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- /*
- MIT License http://www.opensource.org/licenses/mit-license.php
- Author Tobias Koppers @sokra
- */
- "use strict";
-
- /**
- * Gets the value at path of object
- * @param {object} obj object to query
- * @param {string} path query path
- * @returns {any} - if {@param path} requests element from array, then `undefined` will be returned
- */
- const getProperty = (obj, path) => {
- let name = path.split(".");
- for (let i = 0; i < name.length - 1; i++) {
- obj = obj[name[i]];
- if (typeof obj !== "object" || !obj || Array.isArray(obj)) return;
- }
- return obj[name.pop()];
- };
-
- /**
- * Sets the value at path of object. Stops execution, if {@param path} requests element from array to be set
- * @param {object} obj object to query
- * @param {string} path query path
- * @param {any} value value to be set
- * @returns {void}
- */
- const setProperty = (obj, path, value) => {
- let name = path.split(".");
- for (let i = 0; i < name.length - 1; i++) {
- if (typeof obj[name[i]] !== "object" && obj[name[i]] !== undefined) return;
- if (Array.isArray(obj[name[i]])) return;
- if (!obj[name[i]]) obj[name[i]] = {};
- obj = obj[name[i]];
- }
- obj[name.pop()] = value;
- };
-
- /**
- * @typedef {'call' | 'make' | 'append'} ConfigType
- */
- /**
- * @typedef {(options: object) => any} MakeConfigHandler
- */
- /**
- * @typedef {(value: any, options: object) => any} CallConfigHandler
- */
- /**
- * @typedef {any[]} AppendConfigValues
- */
-
- class OptionsDefaulter {
- constructor() {
- /**
- * Stores default options settings or functions for computing them
- */
- this.defaults = {};
- /**
- * Stores configuration for options
- * @type {{[key: string]: ConfigType}}
- */
- this.config = {};
- }
-
- /**
- * Enhancing {@param options} with default values
- * @param {object} options provided options
- * @returns {object} - enhanced options
- * @throws {Error} - will throw error, if configuration value is other then `undefined` or {@link ConfigType}
- */
- process(options) {
- options = Object.assign({}, options);
- for (let name in this.defaults) {
- switch (this.config[name]) {
- /**
- * If {@link ConfigType} doesn't specified and current value is `undefined`, then default value will be assigned
- */
- case undefined:
- if (getProperty(options, name) === undefined) {
- setProperty(options, name, this.defaults[name]);
- }
- break;
- /**
- * Assign result of {@link CallConfigHandler}
- */
- case "call":
- setProperty(
- options,
- name,
- this.defaults[name].call(this, getProperty(options, name), options)
- );
- break;
- /**
- * Assign result of {@link MakeConfigHandler}, if current value is `undefined`
- */
- case "make":
- if (getProperty(options, name) === undefined) {
- setProperty(options, name, this.defaults[name].call(this, options));
- }
- break;
- /**
- * Adding {@link AppendConfigValues} at the end of the current array
- */
- case "append": {
- let oldValue = getProperty(options, name);
- if (!Array.isArray(oldValue)) {
- oldValue = [];
- }
- oldValue.push(...this.defaults[name]);
- setProperty(options, name, oldValue);
- break;
- }
- default:
- throw new Error(
- "OptionsDefaulter cannot process " + this.config[name]
- );
- }
- }
- return options;
- }
-
- /**
- * Builds up default values
- * @param {string} name option path
- * @param {ConfigType | any} config if {@param def} is provided, then only {@link ConfigType} is allowed
- * @param {MakeConfigHandler | CallConfigHandler | AppendConfigValues} [def] defaults
- * @returns {void}
- */
- set(name, config, def) {
- if (def !== undefined) {
- this.defaults[name] = def;
- this.config[name] = config;
- } else {
- this.defaults[name] = config;
- delete this.config[name];
- }
- }
- }
-
- module.exports = OptionsDefaulter;
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