NodeJS + WebPack setting client static data - node.js

I have a NodeJS/React/WebPack application that I'm trying to take environment variables that are present at build time and export them as variables that are available to the client without having to request them with AJAX.
What is currently setup is a /browser/index.js file with a method that is exported however the variables are not getting expanded when webpack runs.
function applicationSetup()
{
const config = JSON.parse(process.env.CONFIG);
const APPLICATION_ID = process.env.APPLICATION_ID;
.........
}
During the build process we run node node_modules/webpack/bin/webpack.js --mode production with npm.
What do I need to do in order to expand the environment variable to be their actual values when webpack creates the .js file?
Edit 8/23
I've tried adding it in the webpack.DefinePlugin section of the webpack.config.js file however it's still doesn't seem to be available in the client side code. What am I missing?
Edit #2 (webpack.config.js)
const getClientConfig = (env, mode) => {
return {
plugins: [
new webpack.DefinePlugin({
__isBrowser__: 'false',
__Config__: process.env.CONFIG,
__ApplicationID__:process.env.APPLICATION_ID
})]
}
module.exports = (env, options) => {
const configs = [
getClientConfig(options.env, options.mode)
];
return configs;
};

Related

Is there a way to use Vite with HMR and still generate the files in the /dist folder?

First of all, I wanna say that I've started using Vite awhile ago and I'm no Vite expert in any shape or form.
Now, about my problem: I'm working on a Chrome Extension which requires me to have the files generated in the /dist folder. That works excellent using vite build. But, if I try to use only vite (to get the benefits of HMR), no files get generated in the /dist folder. So I have no way to load the Chrome Extension.
If anyone has faced similar issues, or knows a config that I've overlooked, feel free to share it here.
Thanks!
With this small plugin you will get a build after each hot module reload event :
In a file hot-build.ts :
/**
* Custom Hot Reloading Plugin
* Start `vite build` on Hot Module Reload
*/
import { build } from 'vite'
export default function HotBuild() {
let bundling = false
const hmrBuild = async () => {
bundling = true
await build({'build': { outDir: './hot-dist'}}) // <--- you can give a custom config here or remove it to use default options
};
return {
name: 'hot-build',
enforce: "pre",
// HMR
handleHotUpdate({ file, server }) {
if (!bundling) {
console.log(`hot vite build starting...`)
hmrBuild()
.then(() => {
bundling = false
console.log(`hot vite build finished`)
})
}
return []
}
}
}
then in vite.config.js :
import HotBuild from './hot-build'
// vite config
{
plugins: [
HotBuild()
],
}

Dynamic import in NodeJS (in Gatsby): A dynamic import callback was not specified

I'm trying to use the dynamic imports in NodeJS, with a eS6 file, but can't get it work
I'm using it in a gatsby project within its gatsby-node.js file
exports.createPages = async props => {
//...
const name = './test'
;(async () => {
const data = await import(name)
console.log(data)
})()
Where test.js is just
export const hey = 'hi'
But I always get this A dynamic import callback was not specified.
Why is it not working? NodeJS version is 12.18.4
Update (11th of November 2022)
The syntax should be valid without importing any additional plugins with Babel.
If you need them or need to tweak/customize its configuration, please continue reading.
Since it's not currently a publish version, you need to install each desired module (babel-plugin-syntax-dynamic-import in your case) of ES6 and add it yo your babel configuration.
Run:
npm install --save-dev #babel/plugin-syntax-dynamic-import
Then, in your Babel file (babel.config.js or .babelrc in the root of your project) add it to plugins array:
"plugins": ["#babel/plugin-syntax-dynamic-import"]
Ideally, your Babel file should look like:
module.exports = function(api) {
api.cache(true);
const presets = [
[`#babel/preset-env`, { 'useBuiltIns': `usage`, 'corejs': `2` }],
[`#babel/preset-react`, { 'development': true, minify: true }],
];
const plugins = [
`#babel/plugin-syntax-dynamic-import`,
];
return { presets, plugins };
};

How to handle different .env files in Next?

