Using TestContainers for Integration Tests
This repository contains strategies for integration testing with TestContainers and XUnit. Specifically, these tests show how to use XUnit's facilities to provide dependencies on several levels:
- Dependency per test
- Dependency per test class
- Dependency per test collection
These three strategies provide varying levels of execution speed and test isolation.
The strategy you choose will be based on your scenarios and preferred outcome.
As a general rule, it's best to start with dependency per test, as it provides the most isolation between tests, but it can be time-intensive as your test suite grows.
The other strategies can be powerful in speeding up your test runs, but require thinking about initialization and clean-up strategies as state can "leak" between tests.
Other Scenarios You Might Be Interested In
I've also included two tests that might be of interest to folks writing integration tests. Pulling an image from the registry (HttpTest), and Building a custom image and running it as a container (CustomContainerTest).
In general, TestContainers are infinitely configurable for your testing needs, but the library requires some work on your part.
Getting Started
You'll need the following to run these tests.
- .NET 8 SDK
- JetBrains Rider (optional)
Running the tests in the JetBrains Rider test runner will show how tests are isolated, as the Container Id is printed to the test runner output window. Also note the time it takes to execute each collection of tests.
On my machine, the tests take about this much time:
- Dependency per test: 3 tests @ 13 seconds.
- Dependency per test class: 3 tests @ 9 seconds
- Dependency per test collection: 6 tests @ 4 seconds
Each strategy is running identical tests.