| import { YError } from '../yerror.js'; | |
| let previouslyVisitedConfigs = []; | |
| let shim; | |
| export function applyExtends(config, cwd, mergeExtends, _shim) { | |
| shim = _shim; | |
| let defaultConfig = {}; | |
| if (Object.prototype.hasOwnProperty.call(config, 'extends')) { | |
| if (typeof config.extends !== 'string') | |
| return defaultConfig; | |
| const isPath = /\.json|\..*rc$/.test(config.extends); | |
| let pathToDefault = null; | |
| if (!isPath) { | |
| try { | |
| pathToDefault = require.resolve(config.extends); | |
| } | |
| catch (_err) { | |
| return config; | |
| } | |
| } | |
| else { | |
| pathToDefault = getPathToDefaultConfig(cwd, config.extends); | |
| } | |
| checkForCircularExtends(pathToDefault); | |
| previouslyVisitedConfigs.push(pathToDefault); | |
| defaultConfig = isPath | |
| ? JSON.parse(shim.readFileSync(pathToDefault, 'utf8')) | |
| : require(config.extends); | |
| delete config.extends; | |
| defaultConfig = applyExtends(defaultConfig, shim.path.dirname(pathToDefault), mergeExtends, shim); | |
| } | |
| previouslyVisitedConfigs = []; | |
| return mergeExtends | |
| ? mergeDeep(defaultConfig, config) | |
| : Object.assign({}, defaultConfig, config); | |
| } | |
| function checkForCircularExtends(cfgPath) { | |
| if (previouslyVisitedConfigs.indexOf(cfgPath) > -1) { | |
| throw new YError(`Circular extended configurations: '${cfgPath}'.`); | |
| } | |
| } | |
| function getPathToDefaultConfig(cwd, pathToExtend) { | |
| return shim.path.resolve(cwd, pathToExtend); | |
| } | |
| function mergeDeep(config1, config2) { | |
| const target = {}; | |
| function isObject(obj) { | |
| return obj && typeof obj === 'object' && !Array.isArray(obj); | |
| } | |
| Object.assign(target, config1); | |
| for (const key of Object.keys(config2)) { | |
| if (isObject(config2[key]) && isObject(target[key])) { | |
| target[key] = mergeDeep(config1[key], config2[key]); | |
| } | |
| else { | |
| target[key] = config2[key]; | |
| } | |
| } | |
| return target; | |
| } | |