock.On registers expected method calls with argument values, and mock.Mock.Called retrieves matching return values
	{
		m := new(GreeterMock)
		m.On("Greet", "world").Return("hello world", nil)

		res, err := m.Greet("world")
		if res != "hello world" || err != nil {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected 'hello world' and nil error, got %q, %v\n", res, err)
			os.Exit(1)
		}
	}

	// Assertion 2: mock.Mock.AssertExpectations returns true when all registered expectations have been fulfilled
	{
		m := new(GreeterMock)
		m.On("Greet", "first").Return("hello first", nil)
		_, _ = m.Greet("first")

		t := &dummyTestingT{}
		ok := m.AssertExpectations(t)
		if !ok || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: AssertExpectations returned false or recorded errors for fulfilled mock\n")
			os.Exit(1)
		}
	}

	// Assertion 3: mock.Mock.AssertExpectations returns false and reports error when expected method calls are unfulfilled
	{
		m := new(GreeterMock)
		m.On("Greet", "uncalled").Return("hello", nil)

		t := &dummyTestingT{}
		ok := m.AssertExpectations(t)
		if ok || !t.failed || len(t.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: AssertExpectations should return false and record error for unfulfilled mock\n")
			os.Exit(1)
		}
	}

	// Assertion 4: mock.Mock.AssertCalled and AssertNotCalled verify whether specific calls occurred with specified arguments
	{
		m := new(GreeterMock)
		m.On("Greet", "target").Return("hello target", nil)
		_, _ = m.Greet("target")

		t := &dummyTestingT{}
		calledOk := m.AssertCalled(t, "Greet", "target")
		notCalledOk := m.AssertNotCalled(t, "Greet", "other")
		if !calledOk || !notCalledOk || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: AssertCalled or AssertNotCalled failed\n")
			os.Exit(1)
		}
	}

	// Assertion 5: mock.Mock.AssertNumberOfCalls verifies the exact invocation count of a mocked method
	{
		m := new(GreeterMock)
		m.On("Greet", "repeat").Return("hi", nil)
		_, _ = m.Greet("repeat")
		_, _ = m.Greet("repeat")

		t := &dummyTestingT{}
		numOk := m.AssertNumberOfCalls(t, "Greet", 2)
		if !numOk || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: AssertNumberOfCalls should succeed for exact count 2\n")
			os.Exit(1)
		}

		tWrong := &dummyTestingT{}
		wrongOk := m.AssertNumberOfCalls(tWrong, "Greet", 1)
		if wrongOk || !tWrong.failed || len(tWrong.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: AssertNumberOfCalls should report error for incorrect count\n")
			os.Exit(1)
		}
	}

	// Assertion 6: mock.Mock supports argument matchers including mock.Anything and mock.AnythingOfType for parameter matching
	{
		calc := new(CalculatorMock)
		calc.On("Compute", mock.Anything, mock.AnythingOfType("int")).Return(100)

		out := calc.Compute("double", 50)
		if out != 100 {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: Compute return value mismatch: got %d, expected 100\n", out)
			os.Exit(1)
		}

		t := &dummyTestingT{}
		ok := calc.AssertExpectations(t)
		if !ok || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: AssertExpectations failed for mock with matchers\n")
			os.Exit(1)
		}
	}

	fmt.Println("All contract assertions passed.")
}