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JUnit Jupiter migration from JUnit 4.x

Recipe IDorg.openrewrite.java.testing.junit5.JUnit4to5Migration
Artifactorg.openrewrite.recipe:rewrite-testing-frameworks

Migrates JUnit 4.x tests to JUnit Jupiter.

Composite recipeJavajunittestingModerne Source Available License
Try in PlatformTry this recipe in the Moderne platform. Not a user yet? You’ll get a no-setup demo environment, with nothing to install or configure.

Definition​

Preconditions2
Recipes56
56 recipes

Examples​

java
Before
import org.junit.Test;
import org.junit.experimental.runners.Enclosed;
import org.junit.runner.RunWith;

@RunWith(Enclosed.class)
public class RootTest {
    public static class InnerTest {
        @Test
        public void test() {
        }
    }
}
After
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

public class RootTest {
    @Nested
    public class InnerTest {
        @Test
        public void test() {
        }
    }
}
java
Before
import org.junit.Assert;
import org.junit.Test;

import static java.util.Arrays.asList;
import static org.hamcrest.Matchers.containsInAnyOrder;

public class SampleTest {
    @SuppressWarnings("ALL")
    @Test
    public void filterShouldRemoveUnusedConfig() {
        Assert.assertThat(asList("1", "2", "3"),
                containsInAnyOrder("3", "2", "1"));
    }
}
After
import org.junit.jupiter.api.Test;

import static java.util.Arrays.asList;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.containsInAnyOrder;

public class SampleTest {
    @SuppressWarnings("ALL")
    @Test
    public void filterShouldRemoveUnusedConfig() {
        assertThat(asList("1", "2", "3"),
                containsInAnyOrder("3", "2", "1"));
    }
}
java
Before
package org.openrewrite.java.testing.junit5;

import org.junit.Before;
import org.junit.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.util.List;

import static org.mockito.Mockito.verify;

public class MockitoTests {
    @Mock
    List<String> mockedList;

    @Before
    public void initMocks() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void usingAnnotationBasedMock() {

        mockedList.add("one");
        mockedList.clear();

        verify(mockedList).add("one");
        verify(mockedList).clear();
    }
}
After
package org.openrewrite.java.testing.junit5;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.util.List;

import static org.mockito.Mockito.verify;

public class MockitoTests {
    private AutoCloseable mocks;
    @Mock
    List<String> mockedList;

    @BeforeEach
    public void initMocks() {
        mocks = MockitoAnnotations.openMocks(this);
    }

    @Test
    public void usingAnnotationBasedMock() {

        mockedList.add("one");
        mockedList.clear();

        verify(mockedList).add("one");
        verify(mockedList).clear();
    }

    @AfterEach
    void tearDown() throws Exception {
        mocks.close();
    }
}
java
Unchanged
example
Before
import org.junit.Rule;
import org.junit.contrib.java.lang.system.EnvironmentVariables;
import org.junit.contrib.java.lang.system.ExpectedSystemExit;
import org.junit.contrib.java.lang.system.ProvideSystemProperty;
import org.junit.contrib.java.lang.system.SystemOutRule;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

class CliTest {
    @Rule
    public final ProvideSystemProperty properties = new ProvideSystemProperty("mode", "test");

    @Rule
    public final EnvironmentVariables environment = new EnvironmentVariables();

    @Rule
    public final SystemOutRule out = new SystemOutRule().enableLog().mute();

    @Rule
    public final ExpectedSystemExit exit = ExpectedSystemExit.none();

    @Test
    void printsUsageAndExits() {
        environment.set("HOME", "/tmp");
        exit.expectSystemExitWithStatus(1);
        exit.checkAssertionAfterwards(() -> assertEquals("usage", out.getLog()));
        System.out.print("usage");
        System.exit(1);
    }
}
After
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junitpioneer.jupiter.SetSystemProperty;
import uk.org.webcompere.systemstubs.environment.EnvironmentVariables;
import uk.org.webcompere.systemstubs.jupiter.SystemStub;
import uk.org.webcompere.systemstubs.jupiter.SystemStubsExtension;
import uk.org.webcompere.systemstubs.stream.SystemOut;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static uk.org.webcompere.systemstubs.SystemStubs.catchSystemExit;

