JJUG CCC Spring 2018 memo

I didn't post ...

Still to come! Introduction to JUnit 5 / Ryo Shindo

• JUnit5 --Successor version of Junit4 --September 2017 GA
  • JDK baseline 8+

--What you want from the test framework (important element) --Conciseness and readability

• Consistency
• Scalability --What's better about Junit 5 --The important elements are getting better
• Junit5 demerit
  • 1.8+ --Package is different --Major unusual structured test / parameterized test --Various FW and IDE support

Setup (different)

---- Multi-module configuration (Junit 5 has 3 configurations!) --junit platform (test execution platform) --Does not work on launcher, IDE --junit jupitaer (new test API) ―― @Test - junit vintage --Migration support

Junit5.2 → Bill of Materials -It provides a good combination of module versions of ↑

What changed in the way the test was written

Petit changed

• @test
  • 4 public only --5 Non-public classes / methods are also OK
• 4 @BeforeClass/@before?
• 5 @BeforeAll/@BeforeEach --No distinction between before / after
• @ignore -> @Disabled

--Test method name -4 Test name = test method name - 5 @DisplayName

Quite changed (a nice new feature)

--Assertion - assertEquals --The order of arguments changes --Assertion grouping ―― 4 When there are multiple assertions in one test (@Test), if one mistake is made, the subsequent ones will not be executed. ―― 5 Will be executed! --assertAll () Multiply by lambda expression! All asserts and returns OK if all are OK --Exception validation - 4 @Test(expected = ...Exception.class) or try-catch -5 assertThrows (, describe the processing that will occur in the lambda expression)

Structured test / parameterized test

--Structure test ―― 4 public static class-> Inner class (group) for testing ―― 5 Inner class and test method can coexist using @ Nested

--Parameterization test -4 @Runwith (Theories.class ... test runner) @DAtaPoints`` @Theory - 5 junit-jupiter-param module / --... Parameterized test A function to put parameters in the arguments of the test method and turn them automatically.

Extended model

--How to extend the test class - 4 Runnner (@Runwith), Rule --5 @ExtendsWith, multiple specifications allowed

migration

1. Rewrite --Change argument of assertEquals ... --Rule and Runner are rewritten as Extension
2. Migration module (using Junit vintage)