Webpack gives eslint errors while using npm link - javascript

I have a multi-package project set up, where I have one JavaScript package that relies on a TypeScript library. Initially I installed Sinopia and was reinstalling the library every time I made changes to it. Then I saw npm link and thought that it would be easier for development. Unfortunately, when I linked the library (using npm link ../typescript-package) and built, it gives an error:
ERROR in ../typescript-package/dist/index.js
Module build failed: Error: No ESLint configuration found.
Since they are separate packages, I'm not quite sure why Webpack is trying to apply eslint to this package. Here is my webpack.common.js file (using merge and the dev vs prod configs shouldn't matter):
// webpack.common.js
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const babelOptions = {
presets: ['react', 'es2015', 'stage-0'],
sourceMaps: true,
retainLines: true,
};
module.exports = {
entry: {
solver: './source/index.jsx',
},
output: {
path: `${__dirname}/dist`,
filename: '[name].js',
publicPath: '/dist/',
},
resolve: {
modules: ['source', 'node_modules/'],
extensions: ['.js', '.jsx', '/index.jsx', '.json', '.ts', '/index.ts', '.scss', '/index.scss', '.css'],
},
module: {
rules: [
{
test: /\.jsx?$/,
use: [
{
loader: 'babel-loader',
options: babelOptions,
},
{
loader: 'eslint-loader',
options: {
emitWarnings: true,
},
},
],
exclude: /node_modules/,
}, {
test: /\.js$/,
loader: 'source-map-loader',
enforce: 'pre',
exclude: /node_modules/,
}, {
test: /\.scss$/,
use: ExtractTextPlugin.extract({
fallback: 'style-loader',
use: [{
loader: 'css-loader',
options: {
minimize: true,
localIdentName: '[local]_[hash:base64:5]',
},
}, {
loader: 'sass-loader',
options: {
includePaths: ['source/design'],
},
}],
}),
},
],
},
plugins: [
new ExtractTextPlugin({
filename: '[name].css',
allChunks: true,
}),
],
node: {
global: true,
},
};
I can also provide other config or package.json files if need be.

Way 1 - Webpack recommendation
According to webpack doc : https://webpack.js.org/configuration/module/#rule-conditions
Be careful! The resource is the resolved path of the file, which means symlinked resources are the real path not the symlink location. This is good to remember when using tools that symlink packages (like npm link), common conditions like /node_modules/ may inadvertently miss symlinked files. Note that you can turn off symlink resolving (so that resources are resolved to the symlink path) via resolve.symlinks.
So according to it you can disable symlink : https://webpack.js.org/configuration/resolve/#resolvesymlinks
Way 2 - Fancy hack
But maybe you need symlinks for your project. So, I use my eslint rule like this :
{
test: /\.js$/,
enforce: 'pre',
use: 'eslint-loader',
include: path.resolve(__dirname), // <-- This tell to eslint to look only in your project folder
exclude: /node_modules/
}
Plus obviously your own config of this loader.

I was dealing with this, as well. I'm not exactly sure why ESLint is looking for the config file in the external package (I would expect the local rc file to be adequate) but the symlink created by npm link takes the external package out of ./node_modules/, which otherwise would have been excluded by the loader.
The fix I've come up with is to copy the package into ./node_modules/. It then gets filtered out through the excludes rule in your Webpack config.
I know this is incredibly inelegant, and shouldn't be "good enough", but I've spent some time trying to get around this issue, and this is the best I was able to come up with. Until something better comes along, you can at least get moving on more pressing issues.

You can also add a .eslintignore file and add the real path to the linked module
// Content of .eslintignore
C:/path/to/your/linked/module
This is needed, because webpack resolves the module by its real path and not by the path in the node_modules folder (see webpack docs). Usually eslint ignores node_modules by default, but because of that it does not work here.

Related

Is there a webpack loader / NPM script that compiles solely my SCSS files, similar to how Gulp works?

I've been using Webpack and have found it great for bundling, polyfilling and all sorts of other functions for Javascript, however I wondered if there was a known loader / NPM script that automatically compiles designated .scss files into one.
I have previously used the sass-loader, extract-css plugin to take SCSS out of components and bundle them into the final dist file which is fine for web apps. However, a lot of my day to day work is spent working on traditional websites, so it's often not generated via components / modules.
What I'm looking for, is anytime I save an .scss file, if this is included within my entry points / rules, it automatically compiles all .scss files into a dist/styles.css sheet.
I've had a look online and Gulp seems to offer this, but it looks like Webpack already does 90% of what Gulp offers so ideally would want to keep this all in Webpack.
Thanks in advance
import the scss file on your entry point like this import './style.scss';.
Install mini-css-extract-plugin.
Then add this to your webpack config
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module: {
rules: [
{
test: /\.(sc|c)ss$/,
use: [
// { loader: 'style-loader' },
{
loader: MiniCssExtractPlugin.loader, // extract css to a single file
options: {
publicPath: '../',
hmr: false
}
},
{
loader: 'css-loader', options: {
sourceMap: false
}
},
{
loader: 'postcss-loader',
options: {
sourceMap: false,
plugins: [
require('autoprefixer')
]
}
},
{
loader: 'sass-loader', options: { sourceMap: false }
}
],
exclude: /node_modules/
}
],
},

Why is my webpack babel setup emitting ESM requires when I have configured my preset to commonjs?

