标签：directory com 没有 core file nod modules stop github
阮一峰一则教程中， 将应用放置在 npm 模块安装目录同等级的目录（https://github.com/ruanyf/webpack-demos）下。
但是应用目录文件中， 引用标准库的使用方法没有变化
https://github.com/ruanyf/webpack-demos/blob/master/demo15/index.js
如下代码
import React from ‘react‘; import { render } from ‘react-dom‘; import { BrowserRouter, Switch, Route, Link } from ‘react-router-dom‘;
NodeJS的寻址规则是怎么样的呢？
尽管这个是前端的代码， 但是我们知道实际上引用模块，并打包的动作， 是交给 webpack来的做得。
但是模块的寻址规则， 则是哪找NodeJS的文件寻址规则， 没有改变，而是打包后， 变成前端可执行的集成代码。
https://nodejs.org/api/modules.html#modules_accessing_the_main_module
require(X) from module at path Y 1. If X is a core module, a. return the core module b. STOP 2. If X begins with ‘/‘ a. set Y to be the filesystem root 3. If X begins with ‘./‘ or ‘/‘ or ‘../‘ a. LOAD_AS_FILE(Y + X) b. LOAD_AS_DIRECTORY(Y + X) 4. LOAD_NODE_MODULES(X, dirname(Y)) 5. THROW "not found" LOAD_AS_FILE(X) 1. If X is a file, load X as JavaScript text. STOP 2. If X.js is a file, load X.js as JavaScript text. STOP 3. If X.json is a file, parse X.json to a JavaScript Object. STOP 4. If X.node is a file, load X.node as binary addon. STOP LOAD_INDEX(X) 1. If X/index.js is a file, load X/index.js as JavaScript text. STOP 2. If X/index.json is a file, parse X/index.json to a JavaScript object. STOP 3. If X/index.node is a file, load X/index.node as binary addon. STOP LOAD_AS_DIRECTORY(X) 1. If X/package.json is a file, a. Parse X/package.json, and look for "main" field. b. let M = X + (json main field) c. LOAD_AS_FILE(M) d. LOAD_INDEX(M) 2. LOAD_INDEX(X) LOAD_NODE_MODULES(X, START) 1. let DIRS = NODE_MODULES_PATHS(START) 2. for each DIR in DIRS: a. LOAD_AS_FILE(DIR/X) b. LOAD_AS_DIRECTORY(DIR/X) NODE_MODULES_PATHS(START) 1. let PARTS = path split(START) 2. let I = count of PARTS - 1 3. let DIRS = [GLOBAL_FOLDERS] 4. while I >= 0, a. if PARTS[I] = "node_modules" CONTINUE b. DIR = path join(PARTS[0 .. I] + "node_modules") c. DIRS = DIRS + DIR d. let I = I - 1 5. return DIRS
标签：directory com 没有 core file nod modules stop github
原文地址：https://www.cnblogs.com/lightsong/p/10540419.html
