Function toHaveLength

packages/expect/src/matchers.ts:656–709

(received: any, expected: number)

  },

  toHaveLength(received: any, expected: number) {
    const matcherName = 'toHaveLength';
    const isNot = this.isNot;
    const options: MatcherHintOptions = {
      isNot,
      promise: this.promise,
    };

    if (typeof received?.length !== 'number') {
      throw new TypeError(
        matcherErrorMessage(
          matcherHint(matcherName, undefined, undefined, options),
          `${RECEIVED_COLOR(
            'received',
          )} value must have a length property whose value must be a number`,
          printWithType('Received', received, printReceived),
        ),
      );
    }

    ensureExpectedIsNonNegativeInteger(expected, matcherName, options);

    const pass = received.length === expected;

    const message = () => {
      const labelExpected = 'Expected length';
      const labelReceivedLength = 'Received length';
      const labelReceivedValue = `Received ${getType(received)}`;
      const printLabel = getLabelPrinter(
        labelExpected,
        labelReceivedLength,
        labelReceivedValue,
      );

      return (
        // eslint-disable-next-line prefer-template
        matcherHint(matcherName, undefined, undefined, options) +
        '\n\n' +
        `${printLabel(labelExpected)}${isNot ? 'not ' : ''}${printExpected(
          expected,
        )}\n` +
        (isNot
          ? ''
          : `${printLabel(labelReceivedLength)}${printReceived(
              received.length,
            )}\n`) +
        `${printLabel(labelReceivedValue)}${isNot ? '    ' : ''}${printReceived(
          received,
        )}`
      );
    };

    return {message, pass};
  },

  toHaveProperty(
    received: object,