ImageProcessing.js

/**
 * Created by Tu Huynh on 8/17/2017.
 */

let resemble = require('node-resemble-js')
    , fs = require('fs')
    , jimp = require("jimp")
    , shell = require('shelljs');

class ImageProcessing {

    static getDeviceScreenInfo(udid) {
        let deviceDensity = shell.exec(`adb -s ${udid} shell wm density`, {async: false, silent: true}).stdout;
        let deviceResolution = shell.exec(`adb -s ${udid} shell wm size`, {async: false, silent: true}).stdout;

        let deviceScreenInfo = {};
        deviceScreenInfo.density = deviceDensity.replace("Physical density: ", "").trim();
        deviceScreenInfo.resolution = deviceResolution.replace("Physical size: ", "").trim();

        return deviceScreenInfo;
    }

    static crop(inputFile, left, top, right, bottom, outputFile, deviceInfo, screenName) {
        let folders = {
            diffFolderPath: 'screenshots/diff/',
            referenceFolderPath: 'screenshots/reference/',
            screenFolderPath: 'screenshots/screen/'
        };
        let takenImageName = `${deviceInfo.resolution}_${deviceInfo.density}_${screenName}.png`;

        this.createFolders();

        return new Promise((resolve, reject) => {
            jimp.read(inputFile, function (err, image) {
                if (err) {
                    reject(err);
                    return;
                }
                image
                    .crop(left, top, right, bottom)
                    .write(outputFile, (err, image) => {
                        resolve(image);
                        if (!fs.existsSync(`${folders.referenceFolderPath}${takenImageName}`)) {
                            shell.cp(`${folders.screenFolderPath}${takenImageName}`, `${folders.referenceFolderPath}`);
                        }
                    });
            });
        });
    }

    static compare(targetImage, referenceImage, errorImageName) {
        return new Promise((resolve) => {
            resemble(targetImage)
                .compareTo(referenceImage)
                .onComplete(function (data) {
                    if (data.misMatchPercentage <= 0.01) {
                        resolve(data);
                    }
                    else {
                        data.getDiffImage().pack().pipe(fs.createWriteStream(errorImageName));
                        resolve(data);
                    }
                });
        });
    }

    static createFolders() {
        let folderArray = [];
        folderArray.push("screenshots/diff/");
        folderArray.push("screenshots/reference/");
        folderArray.push("screenshots/screen/");

        folderArray.forEach((dir) => {
            if (!fs.existsSync(dir)) {
                shell.mkdir('-p', dir);
            }
        });
    }
}
module.exports = ImageProcessing;