Problem with using JUnit4to5Migration

[timtebeek]

Discussed in openrewrite/rewrite#3911

^{Originally posted by ErhardSiegl January 13, 2024}
I'm rather new to OpenRewrite. I tried to migrate a project from Junit4 to Junit5 with org.openrewrite.java.testing.junit5.JUnit4to5Migration. The Java files worked fine, but the the Jupiter dependencies were not added to the pom.xml. When I changed the recipe in the following way it worked:

3c3
< name: org.openrewrite.java.testing.junit5.JUnit4to5Migration
---
> name: org.openrewrite.java.testing.junit5.JUnit4to5Migration1
68c68
<       onlyIfUsing: org.junit.jupiter.api.Test
---
>       onlyIfUsing: org.junit.Test
70a71,79
>       groupId: org.mockito
>       artifactId: mockito-junit-jupiter
>       version: 5.x
>       onlyIfUsing: org.mockito.runners.MockitoJUnitRunner
>       acceptTransitive: true
>   - org.openrewrite.java.dependencies.RemoveDependency:
>       groupId: org.mockito
>       artifactId: mockito-all
>   - org.openrewrite.java.dependencies.AddDependency:

It seems that the onlyIfUsing needs the original class (org.junit.Test) and not the classname which is created by the recipe (org.junit.jupiter.api.Test). Is this a bug in the recipe or did I miss anything? I use the following configuration:

            <plugin>
                <groupId>org.openrewrite.maven</groupId>
                <artifactId>rewrite-maven-plugin</artifactId>
                <version>5.17.1</version>
                <dependencies>
                    <dependency>
                        <groupId>org.openrewrite.recipe</groupId>
                        <artifactId>rewrite-migrate-java</artifactId>
                        <version>2.5.0</version>
                    </dependency>
                    <dependency>
                        <groupId>org.openrewrite.recipe</groupId>
                        <artifactId>rewrite-testing-frameworks</artifactId>
                        <version>2.1.5</version>
                    </dependency>
                </dependencies>
            </plugin>

and start it with mvn rewrite:run -Drewrite.activeRecipes=org.openrewrite.java.testing.junit5.JUnit4to5Migration1
rewrite.yml.txt

[timtebeek]

Hi @ErhardSiegl ; From the above it seems we might want to change the UseMockitoExtension recipe as defined here

rewrite-testing-frameworks/src/main/resources/META-INF/rewrite/junit5.yml

Lines 180 to 197 in 430f635

	type: specs.openrewrite.org/v1beta/recipe
	name: org.openrewrite.java.testing.junit5.UseMockitoExtension
	displayName: Use Mockito JUnit Jupiter extension
	description: Migrate uses of `@RunWith(MockitoJUnitRunner.class)` (and similar annotations) to `@ExtendWith(MockitoExtension.class)`.
	tags:
	- testing
	- junit
	- mockito
	recipeList:
	- org.openrewrite.java.testing.mockito.Mockito1to4Migration
	- org.openrewrite.java.testing.mockito.MockitoJUnitRunnerSilentToExtension
	- org.openrewrite.java.testing.junit5.RunnerToExtension:
	runners:
	- org.mockito.runners.MockitoJUnitRunner
	- org.mockito.junit.MockitoJUnitRunner
	- org.mockito.runners.MockitoJUnit44Runner
	- org.mockito.junit.MockitoJUnit44Runner
	extension: org.mockito.junit.jupiter.MockitoExtension

Or maybe even better: add the above to mockito.yml such that it's included as part of UseMockitoExtension. Would you want to get credit for that change by opening a pull request here?

[ErhardSiegl]

Hi @timtebeek,
I'd rather not do the pull request since I'm unsure about the consequences and how to test the changes apart from my code.
I still don't understand the onlyIfUsing: org.junit.jupiter.api.Test. According to the examples in mockito.yml and junit5.yml this seems to be correct. However I had to change it to onlyIfUsing: org.junit.Test to make it work.
The

>   - org.openrewrite.java.dependencies.RemoveDependency:
>       groupId: org.mockito
>       artifactId: mockito-all

is apparently not included in the recipes. But maybe mockito-all was not the best choice in the first place. My code is a couple of years old.

[timtebeek]

Hi @ErhardSiegl ; not problem at all; I've applied part of your suggested changes in 216983b just now.

The onlyIfUsing looks at the lossless semantic tree type elements to see if the argument class is used in the current tree before adding a dependency. That conditionality allows recipes to always run, but only make changes when those types are used. It is sensitive to recipe ordering, and I suspect you had trouble coming from Mockito 1.x here, as evidenced by the use of mockito-all.

To answer your question about how recipe changes are tested, you can have a look at this example test that's part of the Mockito and JUnit Jupiter migration.

rewrite-testing-frameworks/src/test/java/org/openrewrite/java/testing/junit5/RunnerToExtensionTest.java

Lines 29 to 68 in 53cfd4c

	class RunnerToExtensionTest implements RewriteTest {
	@Override
	public void defaults(RecipeSpec spec) {
	spec
	.parser(JavaParser.fromJavaVersion()
	.classpathFromResources(new InMemoryExecutionContext(), "junit-4.13", "mockito-all-1.10"))
	.recipe(new RunnerToExtension(
	List.of("org.mockito.runners.MockitoJUnitRunner"),
	"org.mockito.junit.jupiter.MockitoExtension"
	)
	);
	}
	@DocumentExample
	@Test
	void mockito() {
	rewriteRun(
	//language=java
	java(
	"""
	import org.junit.runner.RunWith;
	import org.mockito.runners.MockitoJUnitRunner;
	@RunWith(MockitoJUnitRunner.class)
	public class MyTest {
	}
	""",
	"""
	import org.junit.jupiter.api.extension.ExtendWith;
	import org.mockito.junit.jupiter.MockitoExtension;
	@ExtendWith(MockitoExtension.class)
	public class MyTest {
	}
	"""
	)
	);
	}
	}

Similar tests can be added if you feel there are cases left uncovered. Thanks for reporting your issue and suggested improvements!