Once your rule is written, you can test it against a variety of artifacts. It could be strings (ANSI/UNICODE), buffers (Hex strings), files or even hashes (with MRF module).
YaraEditor works with “Tests sets”, which are a group of unit tests. Before creating tests, you first need to create a tests set linked to one Rule. Then, inside the tests set, you can create as many unit tests as needed for that rule.
Tests are accessible from either the Rule itself, or from the Tests page. If you are creating a test set from the tests page you will have to specify the rule manually (field with autocomplete).
Note: If you create tests for a rule, the validation won’t pass if some of the tests are failing.