End-to-end testing checks an application flow against a running stack, rather than testing one component in isolation or the integration of two modules. For an order flow, the stack contains the minimum required services: MySQL, Payment, and Order. A client creates an order, retrieves it, and checks the returned fields. section 7.4 section 7.1
Keep these tests selective. More running components reduce isolation, increase resource use, and make execution slower and more expensive. The testing pyramid therefore places fewer end-to-end tests above larger suites of unit and integration tests; it does not suggest omitting them. section 7.1
To run the order-flow test:
- Create a separate Go e2e module. Put the Docker Compose definition and database setup files in its resources directory; provide Dockerfiles for the services and use mysql:8 for the database. section 7.4.3 section 7.4.1
- Start the Compose stack in SetupSuite through Testcontainers. Connect a gRPC Order client to the running service, create an order, retrieve it, and assert that the returned fields match. Stop the stack in TearDownSuite even when the test fails, so it does not keep consuming resources. section 7.4.7 section 7.4
Create an order through the running stack
Run `go test -run "^TestCreateOrderTestSuite$"` from the e2e module. The test connects to the Order service at `localhost:8080`, calls Create with a user and an order item, checks for a creation error, then gets the order and verifies its fields. The suite shuts down the Compose stack afterward. section 7.4.7
func (c *CreateOrderTestSuite) SetupSuite() {
composeFilePaths := []string{"resources/docker-compose.yml"} #1
identifier := strings.ToLower(uuid.New().String()) #2
compose := testcontainers.NewLocalDockerCompose(composeFilePaths,
identifier)
c.compose = compose #3
execError := compose.
WithCommand([]string{"up", "-d"}).
Invoke() #4
err := execError.Error
if err != nil {
log.Fatalf("Could not run compose stack: %v", err)
}
}
The SetupSuite listing shows Testcontainers invoking `docker-compose up -d` before the gRPC assertions run. section 7.4.7
