international-transfers-service
A sample service with two dependencies (a database and another service) with Batect-based build and testing environments.
Building, testing, running etc.
Run ./batect --list-tasks to see the available commands and their descriptions, then ./batect <task> to run <task>.
All of this is controlled by batect.yml, and it shows a number of common patterns you might adopt in your own application - things like tasks for different kinds of tests, a task to run the application, and a task to start a shell in your build environment.
Tests
There are three kinds of tests:
-
Unit tests (stored under
src/test): exactly what it sounds like. This might also include contract tests. -
Integration tests (stored under
src/integrationTest): tests for individual components (eg. single methods or classes) that interact with an external dependency and that require that dependency (or a fake) to be running for the tests to pass. An example of something to test here is interactions with our database. -
Journey tests (stored under
src/journeyTest): tests that exercise one or more user journeys. Some people might call these functional tests or end-to-end tests. These tests require all external dependencies (or appropriate fakes) to be running for the tests to pass, and interact with the service as a user / consumer would (using its HTTP interface, for example). As these tests only use the external API, these could be written in a different language, but we use Java for everything for simplicity.
Important notes
As this is just a sample application used to demonstrate how to use Batect, the code itself is definitely not production ready. A number of shortcuts have been taken, including:
- There is no error checking or validation
- There is no logging
- Nothing is configurable (eg. port used for HTTP and database connection string are hard-coded)
- The database schema is hardcoded into the database Docker container (ideally some kind of schema migrations system would be in place)
- There are no consumer-driven contract tests in place
- Many of the unit and integration tests are very simple, and many test cases are missing
- Many things could be more efficient or done in a more maintainable way
- No dependency injection framework, everything is done by hand