Validate All Images in Array.

validateImage.js

import fetchImage from 'https://gist.githubusercontent.com/gabemeola/27e8fd9148f9ae7541d88d54d87f5113/raw/97138b8039f3b598c41832ef4bfdd4e48bcb3ab6/fetchImage.js'


const noop = () => {}

function removeUrlProtocol(url) {
    // Split the image to not include protocol
    const srcSplit = url.split(':');
    // Use the second part of the protocol string
    // split, if it exists.
    return srcSplit[1] ? srcSplit[1] : srcSplit[0];
}


/**
 * Takes an Array on Images and returns
 * which images a valid.
 *
 * Can be configure with a custom config object.
 *
 * @param {Array.<string>} images - Images to validate
 * @param {Object=} [config] - Configuration object
 * @param {number | null} [config.validateLimit = null] - Limit on validation loop. Starting at beginning of Array
 * @param {boolean} [config.stopOnFound = false] - Whether to stop once an image is found.
 *                                                 Not guarantied because ~Promises~.
 * @return {Promise.<Array<string>>} - Array of valid images
 */
export default async function validateImages(images, {
    validateLimit = null,
    stopOnFound = false,
} = {}) {
    let found = false;
    const imagePromises = [];
    
    const foundSwitcher = (imageUrl) => {
        found = true;
        return imageUrl;
    };

    for (let i = 0; i < images.length; i += 1) {
        const image = removeUrlProtocol(images[i]);

        // Break out if we reached the limit
        if (i === validateLimit - 1) break;
        // Break out if we found an image,
        // and this functionality is turned on.
        // We wil most likely get more than one image found
        // because Promises are async.
        if (stopOnFound && found) break;


        const fetchPromise = fetchImage(image)
            .then(foundSwitcher)
            .catch(noop);

        imagePromises.push(fetchPromise);
    }


    return Promise
        .all(imagePromises)
        .then((res) => res.filter(Boolean))
        .catch((e) => {
            // Re-throw error
            throw e;
        });
}