# 4. Annotator Test

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

> **TL;DR**
> Tested Functionality: [7. Annotator](annotator.html)

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

## Define Input Test Data

The `DefaultTestData.simple` file is reused for this test.

Create an input test file `AnnotatorTestData.java` in the `testData` directory. This file contains two instances of Simple Language embedded in the Java code. The first instance is a valid use of the `simple:` prefix followed by the Simple Language key `website`. The second is a valid prefix but an invalid key `websit`, as noted by the test `<error>` [highlighting](testing-highlighting.html).

```JAVA
public class Test {
  public static void main(String[] args) {
    System.out.println("simple:website");
    System.out.println("simple:<error descr="Unresolved property">websit</error>");
  }
}
```

> **Tip:**
> See how to [generate highlighting test data](testing-highlighting.html#generating-test-data).

## Define a Test Method

Add the `testAnnotator()` method to the `SimpleCodeInsightTest` class [previously defined](completion-test.html#define-a-test). Again, this method configures the test fixture by using the test files. It then calls the `checkHighlighting()` method to verify weak warnings.

```JAVA
public void testAnnotator() {
  myFixture.configureByFiles("AnnotatorTestData.java", "DefaultTestData.simple");
  myFixture.checkHighlighting(false, false, false, true);
}
```

## 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.