sync.js (2209B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var resolve = require( 'path' ).resolve; 24 var isString = require( '@stdlib/assert/is-string' ).isPrimitive; 25 var cwd = require( '@stdlib/process/cwd' ); 26 var exists = require( './../../exists' ).sync; 27 var validate = require( './validate.js' ); 28 29 30 // MAIN // 31 32 /** 33 * Synchronously resolves a path by walking parent directories. 34 * 35 * @param {string} path - path to resolve 36 * @param {Options} [options] - function options 37 * @param {string} [options.dir] - base directory 38 * @throws {TypeError} first argument must be a string 39 * @throws {TypeError} options argument must be an object 40 * @throws {TypeError} must provide valid options 41 * @returns {(string|null)} resolved path or null 42 * 43 * @example 44 * var path = resolveParentPath( 'package.json' ); 45 */ 46 function resolveParentPath( path, options ) { 47 var spath; 48 var child; 49 var opts; 50 var dir; 51 var err; 52 if ( !isString( path ) ) { 53 throw new TypeError( 'invalid argument. First argument must be a string primitive. Value: `' + path + '`.' ); 54 } 55 opts = {}; 56 if ( arguments.length > 1 ) { 57 err = validate( opts, options ); 58 if ( err ) { 59 throw err; 60 } 61 } 62 if ( opts.dir ) { 63 dir = resolve( cwd(), opts.dir ); 64 } else { 65 dir = cwd(); 66 } 67 // Start at a base directory and continue moving up through each parent directory until able to resolve a search path or until reaching the root directory... 68 while ( child !== dir ) { 69 spath = resolve( dir, path ); 70 if ( exists( spath ) ) { 71 return spath; 72 } 73 child = dir; 74 dir = resolve( dir, '..' ); 75 } 76 return null; 77 } 78 79 80 // EXPORTS // 81 82 module.exports = resolveParentPath;