Category Archives: Testing

mountebank for mocking and stubbing http services (rest+graphql+grpc)

http://www.mbtest.org/docs/api/stubs can be used to stub http(s)/tcp/smtp protocols. And has community plugins for grpc, graphql, websockets. You can configure it with imposters.ejs like below:

{
  "port": 80,
  "protocol": "http",
  "defaultResponse": {
    "statusCode": 404,
    "headers": {}
  },
  "stubs": [
    <% include stubs/service1.json %>,
    <% include stubs/service2.json %>,
    <% include stubs/service3.json %>
  ]
}

{

"port": 80,

"protocol": "http",

"defaultResponse": {

"statusCode": 404,

"headers": {}

"stubs": [

<% include stubs/service1.json %>,

<% include stubs/service2.json %>,

<% include stubs/service3.json %>

]

}

docker-compose.yml

version: "3.5"

services:
  mountebank:
    container_name: mountebank
    image: jkris/mountebank:latest
    volumes:
      - ./:/mountebank
    ports:
      - "15050:80"
    command: --configfile /mountebank/imposters.ejs --allowInjection

version: "3.5"

services:

mountebank:

container_name: mountebank

image: jkris/mountebank:latest

volumes:

- ./:/mountebank

ports:

- "15050:80"

command: --configfile /mountebank/imposters.ejs --allowInjection

HTTP Toolkit — another alternative to Charles Proxy for http calls interception

https://httptoolkit.com/ It has a free version which does something similar to Charles Proxy, so you can hack into the middle of any request/response according to the rules specified.

Docker and Kubernetes basics for developers

Docker Docker containers are much more lightweight compared to classic VMs as they leverage host OS instead of starting their own OS. Containers are using 2 features of Linux-based OS: Namespaces and Cgroups (Control Groups). Namespace Lets you allocate resources in an isolated environment (like a sandbox). On a container start, docker daemon generates a …

Mock sql (sqlx) db on golang

I am using this library — https://pkg.go.dev/github.com/data-dog/go-sqlmock. That’s how you can use it for mocking db querying:

Fast and simple mock server app by swagger file

I’ve tried Mockoon for mocking by swagger/OpenAPI spec file, and it works pretty good. It autogenerates the response based on swagger format, and you are able to update any response field the way you want, save your changes and run the mock server with one click on the port you specify. It is a separate …

Types of load tests

Load test types explained by k6. Smoke tests Verify that your system can handle minimal load, without any problems. Like 1 rps for 1 minute. Load tests Assess system performance in terms of concurrent users or requests per second. If you want to make sure that you can handle 500 rps, you can gradually increase …

mmock for mocking microservices

It is a very easy to set up though pretty powerful tool with support for delays and handling query params. It also has a console for checking all the requests and corresponding responses matched. Here it is https://github.com/jmartin82/mmock. Below I describe a way to use it with docker-compose for local development.

Mocking for unit-tests and e2e-tests in golang

Some patterns to test your golang app. Mocking an interface

	mockS3 := &mocks.S3API{}

	mockResultFn := func(input *s3.ListObjectsInput) *s3.ListObjectsOutput {
		output := &s3.ListObjectsOutput{}
		output.SetCommonPrefixes([]*s3.CommonPrefix{
			&s3.CommonPrefix{
				Prefix: aws.String("2017-01-01"),
			},
		})
		return output
	}

	// NB: .Return(...) must return the same signature as the method being mocked.
	//     In this case it's (*s3.ListObjectsOutput, error).
	mockS3.On("ListObjects", mock.MatchedBy(func(input *s3.ListObjectsInput) bool {
		return input.Delimiter != nil && *input.Delimiter == "/" && input.Prefix == nil
	})).Return(mockResultFn, nil)

	listingInput := &s3.ListObjectsInput{
		Bucket:    aws.String("foo"),
		Delimiter: aws.String("/"),
	}
	listingOutput, err := mockS3.ListObjects(listingInput)
	if err != nil {
		panic(err)
	}

	for _, x := range listingOutput.CommonPrefixes {
		fmt.Printf("common prefix: %+v\n", *x)
	}

mockS3 := &mocks.S3API{}

mockResultFn := func(input *s3.ListObjectsInput) *s3.ListObjectsOutput {

output := &s3.ListObjectsOutput{}

output.SetCommonPrefixes([]*s3.CommonPrefix{

&s3.CommonPrefix{

Prefix: aws.String("2017-01-01"),

})

return output

}

// NB: .Return(...) must return the same signature as the method being mocked.

// In this case it's (*s3.ListObjectsOutput, error).

mockS3.On("ListObjects", mock.MatchedBy(func(input *s3.ListObjectsInput) bool {

return input.Delimiter != nil && *input.Delimiter == "/" && input.Prefix == nil

})).Return(mockResultFn, nil)

listingInput := &s3.ListObjectsInput{

Bucket: aws.String("foo"),

Delimiter: aws.String("/"),

}

listingOutput, err := mockS3.ListObjects(listingInput)

if err != nil {

panic(err)

}

for _, x := range listingOutput.CommonPrefixes {

fmt.Printf("common prefix: %+v\n", *x)

}

https://github.com/vektra/mockery Mocking SQL database

// a successful case
func TestShouldUpdateStats(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
	}
	defer db.Close()

	mock.ExpectBegin()
	mock.ExpectExec("UPDATE products").WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO product_viewers").WithArgs(2, 3).WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectCommit()

	// now we execute our method
	if err = recordStats(db, 2, 3); err != nil {
		t.Errorf("error was not expected while updating stats: %s", err)
	}

	// we make sure that all expectations were met
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("there were unfulfilled expectations: %s", err)
	}
}

