How to let espresso tests fail for a specific condition

Issue

For my espresso tests, I am searching for a way to let all tests fail before they run, if a specific condition is not met. How can I achieve this?

Solution

How about creating a jUnit rule to handle that? Specifically the Verifier rule. https://github.com/junit-team/junit4/wiki/rules#verifier-rule

Verifier is a base class for Rules like ErrorCollector, which can turn otherwise passing test methods into failing tests if a verification check is failed.

private static String sequence;

public static class UsesVerifier {
  @Rule
  public final Verifier collector = new Verifier() {
    @Override
    protected void verify() {
      sequence += "verify ";
    }
  };

  @Test
  public void example() {
    sequence += "test ";
  }

  @Test
  public void verifierRunsAfterTest() {
    sequence = "";
    assertThat(testResult(UsesVerifier.class), isSuccessful());
    assertEquals("test verify ", sequence);
  }

}

Answered By - Szymon K.