JarCastingannotation-processor-testing
An easy way to verify that your annotation processor is emitting the right diagnostics.
Setup
In order to use any of the test runners, you must include your test sources as a resource:
<build>
...
<testResources>
<testResource>
<directory>src/test/java/</directory>
</testResource>
<testResource>
<directory>src/test/resources/</directory>
</testResource>
</testResources>
...
</build>
Additionally, you may need to disable annotation processing during test compilation if you are testing ERROR diagnostics.
<build>
...
<plugins>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<executions>
<execution>
<id>default-testCompile</id>
<goals>
<goal>testCompile</goal>
</goals>
<configuration>
<proc>none</proc>
</configuration>
</execution>
</executions>
</plugins
...
</build>
Usage
Annotate your test class with @UseProcessor, @ExpectError, and @ExpectDiagnostic:
@UseProcessor(YourProcessor.class)
public class YourProcessorTest {
@ExpectError @IncorrectlyUsedAnnotation
public void method() {}
@ExpectError("substring of the message") @IncorrectlyUsedAnnotation
public void method1() {}
@ExpectError(lineOffset = 1) // Expect a diagnostic on the next line.
@IncorrectlyUsedAnnotation
public void method2() {}
@ExpectError(value = "[abc]+", regex = true) @IncorrectlyUsedAnnotation
public void method3() {}
@ExpectError(testName = "descriptive JUnit test name") @IncorrectlyUsedAnnotation
public void method4() {}
// No @Expect annotation needed.
@CorrectlyUsedAnnotation
public void method5() {}
}
JUnit 4
Add @RunWith(DiagnosticTester.class) to your test class.
JUnit 5
Ensure that annotation-processor-testing-junit5 is included as a dependency, and the JUnit 5 launcher should automatically discover your tests.