@cake-hub/cake-screenshot_diffs/src/backstop-configuration.js

A CAKE Screenshot diffing tool that includes a setup to comapre two given resources by screenshots taken from the available pages.

const deepMerge = require ("deepmerge");
const path = require ("path");

class BackstopConfiguration {

    static preparePath (configValue, defaultValue) {
        configValue = configValue || defaultValue;
        if (path.isAbsolute (configValue)) {
            return configValue;
        }
        return path.resolve (process.cwd (), configValue);
    }

    get ABSOLUTE_REPORT_PATH () {
        return BackstopConfiguration.preparePath (this._configuration.reportPath, "./backstop_report");
    }

    get REPORT_PATH () {
        let reportPath = this.ABSOLUTE_REPORT_PATH;
        reportPath = path.relative (path.resolve (__dirname, "../"), reportPath);
        return reportPath;
    }

    get DEFAULT_CONFIGURATION () {
        return {
            id: "cake_showroom",
            paths: {
                bitmaps_test: path.join (this.REPORT_PATH, "/bitmaps_test"),
                bitmaps_reference: path.join (this.REPORT_PATH, "/bitmaps_reference"),
                engine_scripts: path.relative (path.resolve (this.ABSOLUTE_REPORT_PATH, "../"), path.resolve (__dirname, "./engine_scripts")),
                html_report: path.join (this.REPORT_PATH, "/html_report"),
            },
            report: [
                "browser"
            ],
            engine: "puppeteer",
            onReadyScript: "on-ready-script.js",
            asyncCaptureLimit: 10,
            asyncCompareLimit: 50,
            debug: false,
            debugWindow: false,
        };
    }

    constructor (configuration = {}) {
        this._configuration = configuration;
    }

    _keyList (keyPath) {
        return keyPath.split (".");
    }

    update (object) {
        this._configuration = deepMerge (
            this._configuration, 
            object
        );
    }

    updateKey (keyPath, value) {
        let schema = this._configuration;  // a moving reference to internal objects within obj
        const pList = this._keyList (keyPath);
        const len = pList.length;

        // ensure the deepest object exists
        for(let i = 0; i < len - 1; i++) {
            const elem = pList [i];
            if(!schema [elem]) {
                schema [elem] = {};
            }
            schema = schema [elem];
        }

        schema [pList [len - 1]] = value;
    }

    removeKey (keyPath) {
        this.updateKey (keyPath, undefined);
    }

    getKey (keyPath) {
        let value = this._configuration;
        for (const key of this._keyList (keyPath)) {
            if (typeof value [key] === undefined) {
                return null;
            }
            value = value [key];
        }
        return value;
    }

    getConfiguration () {
        return deepMerge (
            this.DEFAULT_CONFIGURATION, 
            this._configuration
        );
    }

}

module.exports = BackstopConfiguration;