JAVA中单元测试的常用方式(小结)

class StandardTests {

  @BeforeAll
  static void initAll() {
  }

  @BeforeEach
  void init() {
  }

  @Test
  void succeedingTest() {
  }

  @Test
  void failingTest() {
    fail("a failing test");
  }

  @Test
  @Disabled("for demonstration purposes")
  void skippedTest() {
    // not executed
  }

  @Test
  void abortedTest() {
    assumeTrue("abc".contains("Z"));
    fail("test should have been aborted");
  }

  @AfterEach
  void tearDown() {
  }

  @AfterAll
  static void tearDownAll() {
  }

}

// entry point for all assertThat methods and utility methods (e.g. entry)
import static org.assertj.core.api.Assertions.*;

// basic assertions
assertThat(frodo.getName()).isEqualTo("Frodo");
assertThat(frodo).isNotEqualTo(sauron);

// chaining string specific assertions
assertThat(frodo.getName()).startsWith("Fro")
              .endsWith("do")
              .isEqualToIgnoringCase("frodo");

// collection specific assertions (there are plenty more)
// in the examples below fellowshipOfTheRing is a List
assertThat(fellowshipOfTheRing).hasSize(9)
                .contains(frodo, sam)
                .doesNotContain(sauron);

// as() is used to describe the test and will be shown before the error message
assertThat(frodo.getAge()).as("check %s's age", frodo.getName()).isEqualTo(33);

// Java 8 exception assertion, standard style ...
assertThatThrownBy(() -> { throw new Exception("boom!"); }).hasMessage("boom!");
// ... or BDD style
Throwable thrown = catchThrowable(() -> { throw new Exception("boom!"); });
assertThat(thrown).hasMessageContaining("boom");

// using the 'extracting' feature to check fellowshipOfTheRing character's names (Java 7)
assertThat(fellowshipOfTheRing).extracting("name")
                .contains("Boromir", "Gandalf", "Frodo", "Legolas")
// same thing using a Java 8 method reference
assertThat(fellowshipOfTheRing).extracting(TolkienCharacter::getName)
                .doesNotContain("Sauron", "Elrond");

// extracting multiple values at once grouped in tuples (Java 7)
assertThat(fellowshipOfTheRing).extracting("name", "age", "race.name")
                .contains(tuple("Boromir", 37, "Man"),
                     tuple("Sam", 38, "Hobbit"),
                     tuple("Legolas", 1000, "Elf"));

// filtering a collection before asserting in Java 7 ... 
assertThat(fellowshipOfTheRing).filteredOn("race", HOBBIT)
                .containsOnly(sam, frodo, pippin, merry);
// ... or in Java 8
assertThat(fellowshipOfTheRing).filteredOn(character -> character.getName().contains("o"))
                .containsOnly(aragorn, frodo, legolas, boromir);

// combining filtering and extraction (yes we can)
assertThat(fellowshipOfTheRing).filteredOn(character -> character.getName().contains("o"))
                .containsOnly(aragorn, frodo, legolas, boromir)
                .extracting(character -> character.getRace().getName())
                .contains("Hobbit", "Elf", "Man");

// and many more assertions: iterable, stream, array, map, dates (java 7 and 8), path, file, numbers, predicate, optional ...

// You can mock concrete classes and interfaces
TrainSeats seats = mock(TrainSeats.class);

// stubbing appears before the actual execution
when(seats.book(Seat.near(WINDOW).in(FIRST_CLASS))).thenReturn(BOOKED);

// the following prints "BOOKED"
System.out.println(seats.book(Seat.near(WINDOW).in(FIRST_CLASS)));

// the following prints "null" because 
// .book(Seat.near(AISLE).in(FIRST_CLASS))) was not stubbed
System.out.println(seats.book(Seat.near(AISLE).in(FIRST_CLASS)));

// the following verification passes because 
// .book(Seat.near(WINDOW).in(FIRST_CLASS)) has been invoked
verify(seats).book(Seat.near(WINDOW).in(FIRST_CLASS));

// the following verification fails because 
// .book(Seat.in(SECOND_CLASS)) has not been invoked
verify(seats).book(Seat.in(SECOND_CLASS));