webpack/lib/OptionsDefaulter.js

142 lines
3.7 KiB
JavaScript

/*
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;