I am making a npm package which will have a node executable file.
My src folder include an index.js and other helper files in helper folder.
I want to use ES6+ syntax.
I want to import those helper files in index.js.
Build everything and create a single file which will be my executable.
I tried just Babel to build and transpile my code to ES5 but it wont work on imports.
Executable using Webpack + Babel resulted in errors.
Please point me to resource / help which will help me solve this problem
Related
I am used to using NPM packages with Webpack, but I'm wondering how you're supposed to use NPM packages without Webpack.
I know how to install packages. I just don't know how to use them, since you can't just import modules in plain js.
Webpack compiles a bunch of javascript files and combines them into a single one for web distribution. NPM downloads javascript files through packages.
Here's some scenarios where you might use NPM without webpack
You are doing Node.js server-side javascript development. There's no webpack here
You are using a webpack alternative like rollup or browserify
You directly do anything else with the files npm downloads. Maybe you concatenate, throw them in a Makefile or maybe you expose node_modules directly to the world and reference their full paths directly.
Most of my web and server-side development is without webpack.
Why you can't import in plain js?
If you correctly define the package entry point like
"main": "dist/index.js",
"module": "dist/index.js",
Those files can be plain ES6 javascript with named exports or export default, and you can import them after intalling your package with regular import.
You don't need webpack nor babel to make an mpm module. Just put in any folder the files you want to distribute, specifying the main entry point and export elements on that file.
Now... in an angular or react application for example, they may install your component and will use babel and webpack to first transpile your component to ES5 with babel, and then bundle your code together with the rest of their app using webpack.
For front-end, not node.js but still NPM modules.
HTML can import directly ES6 modules but the file must be in .mjs format and provide export default, Module.exports in regular .js file wont't work. This is not a common thing and you'll run into problems if there are subdependencies that don't use ES6 modules. If you find a module that supports it. i.e. some-module
npm install some-module
And in the same directory next to node_modules create index.html pointing straight to the modular bundle
<h1>I'm HTML</h1>
<script type="module">
import SomeModule from './node_modules/some-module/bundle.mjs';
const mod = new SomeModule();
mod.doStuff();
</script>
Here's an article about this https://medium.com/passpill-project/files-with-mjs-extension-for-javascript-modules-ced195d7c84a
npm init
To create a package.json file
npm install --save <package>
To install a package and save it in the package.json file
So I have this problem where I have created a project using create-react-app. I have another project common-components which has webpack and a build process and has all the common and shareable components. what I did was I npm link common-components and then npm link common-components inside the Main project to make it avaible as node module. now the problem is when I try importing the ES6 React components It gives a transpile error. and I know this why it throws that. It doesnt transpiled by the babel-loader I am using in the Main project. I tried include this in the entry. But It still doesnt transpiled which It should. I donnot wanna build it to es5 and then import. I wanted to import it as it is and then build it with the Main project.
webpack: include : ['/mainPath', "/sharecomponentpath"]
I've created a React project with create-react-app command, it uses webpack.
In order to use SASS I needed to eject with npm run eject command and to manually add SCSS loader inside loaders array, as explained here.
This is my first time with React and I'm using a per comonent style approach which consist in importing a .scss file per component.
I have a global variables file in ~/my-project-folder/src/assets/styles/_variables.scss and I want to import it from ~/my-project-folder/src/scenes/Auth/Login/styles/login.scss, of course I don't want to do something like #import '../../../assets/styles/_variables.scss'.
I've seen that I can refer to SASS files inside node_modules folder this way: #import "~bootstrap-sass/assets/stylesheets/bootstrap/variables"; so I'm wondering what is the way to refer to my project's root directory, i.e. ~/my-project-folder.
When you do this #import "~bootstrap-sass/assets/stylesheets/bootstrap/variables"; it will look for the bootstrap-sass in node_modules but when you want to import your global sass file in your other files then you have to give the relative path otherwise webpack will not able to resolve it for your. You can try to give public path in your webpack
I have read several times the documentation provided at :
Node API Babel 6 Docs
I'm starting out learning pg-promise following the Learn by Example tutorial and would prefer to work with ES6 and transpile to ES5 with Babel but am unsure of a few things :
After installing babel-core, what preset do I use and where/how do I configure this to work?
The documentation was unclear to me about which file I put: require("babel-core").transform("code", options); into and what parts of that code are place holders. When I use that code, do I just use it one time somewhere and then I can use ES6 in every other file? How would this be achieved?
I read about this .babelrc file and would like to confirm if the actual filename is ".babelrc" or if that is just the file extension and where in relation to the root directory of my project do I put that file.. and how do I link to it?
If I'm using pg-promise should I be using ES6 and Babel or will running : npm install as described under the Testing section for pg-promise be enough and trying to use ES6 with this create more problems?
I was hoping to take advantage of let and const if the need came up during my server side development.