What I want
I have created a new Next project, and I want to manage app behavior according to the NODE_ENV variable. The application must load different variables located in different .env files. eje. if I load NODE_ENV=development, the application should to load the variables located in .env.development file. What is the most efficient and safe way to do it in Next.
What I have
package.json
In the dev script I pass the environment type:
"scripts": {
"dev": "cross-env NODE_ENV=development next",
"build": "next build",
"start": "next start",
},
next.config.js
In the next configuration I load environment variables from correct .env file with dotenv library according to NODE_ENV variable pass in devscript in package.json.
const path = require('path');
const withOffline = require('next-offline');
const webpack = require('webpack');
require('dotenv').config({
path: path.resolve(
__dirname,
`.env.${process.env.NODE_ENV}`,
),
});
module.exports = withOffline({
webpack: (config) => {
// Returns environment variables as an object
const env = Object.keys(process.env).reduce((acc, curr) => {
acc[`process.env.${curr}`] = JSON.stringify(process.env[curr]);
return acc;
}, {});
// Allows you to create global constants which can be configured
// at compile time, which in our case is our environment variables
config.plugins.push(new webpack.DefinePlugin(env));
return config;
},
});
.env.development
TITLE=modo development
pages/index.js
function HomePage() {
return <div>{process.env.TITLE}</div>
}
export default HomePage
With this aproach...
This is the most efficient and safe way to handle diferent .env files in Next?
Nextjs supports env by default without the need to use of webpack.DefinePlugin, just pass it to the env property of next.config.js.
So your code will become:
// next.conf.js
const path = require('path');
const withOffline = require('next-offline');
const webpack = require('webpack');
require('dotenv').config({
path: path.resolve(
__dirname,
`.env.${process.env.NODE_ENV}`,
),
});
module.exports = withOffline({
env: {
VAR_1: process.env.VAR_1
...
// List all the variables that you want to expose to the client
}
});
PAY ATTENTION: these env variables may be exposed to the client side (if you use them in one of your app page).
For example, if your process.env is containing secrets, and by mistake you are using one of them in one of the pages / components that are used by pages, they will be inside js files that are downloaded to the client side.
Since Next.js 9.4, there is a built in .env loading functionality, read about it here https://nextjs.org/docs/basic-features/environment-variables
Agree with the #felixmosh that Nextjs supports env by default without the need to use of webpack.DefinePlugin, but...
It may be seen as limited and confused while loading different configurations on each environment. You can see common problem here
enter link description here
You can solve this problem easily by following these small steps.
You’ll need to create a folder config on the root, with all environment stages you’d like to have.
You can add the initial/common configuration in default.js like this.
API: {
API_URL: process.env.API_URL || '<http://localhost:4000>',
ENDPOINT: '********',
IS_MOCKING_ENABLED: false,
},
}```
Include above config files in the Next.config.js file by publicRuntimeConfig. If you’d like to have it just on the server-side use just serverRuntimeConfig like this.
const APIConfig = config.get('API')
const nextConfig = {
publicRuntimeConfig: {
APIConfig,
},
}
module.exports = nextConfig ```
Usage in any file.
const { publicRuntimeConfig } = getConfig()
const APIConfig = publicRuntimeConfig.APIConfig
[...] ```
Finally, in your package.json. You can inject the environment variables to load the appropriate configuration.
"start:local": "NODE_ENV=development run-p dev"
Reference: enter link description here for detail explanation.

