# 9. Commenter Test

> For the complete documentation index, see [llms.txt](https://plugins.jetbrains.com/docs/intellij/llms.txt).

> **TL;DR**
> Tested Functionality: [18. Commenter](commenter.html)

> **Tip:**
> This page is part of multistep [Testing a Custom Language Plugin](writing-tests-for-plugins.html) tutorial.

## Define a Test Method

Add the `testCommenter()` method to the `SimpleCodeInsightTest` class [previously defined](completion-test.html#define-a-test). This test constructs a Simple Language properties file containing one line, with the virtual caret positioned at the beginning of the line. The test calls the commenter to insert a comment character at the caret, then verifies the results. It again calls the line comment action to remove the comment character and verifies the results.

```JAVA
public void testCommenter() {
  myFixture.configureByText(SimpleFileType.INSTANCE, "<caret>website = https://en.wikipedia.org/");
  CommentByLineCommentAction commentAction = new CommentByLineCommentAction();
  commentAction.actionPerformedImpl(getProject(), myFixture.getEditor());
  myFixture.checkResult("#website = https://en.wikipedia.org/");
  commentAction.actionPerformedImpl(getProject(), myFixture.getEditor());
  myFixture.checkResult("website = https://en.wikipedia.org/");
}
```

## Run the Test

Run the test and make sure it's successful.

Procedure: Running tests

1. Open the Gradle Tool Window.

2. Select the simple_language_plugin node. You may need to reimport it as a Gradle project.

3. Drill down under simple_language_plugin to Tasks, verification, test task.

4. Run the test task.

The results are displayed in the Run Tool Window, and also written to the `simple_language_plugin/build/test-results/test` directory.

If the Run Tool Window displays the error Test events were not received, do the following:

1. In the Gradle Tool Window, drill down under simple_language_plugin to Tasks, build, clean task.

2. Run the clean task, which deletes the `simple_language_plugin/build` directory.

3. Restart the test.