responsive-images-resizer/resize.js

Minify and resize images to an array of resolutions

const path = require("path");
const createResolutionFolders = require("./lib/createResolutionFolders");
const sharp = require("sharp");

class workImage {
    constructor(image, sizes) {
        this.image = image;
        this.sizes = sizes;
        this.extension = image.substring(image.lastIndexOf("."));
        this.writePath = path.join(image, "..");
        createResolutionFolders(path.join(image, ".."), sizes);
    }

    getOutputName(size) {
        return this.image + size;
    }

    getImageName(size) {
        const imageName = this.image.substring(
            this.image.lastIndexOf("/") + 1,
            this.image.length
        );
        const extension = imageName.substring(imageName.lastIndexOf("."));
        const withoutExtension = imageName.substring(
            0,
            imageName.lastIndexOf(".")
        );
        const imageNameWithSize =
            withoutExtension + "-" + size.toString() + extension;
        return imageNameWithSize;
    }

    getWritePath(size) {
        return this.writePath + "\\" + size + "\\";
    }

    async workImages() {
        for (let i = 0; i < this.sizes.length; i++) {
            await this.workImage(this.sizes[i]);
        }
        return true;
    }

    workImage(size) {
        return new Promise((resolve, reject) => {
            sharp(this.image)
                .resize(parseInt(size, 10))
                .toFile(
                    this.getWritePath(size) + this.getImageName(size),
                    (err, info) => {
                        if (err) {
                            reject(err);
                        } else {
                            resolve(info);
                        }
                    }
                );
        });
    }
}

async function resize(absoluteNameArray, sizeArray) {
    let promDone = 0;
    return await new Promise((resolve, reject) => {
        for (let i = 0; i < absoluteNameArray.length; i++) {
            const work = new workImage(absoluteNameArray[i], sizeArray);
            work.workImages()
                .then(success => {
                    promDone = promDone + 1;
                    if (promDone === absoluteNameArray.length) {
                        resolve(true);
                    }
                })
                .catch(err => {
                    reject(err);
                });
        }
    });
}

module.exports = resize;