Is there a standard file structure for a node+babel+pg-promise server setup?
Edit
Worth noting that I have also read Node JS with Babel-Node and saw that using this should be avoided. The final answer at the very bottom didn't really make sense to me for similar reasons I'm having trouble following the actual documentation provided by Babel.
1.a What Preset is needed?
You will need to install Babel firstly with npm install babel-core --save-dev in the root directory of your project using a Terminal window like Command Prompt.
Once installed, you will need to install the es2015 preset with npm install babel-preset-es2015 --save-dev. Babel-Core is Promises/A+ Compliant but not ideal for usage due to poor error handling so a library such as Bluebird should be used instead for this purpose. In order to transpile, babel-core will still need to be installed and es2015 enables ES6->ES5 transpiling so you can use fancy things like let and const etc.
1.b Where to put require("babel-core");?
instead, use require("babel-core/register"); and place it inside your Entry file typically called, "server.js". The server.js file will need to use CommonJS (ES5) exclusively.
By using the "require" statement it will apply all relevant transforms to all code being required into the Entry file and all files being required/included into those files.
You point to the Entry file inside package.json under the "main": section.
Package.json is created when you initialise the project with npm init at the root directory of your project inside the Terminal Window
One approach to this would be :
Entry File - server.js
server.js - requires {babel-core and the main ES6 file : config.js/jsx/es6/es}
config.es6 - uses ES6 and has includes(requires) for all other project files that can also use ES6 as they get transpiled by being loaded into the "config" file which is being directly transpiled by babel-core.
2. What is .babelrc?
.babelrc is the filename and should be placed in the same folder as your package.json file (normally the root directory) and will automatically "load" when babel-core is required to determine which preset(s) or plugins are to be used.
Inside .babelrc , you will need to add the following code :
{
"presets": ["es2015"]
}
3. pg-promise Testing Section
A direct quote from the developer recently answered this
You do not need to worry about steps in the Tests, use only the steps in the install. The one in tests relates to the dev dependency installation, in order to run tests. The pg-promise can work with any promise library compliant with Promises/A+ spec.
4. Standard File/Folder Structure for Server Side Projects?
There is no standard way to achieve this task as each project has unique demands. A good starting point would be to place the Entry file in the project root directory, the ES6 Config file in a "scripts" or "src" sub-folder and individual components in folders below that.
e.g.
ROOT/server.js
ROOT/src/config.es6
ROOT/src/component1/files.es6
ROOT/src/component2/files.es6
With this in place, Babel will successfully transpile all ES6 to ES5 and enable support of A+ compliant promises.
To begin using the node.js webserver This Guide provides a bit more insight and in the context of this answer the code shown would be placed into the ES6 config.es6 file and the following code would go into the Entry server.js file :
require("babel-core/register");
require("./src/config.es6");
The process for building Isomorphic web applications is different to this and would likely use things like grunt, gulp, webpack, babel-loader etc another example of which can be Found Here.
This answer is the combination of several key points provided by other answers to this question as well as contributions from experienced developers and my own personal research and testing. Thank you to all who assisted in the production of this answer.
This answer uses this simple directory structure
project/server/src/index.js => your server file
project/server/dist/ => where babel will put your transpiled file
Install babel dependencies
npm install -g babel nodemon
npm install --save-dev babel-core babel-preset-es2015
Add these npm scripts to your package.json file
"scripts": {
"compile": "babel server/src --out-dir server/dist",
"server": "nodemon server/dist/index.js
}
Create a .babelrc file in your project root directory
{
"presets": "es2015"
}
Transpile your directory with
npm run compile
Run your server with
npm run server
I think you should use a tool like grunt or gulp to manage all your "build" tasks. It will automate it for you, and you won't make errors.
In one command, you can transpile your code into babel ES2015 et start your application.
I suggest you to take a look at this simple project. (just install node_modules and launch npm start to start the app.js file)
However, if you really want to use babel manually,
.babelrc is the name of the file, you can see one in this project (redux) to have an example
.babelrc is a config file, if you want to see how it works, you can check this package.json (always redux)
There's actually no standard way that I know. You can use the project skeleton below if needed, and send pull request to improve it :-)
#makeitsimple
Step: 1
npm install nodemon --save
In project directory
Step: 2
yarn add babel-cli
yarn add babel-preset-es2015
Step: 2
In package.json-> scipts change 'start' to the following
start: "nodemon src/server.js --exec babel-node --presets es2015"
Step: 3
yarn start
I'm trying to use karma-commonjs, but I can't seem to get it to lookup packages properly. You can see that on this line, modules are looked up under ./node_modules if there's no config pragma for it in your karma.conf.js.
I can clearly tell that my package is under ./node_modules. Does karma's file server not serve from that directory? How should browser-oriented test code with Karma include an npm module? Any help with this would be tremendous.