@ExtendWith(SystemStubsExtension.class)
@SetSystemProperty(key = "mode", value = "test")
class CliTest {

    @SystemStub
    public final EnvironmentVariables environment = new EnvironmentVariables();

    @SystemStub
    public final SystemOut out = new SystemOut();

    @Test
    void printsUsageAndExits() throws Exception {
        environment.set("HOME", "/tmp");
        int status = catchSystemExit(() -> {
            System.out.print("usage");
            System.exit(1);
        });
        assertEquals(1, status);
        assertEquals("usage", out.getText());
    }
}
java
Before
import org.junit.Test;
import org.junit.experimental.runners.Enclosed;
import org.junit.runner.RunWith;

@RunWith(Enclosed.class)
public class RootTest {
    public static class InnerTest {
        @Test
        public void test() {
        }
    }
}
After
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

public class RootTest {
    @Nested
    public class InnerTest {
        @Test
        public void test() {
        }
    }
}
java
Before
import org.junit.Assert;
import org.junit.Test;

import static java.util.Arrays.asList;
import static org.hamcrest.Matchers.containsInAnyOrder;

public class SampleTest {
    @SuppressWarnings("ALL")
    @Test
    public void filterShouldRemoveUnusedConfig() {
        Assert.assertThat(asList("1", "2", "3"),
                containsInAnyOrder("3", "2", "1"));
    }
}
After
import org.junit.jupiter.api.Test;

import static java.util.Arrays.asList;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.containsInAnyOrder;

public class SampleTest {
    @SuppressWarnings("ALL")
    @Test
    public void filterShouldRemoveUnusedConfig() {
        assertThat(asList("1", "2", "3"),
                containsInAnyOrder("3", "2", "1"));
    }
}
java
Before
package org.openrewrite.java.testing.junit5;

import org.junit.Before;
import org.junit.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.util.List;

import static org.mockito.Mockito.verify;

public class MockitoTests {
    @Mock
    List<String> mockedList;

    @Before
    public void initMocks() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void usingAnnotationBasedMock() {

        mockedList.add("one");
        mockedList.clear();

        verify(mockedList).add("one");
        verify(mockedList).clear();
    }
}
After
package org.openrewrite.java.testing.junit5;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.util.List;

import static org.mockito.Mockito.verify;

public class MockitoTests {
    private AutoCloseable mocks;
    @Mock
    List<String> mockedList;

    @BeforeEach
    public void initMocks() {
        mocks = MockitoAnnotations.openMocks(this);
    }

    @Test
    public void usingAnnotationBasedMock() {

        mockedList.add("one");
        mockedList.clear();

        verify(mockedList).add("one");
        verify(mockedList).clear();
    }

    @AfterEach
    void tearDown() throws Exception {
        mocks.close();
    }
}
java
Unchanged
example
Before
import org.junit.Rule;
import org.junit.contrib.java.lang.system.EnvironmentVariables;
import org.junit.contrib.java.lang.system.ExpectedSystemExit;
import org.junit.contrib.java.lang.system.ProvideSystemProperty;
import org.junit.contrib.java.lang.system.SystemOutRule;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

class CliTest {
    @Rule
    public final ProvideSystemProperty properties = new ProvideSystemProperty("mode", "test");

    @Rule
    public final EnvironmentVariables environment = new EnvironmentVariables();

    @Rule
    public final SystemOutRule out = new SystemOutRule().enableLog().mute();

    @Rule
    public final ExpectedSystemExit exit = ExpectedSystemExit.none();

    @Test
    void printsUsageAndExits() {
        environment.set("HOME", "/tmp");
        exit.expectSystemExitWithStatus(1);
        exit.checkAssertionAfterwards(() -> assertEquals("usage", out.getLog()));
        System.out.print("usage");
        System.exit(1);
    }
}
After
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junitpioneer.jupiter.SetSystemProperty;
import uk.org.webcompere.systemstubs.environment.EnvironmentVariables;
import uk.org.webcompere.systemstubs.jupiter.SystemStub;
import uk.org.webcompere.systemstubs.jupiter.SystemStubsExtension;
import uk.org.webcompere.systemstubs.stream.SystemOut;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static uk.org.webcompere.systemstubs.SystemStubs.catchSystemExit;

