forked from zhurui/management
86 lines
2.9 KiB
JavaScript
86 lines
2.9 KiB
JavaScript
|
/**
|
||
|
|
* @fileoverview Implements the Node.js require.resolve algorithm
|
||
|
|
* @author Nicholas C. Zakas
|
||
|
|
*/
|
||
|
|
|
||
|
|
"use strict";
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Requirements
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
const Module = require("module");
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Private
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
const DEFAULT_OPTIONS = {
|
||
|
|
|
||
|
|
/*
|
||
|
|
* module.paths is an array of paths to search for resolving things relative
|
||
|
|
* to this file. Module.globalPaths contains all of the special Node.js
|
||
|
|
* directories that can also be searched for modules.
|
||
|
|
*
|
||
|
|
* Need to check for existence of module.paths because Jest seems not to
|
||
|
|
* include it. See https://github.com/eslint/eslint/issues/5791.
|
||
|
|
*/
|
||
|
|
lookupPaths: module.paths ? module.paths.concat(Module.globalPaths) : Module.globalPaths.concat()
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Resolves modules based on a set of options.
|
||
|
|
*/
|
||
|
|
class ModuleResolver {
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Resolves modules based on a set of options.
|
||
|
|
* @param {Object} options The options for resolving modules.
|
||
|
|
* @param {string[]} options.lookupPaths An array of paths to include in the
|
||
|
|
* lookup with the highest priority paths coming first.
|
||
|
|
*/
|
||
|
|
constructor(options) {
|
||
|
|
this.options = Object.assign({}, DEFAULT_OPTIONS, options || {});
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Resolves the file location of a given module relative to the configured
|
||
|
|
* lookup paths.
|
||
|
|
* @param {string} name The module name to resolve.
|
||
|
|
* @param {string} extraLookupPath An extra path to look into for the module.
|
||
|
|
* This path is used with the highest priority.
|
||
|
|
* @returns {string} The resolved file path for the module.
|
||
|
|
* @throws {Error} If the module cannot be resolved.
|
||
|
|
*/
|
||
|
|
resolve(name, extraLookupPath) {
|
||
|
|
|
||
|
|
/*
|
||
|
|
* First, clone the lookup paths so we're not messing things up for
|
||
|
|
* subsequent calls to this function. Then, move the extraLookupPath to the
|
||
|
|
* top of the lookup paths list so it will be searched first.
|
||
|
|
*/
|
||
|
|
const lookupPaths = this.options.lookupPaths.concat();
|
||
|
|
|
||
|
|
lookupPaths.unshift(extraLookupPath);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Module._findPath is an internal method to Node.js, then one they use to
|
||
|
|
* lookup file paths when require() is called. So, we are hooking into the
|
||
|
|
* exact same logic that Node.js uses.
|
||
|
|
*/
|
||
|
|
const result = Module._findPath(name, lookupPaths); // eslint-disable-line no-underscore-dangle
|
||
|
|
|
||
|
|
if (!result) {
|
||
|
|
throw new Error(`Cannot find module '${name}'`);
|
||
|
|
}
|
||
|
|
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Public API
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
module.exports = ModuleResolver;
|