Function processResult

packages/expect/src/index.ts:310–351

(
      result: SyncExpectationResult,
      asyncError?: JestAssertionError,
    )

    };

    const processResult = (
      result: SyncExpectationResult,
      asyncError?: JestAssertionError,
    ) => {
      _validateResult(result);

      getState().assertionCalls++;

      if ((result.pass && isNot) || (!result.pass && !isNot)) {
        // XOR
        const message = getMessage(result.message);
        let error;

        if (err) {
          error = err;
          error.message = message;
        } else if (asyncError) {
          error = asyncError;
          error.message = message;
        } else {
          error = new JestAssertionError(message);

          // Try to remove this function from the stack trace frame.
          // Guard for some environments (browsers) that do not support this feature.
          if (Error.captureStackTrace) {
            Error.captureStackTrace(error, throwingMatcher);
          }
        }
        // Passing the result of the matcher with the error so that a custom
        // reporter could access the actual and expected objects of the result
        // for example in order to display a custom visual diff
        error.matcherResult = {...result, message};

        if (throws) {
          throw error;
        } else {
          getState().suppressedErrors.push(error);
        }
      } else {
        getState().numPassingAsserts++;
      }
    };

    const handleError = (error: Error) => {
      if (