Test process.env with Jest

I have an application that depends on environmental variables like:
const APP_PORT = process.env.APP_PORT || 8080;
And I would like to test that for example:
APP_PORT can be set by a Node.js environment variable.
or that an Express.js application is running on the port set with process.env.APP_PORT
How can I achieve this with Jest? Can I set these process.env variables before each test or should I mock it somehow maybe?
The way I did it can be found in this Stack Overflow question.
It is important to use resetModules before each test and then dynamically import the module inside the test:
describe('environmental variables', () => {
const OLD_ENV = process.env;
beforeEach(() => {
jest.resetModules() // Most important - it clears the cache
process.env = { ...OLD_ENV }; // Make a copy
});
afterAll(() => {
process.env = OLD_ENV; // Restore old environment
});
test('will receive process.env variables', () => {
// Set the variables
process.env.NODE_ENV = 'dev';
process.env.PROXY_PREFIX = '/new-prefix/';
process.env.API_URL = 'https://new-api.com/';
process.env.APP_PORT = '7080';
process.env.USE_PROXY = 'false';
const testedModule = require('../../config/env').default
// ... actual testing
});
});
If you look for a way to load environment values before running the Jest look for the answer below. You should use setupFiles for that.
Jest's setupFiles is the proper way to handle this, and you need not install dotenv, nor use an .env file at all, to make it work.
jest.config.js:
module.exports = {
setupFiles: ["<rootDir>/.jest/setEnvVars.js"]
};
.jest/setEnvVars.js:
process.env.MY_CUSTOM_TEST_ENV_VAR = 'foo'
That's it.
Another option is to add it to the jest.config.js file after the module.exports definition:
process.env = Object.assign(process.env, {
VAR_NAME: 'varValue',
VAR_NAME_2: 'varValue2'
});
This way it's not necessary to define the environment variables in each .spec file and they can be adjusted globally.
In ./package.json:
"jest": {
"setupFiles": [
"<rootDir>/jest/setEnvVars.js"
]
}
In ./jest/setEnvVars.js:
process.env.SOME_VAR = 'value';
You can use the setupFiles feature of the Jest configuration. As the documentation said that,
A list of paths to modules that run some code to configure or set up
the testing environment. Each setupFile will be run once per test
file. Since every test runs in its own environment, these scripts will
be executed in the testing environment immediately before executing
the test code itself.
npm install dotenv dotenv that uses to access environment variable.
Create your .env file to the root directory of your application and add this line into it:
#.env
APP_PORT=8080
Create your custom module file as its name being someModuleForTest.js and add this line into it:
// someModuleForTest.js
require("dotenv").config()
Update your jest.config.js file like this:
module.exports = {
setupFiles: ["./someModuleForTest"]
}
You can access an environment variable within all test blocks.
test("Some test name", () => {
expect(process.env.APP_PORT).toBe("8080")
})
Expanding a bit on Serhan C.'s answer...
According to the blog post How to Setup dotenv with Jest Testing - In-depth Explanation, you can include "dotenv/config" directly in setupFiles, without having to create and reference an external script that calls require("dotenv").config().
I.e., simply do
module.exports = {
setupFiles: ["dotenv/config"]
}
In test file:
const APP_PORT = process.env.APP_PORT || 8080;
In the test script of ./package.json:
"scripts": {
"test": "jest --setupFiles dotenv/config",
}
In ./env:
APP_PORT=8080
In my opinion, it's much cleaner and easier to understand if you extract the retrieval of environment variables into a utility (you probably want to include a check to fail fast if an environment variable is not set anyway), and then you can just mock the utility.
// util.js
exports.getEnv = (key) => {
const value = process.env[key];
if (value === undefined) {
throw new Error(`Missing required environment variable ${key}`);
}
return value;
};
// app.test.js
const util = require('./util');
jest.mock('./util');
util.getEnv.mockImplementation(key => `fake-${key}`);
test('test', () => {...});
Depending on how you can organize your code, another option can be to put the environment variable within a function that's executed at runtime.
In this file, the environment variable is set at import time and requires dynamic requires in order to test different environment variables (as described in this answer):
const env = process.env.MY_ENV_VAR;
const envMessage = () => `MY_ENV_VAR is set to ${env}!`;
export default myModule;
In this file, the environment variable is set at envMessage execution time, and you should be able to mutate process.env directly in your tests:
const envMessage = () => {
const env = process.env.MY_VAR;
return `MY_ENV_VAR is set to ${env}!`;
}
export default myModule;
Jest test:
const vals = [
'ONE',
'TWO',
'THREE',
];
vals.forEach((val) => {
it(`Returns the correct string for each ${val} value`, () => {
process.env.MY_VAR = val;
expect(envMessage()).toEqual(...
you can import this in your jest.config.js
require('dotenv').config()
this work for me
All the above methods work if you're using require("dotenv").config within the jest.config.js file, a NodeJS application without TypeScript such as what Jialx or Henry Tipantuna has suggested.
But if you're using ts-jest and within the jest.config.ts file.
import dotenv from "dotenv"
dotenv.config()
/* config options below */
When using Typescript the following works for me:
in root:
jest.config.js
/* eslint-disable #typescript-eslint/no-var-requires */
const { pathsToModuleNameMapper } = require('ts-jest');
const { compilerOptions } = require('./tsconfig.paths.json');
module.exports = {
// [...]
moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths, { prefix: '<rootDir>/' }),
};
process.env = Object.assign(process.env, {
env_name: 'dev',
another_var: 'abc123',
});
To build upon #HenryTipantuña's suggestion is to import dotenv in your jest.config.js and use a .env.test file in the config path
require('dotenv').config({
path: '.env.test'
})
Building on top of #jahller's answer.
I made it responsive so you don't need to keep the files in sync as things change.
Put this at the bottom of your jest.config.js file.
const arr = require('fs')
.readFileSync('.env', 'utf8')
.split('\n')
.reduce((vars, i) => {
const [variable, value] = i.split('=')
vars[variable] = value
return vars
}, {})
process.env = Object.assign(process.env, arr)
It reads the contents of your .env file, splits every new line and reduces it all back down to an object where you then assign it to process.env
OR
just use dotenv in jest.setup.js 🤷‍♂️
i have most simple for implementation env (specialy test.env)
require("dotenv").config({ path: './test.env' });
const { sum } = require('./sum.js');
describe('sum', () => {
beforeEach(() => {
jest.resetModules(); // remove cache
})
test('should success', () => {
expect(sum(1, 3)).toEqual(4);
})
})
I think you could try this too:
const currentEnv = process.env;
process.env = { ENV_NODE: 'whatever' };
// test code...
process.env = currentEnv;
This works for me and you don't need module things

