JUnit 6

Thanks to the Sovereign Tech Fund I had the opportunity to work full-time on JUnit this year. In this talk, I‘ll report on my experiences and walk you through the new features and enhancements. Most prominently, those are Open Test Reporting, Parameterized Test Classes, Discovery Issues, and the new Java 17 and Kotlin 2.1 baselines.

Transcript

1. JUnit 6.0 1
2. Marc Philipp 2
3. JUnit in a nutshell • • • • • 3
4. Thank you to our sponsors! 4
5. The Sovereign Tech Fund is investing in JUnit in 2024 and 2025! 5
6. Sovereign Tech Fund • • 6
7. JUnit Generations 7
8. JUnit Generations 7.1
9. JUnit Generations 7.2
10. JUnit Generations 7.3
11. Full-time work on JUnit (2024-2025) 8
12. Full-time work on JUnit (2024-2025) • 8.1
13. Full-time work on JUnit (2024-2025) • • 8.2
14. Full-time work on JUnit (2024-2025) • • • 8.3
15. Full-time work on JUnit (2024-2025) • • • • 8.4
16. Full-time work on JUnit (2024-2025) • • • • • 8.5
17. Full-time work on JUnit (2024-2025) • • • • • • 8.6
18. Full-time work on JUnit (2024-2025) • • • • • • • 8.7
19. Today’s Agenda 9
20. More info • • 10
21. Better Test Reports 11
22. Open Test Reporting XML format • • junit-platform- reporting • junit.platform.reporting.open.xml.enabled=true 12
23. Event-based format <?xml version="1.0" ?> <e:events xmlns="https:��schemas.opentest4j.org/reporting/core/0.1.0" xmlns:e="https:��schemas.opentest4j.o <infrastructure><hostName>�����hostName><userName>marc��userName><operatingSystem>Mac OS X��operatingSystem <e:started id="766" name="JUnit Jupiter" time="2022-09-23T07:54:50.324086Z"><metadata><junit:uniqueId <e:started id="767" name="ColorPaletteTests" parentId="766" time="2022-09-23T07:54:50.324275Z"><metadata <e:started id="768" name="DemonstratePalettesTests" parentId="767" time="2022-09-23T07:54:50.324456Z" <e:started id="769" name="flat_default()" parentId="768" time="2022-09-23T07:54:50.324589Z"><metadata <e:finished id="769" time="2022-09-23T07:54:50.326039Z"><result status="SUCCESSFUL">��result>��e:finished <e:finished id="768" time="2022-09-23T07:54:50.332254Z"><result status="SUCCESSFUL">��result>��e:finished <e:finished id="767" time="2022-09-23T07:54:50.333862Z"><result status="SUCCESSFUL">��result>��e:finished <e:finished id="766" time="2022-09-23T07:54:50.812066Z"><result status="SUCCESSFUL">��result>��e:finished ��e:events> 13
24. Hierarchical format <?xml version="1.0" encoding="UTF-8" standalone="no"?> <h:execution xmlns:h="https:��schemas.opentest4j.org/reporting/hierarchy/0.1.0" xmlns="https:��schemas.open <infrastructure>���� ��� �����infrastructure> <h:root duration="PT0.48798S" name="JUnit Jupiter" start="2022-09-23T07:54:50.324086Z"> <metadata> <junit:uniqueId>[engine:junit-jupiter]��junit:uniqueId> <junit:legacyReportingName>JUnit Jupiter��junit:legacyReportingName> <junit:type>CONTAINER��junit:type> ��metadata> <result status="SUCCESSFUL"�� <h:child duration="PT0.009587S" name="ColorPaletteTests" start="2022-09-23T07:54:50.324275Z"> <metadata>���� ��� �����metadata> <sources><java:classSource className="org.junit.platform.console.tasks.ColorPaletteTests"���� <result status="SUCCESSFUL"�� <h:child duration="PT0.007798S" name="DemonstratePalettesTests" start="2022-09-23T07:54:50.324456Z" <metadata>���� ��� �����metadata> <sources><java:classSource className="org.junit.platform.console.tasks.ColorPaletteTests$Demonstrat <result status="SUCCESSFUL"�� <h:child duration="PT0.00145S" name="flat_default()" start="2022-09-23T07:54:50.324589Z"> <metadata>���� ��� �����metadata> <sources><java:methodSource className="org.junit.platform.console.tasks.ColorPaletteTests$Demonst <result status="SUCCESSFUL"�� ��h:child> ��h:child> 14
25. HTML Report • • 15
26. HTML Report 16
27. HTML Report 17
28. Demo 18
29. Platform-agnostic and extensible • • 19
30. Future work • • • 20
31. Parameterized Test Classes 21
32. Parameterized Test Methods • @ParameterizedTest • @���Source class SomeTests { @ParameterizedTest @ValueSource(strings = {"foo", "bar"}) void shouldNotBeNull(String value) { assertNotNull(value); } @ParameterizedTest @ValueSource(strings = {"foo", "bar"}) void lengthShouldBeThree() { assertEquals(3, value.length()); } } 22
33. Parameterized Test Classes • @ParameterizedClass • @���Source @ParameterizedClass @ValueSource(strings = {"foo", "bar"}) class SomeTests { @Parameter String value; @Test void shouldNotBeNull() { assertNotNull(value); } @Test void lengthShouldBeThree() { assertEquals(3, value.length()); } } 23
34. Consuming Arguments • • @ParameterizedClass @ValueSource(strings = {"foo", "bar"}) record SomeTests(String value) { @Test void shouldNotBeNull() { assertNotNull(value); } @Test void lengthShouldBeThree() { assertEquals(3, value.length()); } } 24
35. Demo 25
36. Mutable vs. immutable arguments • • @AfterEach ▪ @ParameterizedClass 26
37. Argument Source Annotations • @ValueSource @EnumSource @NullSource @EmptySource • @CsvSource @CsvFileSource • @MethodSource @FieldSource • @ArgumentsSource(MyProvider.class) 27
38. Lifecycle Methods • @BeforeParameterizedClassInvocation @AfterParameterizedClassInvocation • @BeforeParameterizedClassInvocation static void before(List<String> list) { if (list instanceof ArrayList<?> arrayList) { arrayList.ensureCapacity(100); } } 28
39. Discovery Issues 29
40. Discovery issues? 30
41. Valid test methods? @Test �� Java int test() { return 42; } @Test �� Kotlin fun test(): Nothing = fail() 31
42. Valid test methods? @Test �� Java int test() { return 42; } @Test �� Kotlin fun test(): Nothing = fail() @Test void Unit 31.1
43. Malformed declarations • • • 32
44. Discovery issue reporting • • • • junit.platform.discovery.issue.severity.critical 33
45. Discovery issue reporting 34
46. Demo 35
47. JUnit 6.0 36
48. Overview of 6.0 • ▪ ▪ • 37
49. Major changes in 6.0 38
50. Major changes in 6.0 • 38.1
51. Major changes in 6.0 • • 38.2
52. Major changes in 6.0 • • • @Nullable 38.3
53. Major changes in 6.0 • • • @Nullable • 38.4
54. Major changes in 6.0 • • • @Nullable • • 38.5
55. Major changes in 6.0 • • • @Nullable • • ▪ 38.6
56. Major changes in 6.0 • • • @Nullable • • ▪ • 38.7
57. Long(er)-Term Support for 5.14.x • • 39
58. Spring Framework 7.0 and Spring Boot 4.0 are based on JUnit 6.0 40
59. Example Code and Slides • • 41
60. Q & A 42
61. Thanks! 43