// a successful case

func TestShouldUpdateStats(t *testing.T) {

db, mock, err := sqlmock.New()

if err != nil {

t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)

}

defer db.Close()

mock.ExpectBegin()

mock.ExpectExec("UPDATE products").WillReturnResult(sqlmock.NewResult(1, 1))

mock.ExpectExec("INSERT INTO product_viewers").WithArgs(2, 3).WillReturnResult(sqlmock.NewResult(1, 1))

mock.ExpectCommit()

// now we execute our method

if err = recordStats(db, 2, 3); err != nil {

t.Errorf("error was not expected while updating stats: %s", err)

}

// we make sure that all expectations were met

if err := mock.ExpectationsWereMet(); err != nil {

t.Errorf("there were unfulfilled expectations: %s", err)

}

https://github.com/DATA-DOG/go-sqlmock Mocking HTTP server for unit-tests

	handler := func(w http.ResponseWriter, r *http.Request) {
		io.WriteString(w, "<html><body>Hello World!</body></html>")
	}

	req := httptest.NewRequest("GET", "http://example.com/foo", nil)
	w := httptest.NewRecorder()
	handler(w, req)

	resp := w.Result()
	body, _ := ioutil.ReadAll(resp.Body)

	fmt.Println(resp.StatusCode)
	fmt.Println(resp.Header.Get("Content-Type"))
	fmt.Println(string(body))

handler := func(w http.ResponseWriter, r *http.Request) {

io.WriteString(w, "<html><body>Hello World!</body></html>")

}

req := httptest.NewRequest("GET", "http://example.com/foo", nil)

w := httptest.NewRecorder()

handler(w, req)

resp := w.Result()

body, _ := ioutil.ReadAll(resp.Body)

fmt.Println(resp.StatusCode)

fmt.Println(resp.Header.Get("Content-Type"))

fmt.Println(string(body))

https://golang.org/pkg/net/http/httptest/ Stubbing HTTP server for e2e-tests

{
	"host": "example.com",
	"method": "GET|POST|PUT|PATCH|... (Mandatory)", 
	"path": "/your/path/:variable (Mandatory)",
	"queryStringParameters": {
		"name": ["value"],
		"name": ["value", "value"]
	},
	"headers": {
		"name": ["value"]
	},
	"cookies": {
		"name": "value"
	},
	"body": "Expected Body"
}

{

"host": "example.com",

"method": "GET|POST|PUT|PATCH|... (Mandatory)",

"path": "/your/path/:variable (Mandatory)",

"queryStringParameters": {

"name": ["value"],

"name": ["value", "value"]

"headers": {

"name": ["value"]

"cookies": {

"name": "value"

"body": "Expected Body"

}

https://github.com/jmartin82/mmock Mocking for e2e-tests with dockertest

var db *sql.DB

func TestMain(m *testing.M) {
	// uses a sensible default on windows (tcp/http) and linux/osx (socket)
	pool, err := dockertest.NewPool("")
	if err != nil {
		log.Fatalf("Could not connect to docker: %s", err)
	}

	// pulls an image, creates a container based on it and runs it
	resource, err := pool.Run("mysql", "5.7", []string{"MYSQL_ROOT_PASSWORD=secret"})
	if err != nil {
		log.Fatalf("Could not start resource: %s", err)
	}

	// exponential backoff-retry, because the application in the container might not be ready to accept connections yet
	if err := pool.Retry(func() error {
		var err error
		db, err = sql.Open("mysql", fmt.Sprintf("root:secret@(localhost:%s)/mysql", resource.GetPort("3306/tcp")))
		if err != nil {
			return err
		}
		return db.Ping()
	}); err != nil {
		log.Fatalf("Could not connect to docker: %s", err)
	}

	code := m.Run()
	
	// You can't defer this because os.Exit doesn't care for defer
	if err := pool.Purge(resource); err != nil {
		log.Fatalf("Could not purge resource: %s", err)
	}
	
	os.Exit(code)
}

func TestSomething(t *testing.T) {
	// db.Query()
}

var db *sql.DB

func TestMain(m *testing.M) {

// uses a sensible default on windows (tcp/http) and linux/osx (socket)

pool, err := dockertest.NewPool("")

if err != nil {

log.Fatalf("Could not connect to docker: %s", err)

}

// pulls an image, creates a container based on it and runs it

resource, err := pool.Run("mysql", "5.7", []string{"MYSQL_ROOT_PASSWORD=secret"})

if err != nil {

log.Fatalf("Could not start resource: %s", err)

}

// exponential backoff-retry, because the application in the container might not be ready to accept connections yet

if err := pool.Retry(func() error {

var err error

db, err = sql.Open("mysql", fmt.Sprintf("root:secret@(localhost:%s)/mysql", resource.GetPort("3306/tcp")))

if err != nil {

return err

}

return db.Ping()

}); err != nil {

log.Fatalf("Could not connect to docker: %s", err)

}

code := m.Run()

// You can't defer this because os.Exit doesn't care for defer

if err := pool.Purge(resource); err != nil {

log.Fatalf("Could not purge resource: %s", err)

}

os.Exit(code)

}

func TestSomething(t *testing.T) {

// db.Query()

}

https://github.com/ory/dockertest

Integration tests with testcontainers-go

Here is the go library that simplifies integration tests with docker containers — https://github.com/testcontainers/testcontainers-go. That’s how you can use it to test sql — https://github.com/testcontainers/testcontainers-go/blob/master/docs/examples/cockroachdb.md. Project documentation — https://golang.testcontainers.org/features/docker_compose/ The idea is to prepare the environment, build your app, then make requests and check the DB state.

Test Push Notifications

https://github.com/onmyway133/PushNotifications