Method expect_fail

test/common.py:1298–1314

Run a subprocess and assert that it returns non-zero. Return the stderr of the subprocess.

(self, cmd, expect_traceback=False, **kwargs)

  # Shared test code between main suite and others

  def expect_fail(self, cmd, expect_traceback=False, **kwargs):
    """Run a subprocess and assert that it returns non-zero.

    Return the stderr of the subprocess.
    """
    proc = self.run_process(cmd, check=False, stderr=PIPE, **kwargs)
    self.assertNotEqual(proc.returncode, 0, 'subprocess unexpectedly succeeded. stderr:\n' + proc.stderr)
    # When we check for failure we expect a user-visible error, not a traceback.
    # However, on windows a python traceback can happen randomly sometimes,
    # due to "Access is denied" https://github.com/emscripten-core/emscripten/issues/718
    if expect_traceback:
      self.assertContained('Traceback', proc.stderr)
    elif not WINDOWS or 'Access is denied' not in proc.stderr:
      self.assertNotContained('Traceback', proc.stderr)
    if EMTEST_VERBOSE:
      sys.stderr.write(proc.stderr)
    return proc.stderr

  def assert_fail(self, cmd, expected, **kwargs):
    """Just like expect_fail, but also check for expected message in stderr."""