Today I observed babel/babel-loader exhibiting some undesirable behavior. I am bundling some assets for usage on nodejs. Post-compile, a bundle is generated with references to #babel/runtime/**/esm/**. Of course, node cannot import such files, and on node bundle.js I get:
Must use import to load ES Module: /my/project/node_modules/#babel/runtime/helpers/esm/defineProperty.js
require() of ES modules is not supported.
Right. Makes sense. But babel-loader injected those imports. In fact, the parent folder in #babel/runtime has all of the non-ESM things, which I actually probably do want imported! My babel config looks as such:
{
presets: [
[
"#babel/preset-env",
{
modules: 'commonjs',
targets: {
node: "current",
esmodules: false,
},
},
],
"#babel/preset-typescript",
]
}
As you can see, I'm attempting to tell babel via targets.esmodules: false and modules: 'commonjs' to use commonjs. I hoped these entries would tell babel to not expect ESM compatibility! None the less, generated bundles still look like:
...
var _toConsumableArray2 = _interopRequireDefault(__webpack_require__(/*! #babel/runtime/helpers/esm/toConsumableArray */ "#babel/runtime/helpers/esm/toConsumableArray"));
My full webpack config is pretty terse as well:
{
entry: serverFilename,
mode: 'development',
output: {
path: path.dirname(serverBuildFilename),
filename: path.basename(serverBuildFilename)
},
target: "node",
externals: [webpackNodeExternals()],
optimization: {
moduleIds: 'named',
minimize: false
},
resolve: {
extensions: ['.ts', '.tsx', '.wasm', '.mjs', '.js', '.json'],
},
module: {
rules: [
{
test: /\.tsx?$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader',
options: {
presets: babelConfig.presets // see babel config above
}
}
},
],
},
}
I can't tell if I'm missing configuration, if babel isn't respecting my configuration, or <your ideas here>!
All tips appreciated. Thanks!
It took me a while to figure out the solution and this post helps
https://github.com/webpack/webpack/issues/11696
Copied my solution from the issue here:
I ended up using webpack-node-externals in webpack config to sort of bypass this issue
const nodeExternals = require('webpack-node-externals');
// add these to the webpack config.
externals: [
nodeExternals({
whitelist: [/^#babel\/runtime/],
}),
],
This solution creates duplicated babel/runtime file injections and can also be mitigated by https://webpack.js.org/loaders/babel-loader/#babel-is-injecting-helpers-into-each-file-and-bloating-my-code

BabelJS is processing the wrong files when working with Webpack 4

I started from a configuration consisting of both webpack 3 and a similarly old babel version. It can be found in the following repo:
https://github.com/konradmi/react-loadable-ssr-code-splitting
I updated both webpack and babel to their latest versions, as well as all the node modules, and migrated the old configuration accordingly. This issue could stem from any of these.
Once I finished migrating, I noticed all the babel plugins traverse my webpack configs files (which are in a separate nested folder) instead of the actual js source files which are properly processed by webpack. (I verified it by doing some logging inside of the babel plugins).
The result is the same regardless of whether I'm using .babelrc or not.
The webpack config files used to be at the root of the project as you can see in the repo I linked to above, and now they are inside of a nested "config" folder.
At first I thought it might be the cause of this issue, so I tried the following:
Using path.resolve() in the entry point in order to use an absolute path to make sure it wouldn't possibly be re-interpreted by babel from a string relative to who knows where.
Putting the webpack config files back in the root of the project and building from that path.
In all the variations I've tried - webpack always does its job perfectly, while babel is traversing the wrong files. I'm not even sure how it's possible, babel-loader should be traversing the files which it got from the previous webpack rule, which emitted the correct files.
Here's my current Webpack 4 config files concatenated into 1 file and stripped of irrelevant rules and plugins for your convenience:
const webpack = require('webpack')
const path = require('path')
const webpackNodeExternals = require('webpack-node-externals')
module.exports = {
name: 'server',
target: 'node',
externals: [webpackNodeExternals()],
entry: './src/server.tsx',
output: {
filename: 'bundle.js',
chunkFilename: '[name].js',
path: path.resolve(__dirname, '../build')
},
mode: 'development',
stats: 'verbose',
resolve: {
extensions: ['.ts', '.tsx', '.js', '.jsx']
},
module: {
rules: [
{
test: /\.jsx?$/,
exclude: /node_modules/,
use: [
{
loader: 'babel-loader',
options: {
babelrc: false,
presets: [
[
'#babel/env',
{
'targets': {
'browsers': ['last 2 versions']
},
'debug': false
}
],
'#babel/preset-react'
],
plugins: [
'#babel/plugin-syntax-dynamic-import',
'#babel/plugin-proposal-class-properties',
'#babel/plugin-transform-object-assign',
'react-loadable/babel'
]
}
}
]
},
{
test: /\.tsx?$/,
exclude: /node_modules/,
use: [
{
loader: 'ts-loader'
}
]
}
]
}
}
I was importing webpack in my server source code, the files babel was going over were webpack imports which I added there in the source code. It couldn't find anything else other than those imports because due to previous rules webpack was exporting a bundle with evals containing the processed code (dev mode settings). The babel plugin wasn't looking for eval statements, so the only thing I could see was the processing of webpack related imports.

