Integration Testing with Github Actions

Integration testing is another layer of testing after unit testing. It groups multiple modules together and applies functional tests to those groups. In the scope of a backend service, it could be testing your module against a database or an external service. In this post, we'll go through setting integration testing with Go, PostgreSQL, Flyway, Github Actions.

Let's start with this sample Go app. It includes Test_LoadDataFromDB to test the function LoadDataFromDB which has interactions with a PostgreSQL database. And looking at goapp_integration_test.go, you may notice these go:build lines:

//go:build integration
// +build integration

They are added so these tests will only run with a specific build tag:

go test -tags=integration

It'll help to separate integration tests from unit tests so you'll only run them for specific occasions.

The next step is to create a PostgreSQL service in our CI via service containers by adding these lines:

services:
  postgres:
    image: postgres:13
    env:
      # Provide the password for postgres
      POSTGRES_PASSWORD: postgres
    ports:
      - 5432:5432
    # Set health checks to wait until postgres has started
    options: >-
      --health-cmd pg_isready
      --health-interval 10s
      --health-timeout 5s
      --health-retries 5

If you need to set up the database before your integration tests, you could use flyway to run the migration script. And luckily, there is a Github action for that:

- uses: joshuaavalon/flyway-action@v1
  with:
    url: jdbc:postgresql://postgres:5432/postgres
    user: postgres
    password: postgres
    locations: filesystem:./migration/sql

In the above config, ./migration/sql is the path to migration SQL scripts.

Finally, you can just add the go test command to run integration tests. It will also run unit tests so no need to have a separate step for that:

- name: Run Tests
  run: |
    go test -v ./... -tags=integration

The work could be found in this repository. Although this is just a simplified version, you can just add more docker containers into your CI if your system is more complicated.