Set NODE_ENV from Grunt task

I would like to set the NODE_ENV variable at the beginning of a Grunt task, to development or production, but it looks it's not as simple as I thought.
The reason, why I would like this is that I use grunt-webpack, which expects NODE_ENV to be set correctly to "development" or "production". But I also would like to initialize my tasks exclusively from grunt, if possible.
I created the following test Gruntfile, using the grunt-shell and cross-env modules:
function log(err, stdout, stderr, cb, e) {
if (err) {
cb(err);
return;
}
console.log(process.env.NODE_ENV);
console.log(stdout);
cb();
}
module.exports = function(grunt) {
grunt.initConfig({
shell: {
dev: {
command : 'cross-env NODE_ENV="development"',
options: {
callback: log
}
},
dist: {
command : 'cross-env NODE_ENV="production"',
options: {
callback: log
}
}
}
});
grunt.loadNpmTasks('grunt-shell');
};
Line 6 of log() should echo the actual value of process.env.NODE_ENV, but it constantly says undefined, even if I check it manually in the node console.
If I set it manually from the terminal, like set NODE_ENV=production (set is for Windows), everywhere echoes the value production, as I would like it to.
Your test won't work because grunt-shell runs a child_process and your callback runs after it ends and under the main process.
Same thing would happen with cross-env.
If you want to pass an environment variable to grunt-shell, you should use the options configuration according to the documentation.
For example:
grunt.initConfig({
shell: {
dev: {
command : 'echo %NODE_ENV%', //windows syntax
options: {
execOptions: {
env: {
'NODE_ENV': 'dev'
}
},
callback: log
}
}
}
});
This will still print undefined for process.env.NODE_ENV, but the value of NODE_ENV will be available in the stdout because of the echo.
On a side note, it sounds like you're trying to run a process (grunt-shell), which runs a process (cross-env), which runs a process (webpack or grunt-webpack).
Why not just use the cross-env example usage? It looks pretty close to what you need.
Or you can just define the variable in the task config itself and lose all of these wrappers.
LifeQuery's answer helped me a lot to find out what the problem actually was. I first realized that webpack.DefinePlugin() actually doesn't change anything on process.env.NODE_ENV (and it would be too late anyway, as it transforms code parsed by webpack after all loaders).
After this I created a solution, which does what I want. This is how my customized Gruntfile.js begins:
'use strict';
const path = require('path');
const webpack = require('webpack');
module.exports = function (grunt) {
// Setting the node environment based on the tasks's name or target
let set_NODE_ENV = function () {
const devTasks = ['webpack-dev-server', 'dev', 'hmr', 'watch'],
devTargets = [':dev'],
task = grunt.cli.tasks[0], // The name of the (first) task we initialized grunt with ('webpack-dev-server' if started 'grunt webpack-dev-server)
target = ':'+grunt.option('target'),
devEnv = (devTasks.indexOf(task) > -1 || devTargets.indexOf(target) > -1);
process.env.NODE_ENV = devEnv ? 'development' : 'production';
}();
const webpackConfig = require('../assets/webpack.config');
grunt.initConfig({
// ...usual Gruntfile content
});
};
I created a whitelist of grunt task names and targets when I set the process.env.NODE_ENV. As it is placed before the grunt.initConfig(), the configuration object can use process.env.NODE_ENV with the desired state.
It will set NODE_ENV to "development" if starting definitely webpack-dev-server, dev, hmr or watch tasks, or any other tasks with the :dev target.

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