ddo/node-resemble

const canvas = require('canvas');
const imageType = require('image-type');

function overrideWindow() {
    const doc = {};
    doc.createElement = function(tag) {
        return (tag !== 'canvas') ?
            false :
            new canvas;
    };
    return {
        document: doc
    }
}

function overrideFileReader() {
    const FileReader = function() {};
    FileReader.prototype.readAsDataURL = function(buffer) {
        this.onload({
            target: {
                result: 'data:image/' + imageType(buffer) + ';base64,' + buffer.toString('base64')
            }
        });
    };
    return FileReader;
}

function overrideImage() {
    const Image = canvas.Image;
    Image.prototype.setAttribute = function() {};
    return Image;
}

module.exports = function() {
    if (typeof window === "undefined") {
        global.window = overrideWindow()
    }
    if (typeof FileReader === "undefined") {
        global.FileReader = overrideFileReader()
    }
    if (typeof Image === "undefined") {
        global.Image = overrideImage()
    }
    const resemblejs = require('resemblejs');
    return resemblejs.apply(this, arguments);
};