CODEWITHSUNDEEP
javatestng
Ori Marko
Ori Marko

Reputation: 58774

TestNG BeforeMethod's firstTimeOnly usage

What is the usage of TestNG BeforeMethod's firstTimeOnly optional element?

If true and the @Test method about to be run has an invocationCount > 1, this BeforeMethod will only be invoked once (before the first test invocation).

It seems redundant as using @BeforeTest which is more clear

@BeforeTest: The annotated method will be run before any test method belonging to the classes inside the tag is run.

Upvotes: 0

Views: 655

Answers (1)

Magnilex
Magnilex

Reputation: 11958

@BeforeMethod is invoked before each test, while @BeforeTest is invoked once, before any test has yet been executed.

So, it makes no sense having a firstTimeOnly property on @BeforeTest, it will only ever be executed once per group of tests, by design.

On the other hand, since @BeforeMethod is possibly executed several times (if test methods are executed several times using invocationCount), it is possible to tell TestNG to only execute the method annotated with BeforeMethod once.

This answer has a good example on the difference between the two annotations.

Let's illustrate the behaviour with an example:

public class TestClass {

  @Test(invocationCount = 2)
  public void methodOne() {
    System.out.println("executing method one");
  }

  @Test
  public void methodTwo() {
    System.out.println("executing method one");
  }

  @BeforeMethod
  public void beforeMethod() {
    System.out.println("before method");
  }

  @BeforeTest
  public void beforeTest() {
    System.out.println("before test");
  }

}

This prints:

before test
before method
executing method one
before method
executing method one
before method
executing method one

Notice that beforeMethod() is executed before each method, while beforeMethod is executed once, before any test has yet been executed. Also notice that beforeMethod is executed before each execution of methodOne().

Now, let's add the firstTimeOnly property:

@BeforeMethod(firstTimeOnly = true)

before test
before method
executing method one
executing method one
before method
executing method one

Now, beforeMethod() is only executed once before methodOne(), even though the test is executed twice.

Upvotes: 1

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