Test cleanup

Recipes to simplify assertions and clean up test code.

Composite Recipes

Recipes that include further recipes, often including the individual recipes below.

• Replace JUnit assertTrue(false) and assertFalse(true) with fail()
• Testing best practices

Recipes

• Assertion arguments should be passed in the correct order
• Include an assertion in tests
• Junit assertTrue(a == b) to assertEquals(a,b)
• Kotlin test methods should have return type Unit
• Remove JUnit assertTrue(true) and assertFalse(false)
• Remove empty tests without comments
• Remove public visibility of JUnit 5 tests
• Remove test prefix from JUnit 5 tests
• Remove unnecessary assertEquals delta argument for integral types
• Replace JUnit assertEquals(false, <boolean>) to assertFalse(<boolean>) / assertTrue(<boolean>)
• Replace JUnit assertFalse(!<boolean>) to assertTrue(<boolean>)
• Replace JUnit assertFalse(a == null) to assertNotNull(a)
• Replace JUnit assertFalse(a.equals(b)) to assertNotEquals(a,b)
• Replace JUnit assertNotEquals(false, <boolean>) to assertFalse(<boolean>) / assertTrue(<boolean>)
• Replace JUnit assertTrue(!<boolean>) to assertFalse(<boolean>)
• Replace JUnit assertTrue(a == null) to assertNull(a)
• Replace JUnit assertTrue(a.equals(b)) to assertEquals(a,b)
• Replace JUnit assertTrue(false) and assertFalse(true) with fail()
• Replace JUnit assertTrue(false, "reason") and assertFalse(true, "reason") with fail("reason")
• Simplify throws statements of tests
• Test methods should have void return type
• assertEquals(a, null) to assertNull(a)