Webpack using wrong node_modules folder

Question

I have a vue client project that uses a vue library project (the vue library project is also using some 3rd party packages like vue-material).

They are linked via the client project's Package.json like this "lib": "file:../lib" and I am importing components in the client project using import Comp from "lib/src/components/Comp";

The problem is that when I build the client project using Webpack, the files in my library use lib/node_modules/vue instead of node_modules/vue which causes double vue instancing.

Anyone has any idea why when I am using webpack build from the client folder, it looks for vue package in my library folder? and is there a way to get around that?

My webpack.config

"use strict";
const path = require("path");
const utils = require("./utils");
const config = require("../config");
const vueLoaderConfig = require("./vue-loader.conf");

function resolve(dir) {
  return path.join(__dirname, "..", dir);
}

module.exports = {
  entry: {
    app: ["babel-polyfill", "./src/main.js"]
  },
  output: {
    path: config.build.assetsRoot,
    filename: "[name].js",
    publicPath: process.env.NODE_ENV === "production" ? config.build.assetsPublicPath : config.dev.assetsPublicPath
  },
  resolve: {
    extensions: [".js", ".vue", ".json"],
    alias: {
      vue$: "vue/dist/vue.esm.js",
      "@": resolve("src"),
      src: resolve("src"),
      assets: resolve("src/assets"),
      components: resolve("src/components"),
      utilities: resolve("src/utilities"),
      directives: resolve("src/directives"),
      plugins: resolve("src/plugins"),
      data: resolve("src/data"),
      "vuex-store": resolve("src/store"),
      "lib": resolve("node_modules/lib")
    }
  },
  module: {
    rules: [
      {
        test: /\.(js|vue)$/,
        loader: "eslint-loader",
        enforce: "pre",
        include: [resolve("src")],
        options: {
          formatter: require("eslint-friendly-formatter")
        }
      },
      {
        test: /\.vue$/,
        loader: "vue-loader",
        options: vueLoaderConfig
      },
      {
        test: /\.js$/,
        loader: "babel-loader",
        include: [resolve("src"), resolve("../lib/src")]
      },
      {
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        loader: "url-loader",
        options: {
          limit: 10000,
          name: utils.assetsPath("img/[name].[hash:7].[ext]")
        }
      },
      {
        test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
        loader: "url-loader",
        options: {
          limit: 10000,
          name: utils.assetsPath("media/[name].[hash:7].[ext]")
        }
      },
      {
        test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: "base64-font-loader",
        options: {
          limit: 10000,
          name: utils.assetsPath("fonts/[name].[hash:7].[ext]")
        }
      },
      {
        test: /\.ico$/,
        loader: "file-loader?name=[name].[ext]"
      }
    ]
  }
};

My client's main entry

// The Vue build version to load with the `import` command
// (runtime-only or standalone) has been set in webpack.base.conf with an alias.

// Core Imports
import Vue from 'vue'
import App from './App'

// Plugins
import { ComponentsPlugin } from "lib/src/components";

/* eslint-disable no-new */
new Vue({
  el: '#app',
  router,
  store,
  template: '<App/>',
  components: { App }
})

Answer 1

As I ran out of solutions to this problem I decided to debug webpack's compiler.

It seems webpack uses a library called 'enhanced-resolve' (We actually send parameters to that library in our webpack's resolve:{} section). And using the resolve.alias property we can redirect any require to any folder we want.

So to redirect any require("vue") to my own vue.esm.js, all I need is to add an entry like this (I originally had that line but it was pointing to a relative path rather than an absolute path):

resolve: {
  alias: {
    vue$: resolve("node_modules/vue/dist/vue.esm.js"),
  }
}

Note the $ at the end of the library name, It signals enhanced-resolve that the package only has 1 module so any require whos name is "vue" or a sub-directory of "vue" should be parsed using the alias.

Enhanced-Resolve - ResolverFactory.js

if(/\$$/.test(alias)) {
    onlyModule = true;
    ....
}

Enhanced-Resolve - AliasPlugin.js

// InnerRequest is the path (vue/dist/vue.esm.js)
// name is the alias name without the $ (vue)
if(innerRequest === name || (!onlyModule && startsWith(innerRequest, name + "/"))) {
    continue resolving....
}