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

title
3. Completion Test

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

3.1. Define Test Data

Create the DefaultTestData.simple properties file in the testData directory.

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

Create a test input Java file CompleteTestData.java in the testData directory. This file contains a Simple Language snippet within the Java.

{% 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 in SimpleCodeInsightTest: testCompletion(). This method:

• Configures the test using the two input files.
• Calls the basic completion functionality. Behind the scenes, this method call creates a list of possible elements to complete the embedded Simple Language reference.
• Checks the list of possible element names to ensure it contains all Simple Language completion possibilities.

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

Run the test by:

• Opening the Gradle Tool Window.
• Drill down to the simple_language_plugin. You may need to reimport it as a Gradle project.
• Drill down under simple_language_plugin to Tasks, verification, test task.
• Run the test task.

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