How to use compile ES6 (react) components and foundation sass with npm start

I followed this tutorial to setup a react project and I thought I nailed it. After installing everything works as it should.
But I have to create a website that uses foundation as a front-end lib. The tutorial I linked above runs server.js when I run npm start but foundation-cli uses the same command for compiling all foundation sass code to css.
At the moment when I run npm start it only runs react and not foundation. How can I run foundation too? can I make it so that it'll automatically run both?
Since you are already using Webpack, I would suggest you to use one of the loaders for it and compile your CSS with it. This one seems like it can do that for you.
This is not tested, but I assume you can add it to your Webpack config like this:
// be sure to install it with
// npm install sass-loader node-sass --save-dev
const path = require('path');
module.exports = {
context: path.join(__dirname, 'src'),
entry: [
'./main.js',
],
output: {
path: path.join(__dirname, 'www'),
filename: 'bundle.js',
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: [
'babel-loader',
],
},
{
test: /\.scss$/,
use: [{
loader: "style-loader" // creates style nodes from JS strings
}, {
loader: "css-loader" // translates CSS into CommonJS
}, {
loader: "sass-loader" // compiles Sass to CSS
}
}
],
},
resolve: {
modules: [
path.join(__dirname, 'node_modules'),
],
},
};

Webpack minification -p errors

I'm testing my production javascript with minifcation using webpack. It works fine unminified but when i add the -p flag:
NODE_ENV=production ./node_modules/webpack/bin/webpack.js -p --progress --colors
I get warnings and there are javascript errors. Appears it's removing things it shouldn't. Can't figure out why.
Warnings:
WARNING in client.js from UglifyJs
Side effects in initialization of unused variable React [./~/fluxible/lib/Fluxible.js:12,0]
Dropping unused function $$$enumerator$$makeSettledResult [./~/fluxible/~/es6-promise/dist/es6-promise.js:361,0]
Side effects in initialization of unused variable $$utils$$now [./~/fluxible/~/es6-promise/dist/es6-promise.js:35,0]
Side effects in initialization of unused variable $$utils$$o_create [./~/fluxible/~/es6-promise/dist/es6-promise.js:38,0]
Dropping unused variable internals [./~/react-router/~/qs/lib/utils.js:6,0]
Dropping side-effect-free statement [./~/fluxible/addons/provideContext.js:6,0]
Side effects in initialization of unused variable Action [./~/fluxible/~/dispatchr/lib/Dispatcher.js:7,0]
Dropping unused variable internals [./~/react-router/~/qs/lib/index.js:9,0]
Here's my webpack.config.js
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var path = require('path');
module.exports = {
entry: [
'./client.js',
],
output: {
path: path.join(__dirname, 'assets'),
filename: 'client.js',
publicPath: '/assets',
},
plugins: [
new ExtractTextPlugin('styles.css'),
],
module: {
loaders: [
{ test: /\.(js|jsx)$/, exclude: /node_modules\/(?!react-router)/, loader: 'react-hot!babel-loader?stage=0' },
{
test: /\.scss$/,
loader: ExtractTextPlugin.extract(
// activate source maps via loader query
'css?sourceMap!' +
'sass?sourceMap'
)
},
// bootstrap
{
test: /\.(ttf|eot|svg)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'url-loader?limit=10000&mimetype=application/font-eot',
},
{
test: /\.(woff)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'url-loader?limit=10000&mimetype=application/font-woff',
},
{
test: /\.(woff2)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'url-loader?limit=10000&mimetype=application/font-woff2',
},
{ test: /\.js$/, include: /node_modules\/bootstrap/, loader: 'imports?jQuery=jquery' },
],
},
};
Thanks
The warnings you see are due to the fact that the loader is parsing your node_module dependencies. Since the only you have excluded is whatever matches /node_modules/(?!react-router)/
Instead of using the exclude option for module loaders, try only white listing the modules you want to load with include
exclude should be used to exclude exceptions
try to prefer include when possible to match the directories

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