intellij-sdk-code-samples/tutorials/writing_tests_for_plugins/completion_test.md

title
3. Completion Test

This test checks if code completion, implemented in the Reference Contributor section of the Custom Language Support Tutorial, works as expected.

3.1. Define Test Data

Create an input Simple file DefaultTestData.simple for the test.

{% include /code_samples/simple_language_plugin/src/test/testData/DefaultTestData.simple %}

Create an input java file CompleteTestData.java for the test.

{% include /code_samples/simple_language_plugin/src/test/testData/CompleteTestData.java %}

3.2. Define a Test

Subclass LightJavaCodeInsightFixtureTestCase to create SimpleCodeInsightTest. Override getTestDataPath(), and return the path from the root of this plugin module to the testData directory. At this point only one test is defined, testCompletion().

public class SimpleCodeInsightTest extends LightJavaCodeInsightFixtureTestCase {
  @Override
  protected String getTestDataPath() {
    return "src/test/testData";
  }

  public void testCompletion() {
    myFixture.configureByFiles("CompleteTestData.java", "DefaultTestData.simple");
    myFixture.complete(CompletionType.BASIC, 1);
    List<String> strings = myFixture.getLookupElementStrings();
    assertTrue(strings.containsAll(Arrays.asList("key with spaces", "language", "message", "tab", "website")));
    assertEquals(5, strings.size());
  }
}

3.3. Run the test

As before, run the test and make sure it's green.