message: Use function instead of arrow for addAssertionErrors
diff: @@ -42,7 +42,7 @@ const addSuppressedErrors = result => {
  }
  };
  -const addAssertionErrors = result => {
  +function addAssertionErrors(result) {
  const {assertionCalls, assertionsExpected} = getState();
  setState({
  assertionCalls: 0,
  