Unit-testing in Dart is still very much under development. We (the Dart authors) currently use a python script (tools/test.py) to execute all our tests. The script runs through predefined directories, looks for files ending with 'Test', executes them, and compares them to the expected outcome.
Several days ago, a first version of test.dart (the equivalent in Dart) has been submitted. In the near future we will switch from tools/test.py to tools/test.dart to execute all our tests.
If you are writing a big project you could reuse our testing-framework. We are using it on a daily basis and it is pretty stable. For smaller projects the time spent on learning the framework might not be worth the effort. I would furthermore not be surprised if there are (or will be) other testing-frameworks.
The ListTest from your question has been written very early, when top-level functions were not yet available. It has since been modified (adding the main function) but we wouldn't write the test in this way anymore. Unless needed, we don't create classes in our test-cases. See, for example, here for a more recent test.
Edit: There is also a unit-test framework in client/testing/unittest/. See here for a test using this framework. This one also has the advantage that it runs in the browser.
Use the test Dart package https://pub.dartlang.org/packages/test
This package was previously named unittest which is now deprecated, but you might come across old articles about it. New tests should be written for the "test" package.
The tests can be run manually (like any other Dart program), or using by pub (which can run individual tests or multiple tests found under a directory).
This post was edited by Viaan Prakash at August 20, 2021 12:38 PM ISTAs part of our ongoing series of blogs on how to write unit tests for Java, this blog is about writing better assertions. Most unit tests are organized in 3 sections:
- Arrange: set up the environment and prepare a bunch of objects to run the unit under test
- Act: call the unit under test
- Assert: check that outputs and side effects of the unit under test are as expected
These three sections are often referred to as the ‘arrange’, ‘act’, and ‘assert’ phases of a test. Other names include ‘given/when/then’ or even ‘setup/exercise/verify’. The first two sections exercise the code on some relevant scenario. The assert section ensures that the code behaves as expected.
Assertions replace us humans in checking that the software does what it should. They express requirements that the unit under test is expected to meet.
Now, often one can write slightly different assertions to capture a given requirement. But, as many of us have noticed, those small differences can have a big impact on how robust, maintainable, or effective a test is. Checking for the right conditions in test assertions is important to produce valuable tests.
