== Why is this an issue?

JUnit assertions should not be made from the `run` method of a `Runnable`, because their failure may not be detected in the test that initiated them.
Failed assertions throw assertion errors.
However, if the error is thrown from another thread than the one that initiated the test, the thread will exit but the test will not fail.




== How to fix it
Assertions in `Runnable` tasks should be extracted or executed by the main thread to make the whole test fail.

=== Code examples
==== Noncompliant code example

[source,java,diff-id=1,type=noncompliant]
----
class RunnableWithAnAssertion extends Thread {
  @Override
  public void run() {
    Assert.assertEquals(expected, actual);  // Noncompliant
  }

  @Test
  void test() {
    RunnableWithAnAssertion otherThread = new RunnableWithAnAssertion();
    otherThread.start(); // The assertion in the run method above will be executed by other thread than the current one
    // ...
    // Perform some actions that do not make the test fail
    // ...
    Assert.assertTrue(true);
  }
}
----
==== Compliant solution
[source,java,diff-id=1,type=compliant]
----
class RunnableWithAnAssertion extends Thread {
  @Override
  public void run() {
    Assert.assertEquals(expected, actual);  // Noncompliant
  }

  @Test
  void test() {
    RunnableWithAnAssertion otherThread = new RunnableWithAnAssertion();
    otherThread.run();
    // ...
    // The failed assertions in the run method will prevent us from reaching the assertion below
    // ...
    Assert.assertTrue(true);
  }
}
----


ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Remove this assertion.


'''
== Comments And Links
(visible only on this page)

=== on 22 Oct 2014, 19:20:32 Ann Campbell wrote:
Note that Applicability is marked only for Tests

=== on 24 Nov 2014, 19:33:09 Nicolas Peru wrote:
I am guessing here and so the answer should probably part of the RSPEC : The run method is a run method of a Thread class ? 

=== on 22 Apr 2015, 11:01:15 Ann Campbell wrote:
Since you're already implementing this [~nicolas.peru], I'm guessing it's okay.

=== on 22 Apr 2015, 11:20:20 Nicolas Peru wrote:
\[~ann.campbell.2]yes, more especially with the the mention of ``++Runnable++``

endif::env-github,rspecator-view[]