@ExtendWith(SystemStubsExtension.class)
@SetSystemProperty(key = "mode", value = "test")
class CliTest {

    @SystemStub
    public final EnvironmentVariables environment = new EnvironmentVariables();

    @SystemStub
    public final SystemOut out = new SystemOut();

    @Test
    void printsUsageAndExits() throws Exception {
        environment.set("HOME", "/tmp");
        int status = catchSystemExit(() -> {
            System.out.print("usage");
            System.exit(1);
        });
        assertEquals(1, status);
        assertEquals("usage", out.getText());
    }
}

Usage​

Run this recipe

This recipe has no required configuration options. Users of Moderne can run it via the Moderne CLI.

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell
mod run . --recipe JUnit4to5Migration

If the recipe is not available locally, then you can install it using:

RELEASE resolves to the newest release and LATEST to the newest build of any kind, including snapshots. Either one lets mod config recipes upgrade pull in later versions without editing this command; a pinned version stays where you put it.

mod config recipes jar install org.openrewrite.recipe:rewrite-testing-frameworks:RELEASE

Data tables​

PowerMock tests disabled for manual migration
org.openrewrite.java.testing.mockito.table.PowerMockTestsDisabled

Tests disabled because they use a PowerMock feature with no Mockito equivalent. Each row is an action item: rework the test so it does not reach into private members, then re-enable it.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.java.testing.mockito.table.PowerMockTestsDisabled
ColumnDescription
Source pathThe path of the test source file.
Test classThe test class the disabled test belongs to.
Disabled elementThe test method that was disabled, or the class name when the usage sits outside a test method and the whole class had to be disabled.
ScopeMETHOD when a single test was disabled, CLASS when the whole test class was.
ReasonThe PowerMock usage that cannot be migrated.
Maven metadata failures
org.openrewrite.maven.table.MavenMetadataFailures

Attempts to resolve maven metadata that failed.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.maven.table.MavenMetadataFailures
ColumnDescription
Group idThe groupId of the artifact for which the metadata download failed.
Artifact idThe artifactId of the artifact for which the metadata download failed.
VersionThe version of the artifact for which the metadata download failed.
Maven repositoryThe URL of the Maven repository that the metadata download failed on.
SnapshotsDoes the repository support snapshots.
ReleasesDoes the repository support releases.
FailureThe reason the metadata download failed.
Source files that had results
org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileResults
ColumnDescription
Source path before the runThe source path of the file before the run. null when a source file was created during the run.
Source path after the runA recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changesIn a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changesThe specific recipe that made a change.
Estimated time savingAn estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
CycleThe recipe cycle in which the change was made.
Source files that had search results
org.openrewrite.table.SearchResults

Search results that were found during the recipe run.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SearchResults
ColumnDescription
Source path of search result before the runThe source path of the file with the search result markers present.
Source path of search result after run the runA recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
ResultThe trimmed printed tree of the LST element that the marker is attached to.
DescriptionThe content of the description of the marker.
Recipe that added the search markerThe specific recipe that added the Search marker.
Source files that errored on a recipe
org.openrewrite.table.SourcesFileErrors

The details of all errors produced by a recipe run.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileErrors
ColumnDescription
Source pathThe file that failed to parse.
Recipe that made changesThe specific recipe that made a change.
Stack traceThe stack trace of the failure.
Recipe performance
org.openrewrite.table.RecipeRunStats

Statistics used in analyzing the performance of recipes.

Export after a run
mod study . --last-recipe-run \
  --data-table org.openrewrite.table.RecipeRunStats
ColumnDescription
The recipeThe recipe whose stats are being measured both individually and cumulatively.
Source file countThe number of source files the recipe ran over.
Source file changed countThe number of source files which were changed in the recipe run. Includes files created, deleted, and edited.
Cumulative scanning time (ns)The total time spent across the scanning phase of this recipe.
Max scanning time (ns)The max time scanning any one source file.
Cumulative edit time (ns)The total time spent across the editing phase of this recipe.
Max edit time (ns)The max time editing any one source file.