JUnit to Spock Converter

JUnit to Spock Converter is a plug-in for IntelliJ IDEA: https://plugins.jetbrains.com/plugin/12335-groovyfier.

It’s inspired by junit2spock and has the same goal: Facilitate the transition from JUnit to Spock. The advantage compared to the command line tool is the integration in the IDE. The project is in an early stage and has at the moment only a subset of the features of junit2spock.

After converting your JUnit test to a spock specification it probably will not be 100% correct, but it will save you a lot of stupid conversion work.

Features

The following can be replaced:

Table 1. test method → feature method

JUnit 4 / 5	Spock
@Test public void assertOnly() { assertNotNull(book); }	def "assert only"() { expect: book != null }

Table 2. Replace Setup/Cleanup annotations

JUnit 4 / 5	Spock
@BeforeClass / @BeforeAll public static void beforeClass() { } @AfterClass / @AfterAll public static void afterClass() { } @Before / @BeforeEach public void setUp() { } @After / @AfterEach public void tearDown() { }	def setupSpec() { } def cleanupSpec() { } def setup() { } def cleanup() { }

Table 3. Replace assertions, messages convert to comments

JUnit 4 / 5	Spock
assertNotNull(book); assertNull(book.getPages()); assertEquals((Integer) 33, book.getPages()); assertTrue(book.getPages() > 0); assertFalse(book.getPages() < 0); assertNotNull("book is present", book);	book != null book.pages == null book.pages == (Integer) 33 book.pages > 0 !(book.pages < 0) book != null // "book is present"

Table 4. Expected exceptions → thrown

JUnit 4 (only)	Spock
@Test(expected = IllegalArgumentException.class) public void expectArgumentException() { book.setPages(-1); }	def "expect argument exception"() { when: book.pages = -1 then: thrown(IllegalArgumentException) }

Limitations

The following is not (yet) possible:

• Spock is not added by the plugin to your build system (pom.xml or build.gradle). Have a look at spock-example/pom.xml at spock-1.x · spockframework/spock-example or the more minimalistic version in this test project: java-groovy-sample/pom.xml.

• Junit 5: assertThrows

• Java lambdas are not converted to Groovy closures

Roadmap

• Documentation

  • Commit converted test to show what works and what not: BookTest

  • Plugin description with small video like IntelliJ new features

• Quality

  • Unit Tests for plugin itself

• Separate code, so that it can be easily extended with new features and it’s easier to provide pull requests.

• Framework support

  • Mockito

  • Wicket

  • Hamcrest

• Spock features

  • create data driven tests if test contains only similar assertions