I have this error Expected to return a value at the end of arrow function consistent-return. Im not sure how I can prevent this.

Im trying to stop the Swiper carousel when the screen-size is below 1060px

    import Swiper from 'swiper';

    export default function () {
      let articlesGalleryCarousel;

      const doSomething = () => {
        const enableSwiper = () => {
          articlesGalleryCarousel = new Swiper('.js-swiper-container', {
            loop: true,
            slidesPerView: 'auto',
            centeredSlides: true,
            a11y: true,
            keyboardControl: true,
            grabCursor: true,
            pagination: '.swiper-pagination',
            paginationClickable: true,
            navigation: {
              nextEl: '.carousel-button--prev',
              prevEl: '.carousel-button--next',
            },
          });
        };

        const breakpoint = window.matchMedia('(max-width:1060px)');

        const breakpointChecker = () => {
          if (breakpoint.matches === true) {
            if (articlesGalleryCarousel !== undefined) articlesGalleryCarousel.destroy(true, true);
          } else if (breakpoint.matches === false) {
            return enableSwiper();
          }
        };

        breakpoint.addListener(breakpointChecker);

        breakpointChecker();
      };
      return doSomething;
    }

I have this error Expected to return a value at the end of arrow function consistent-return. Im not sure how I can prevent this.

Im trying to stop the Swiper carousel when the screen-size is below 1060px

    import Swiper from 'swiper';

    export default function () {
      let articlesGalleryCarousel;

      const doSomething = () => {
        const enableSwiper = () => {
          articlesGalleryCarousel = new Swiper('.js-swiper-container', {
            loop: true,
            slidesPerView: 'auto',
            centeredSlides: true,
            a11y: true,
            keyboardControl: true,
            grabCursor: true,
            pagination: '.swiper-pagination',
            paginationClickable: true,
            navigation: {
              nextEl: '.carousel-button--prev',
              prevEl: '.carousel-button--next',
            },
          });
        };

        const breakpoint = window.matchMedia('(max-width:1060px)');

        const breakpointChecker = () => {
          if (breakpoint.matches === true) {
            if (articlesGalleryCarousel !== undefined) articlesGalleryCarousel.destroy(true, true);
          } else if (breakpoint.matches === false) {
            return enableSwiper();
          }
        };

        breakpoint.addListener(breakpointChecker);

        breakpointChecker();
      };
      return doSomething;
    }

• javascript
• ecmascript-6

• 26:34 error Expected to return a value at the end of arrow function consistent-return This is the error im getting – Antony Moss Commented Dec 28, 2018 at 15:30

2 Answers 2

This is an ESLint consistent-return warning.

"This rule requires return statements to either always or never specify values"

Your function "breakpointChecker" did not returns something in case of the first IF statement.

ESLint is telling you that an arrow function should always or never return a value.

You have one branch that returns a value (return enableSwiper();) and one that doesn't (if breakpoint.matches is true).

So -- do you want that function to always return a value or to never return a value?