babel.config.js use case
In Babel#next Website, I see if I want to compile node_modules, I should use babel.config.js not .babelrc to config babel.
And I have a try, If I using .babelrc with the latest babel#7.x, I can't compile node_modules to ES5 even I include node_modules in webpack config file, So, I'm confused why so design. The documention have no more explain.
Because they changed on babel#next so people can do conditions with processd.env.NODE_ENV. Just because of that. You won't be able to use .babelrc
Related
Starting with an empty directory, is it possible to do that? Should I use stage-0 like it is on the Babel REPL?
I hope to transpile it just like how ReactJS does it. For some reason, I always got an error for just a file containing:
let obj = { a: 1 };
let newObj = {
...obj,
ha: 3
};
Other times, I can transpile a file, but if I transpile a folder, it'd say:
foo.js: Cannot read property 'contexts' of null
The commands I tried included:
npx babel src --out-dir compiled --presets=es2015,react,minify --watch
but the errors I mentioned above appeared. Also, when I do
npm install babel-minify
it reported
found 2489 vulnerabilities (849 low, 306 moderate, 1329 high, 5 critical)
There is also a notice
As of v7.0.0-beta.55, we've removed Babel's Stage presets.
Please consider reading our blog post on this decision at
https://babeljs.io/blog/2018/07/27/removing-babels-stage-presets
for more details. TL;DR is that it's more beneficial in the
long run to explicitly add which proposals to use.
and I wonder what should be done.
Is it possible to
just continuously minify a folder
transpile some ES6 or ES7, 8 syntax that are not yet commonly supported
transpile JSX as well
?
I have found some reliable ways to make it work, although I am not sure when I should use babel.config.json and when to use .babelrc.json or .babelrc. It seems I have to run babel as ./node_modules/.bin/babel and is it true if I don't npm install babel using the -g option.
Here is what works:
create a folder, such as TryBabel
cd TryBabel
Go to https://babeljs.io/setup.html and click "CLI"
You need a package.json, so use npm init and just press Enter a few times
It should lead you to install
a. npm install --save-dev #babel/core #babel/cli
b. now look at your package.json. Remove the script about test but use this: "build": "babel src -d lib"
Now npm run build or ./node_modules/.bin/babel src -d lib should work, but make sure you have some .js files in the src folder. The transpiled result will be in the lib folder.
Now to transpile things into "pre ES6", just follow the #babel/preset-env instructions:
a. npm install #babel/preset-env --save-dev
b. make your babel.config.json to contain { "presets": ["#babel/preset-env"] }
Now you can use npm run build to transpile once, or use ./node_modules/.bin/babel src -d lib --watch to keep on running it and "watch" the src folder and transpile files in it when the files change.
To do minification or make it work with JSX/React, see
https://babeljs.io/docs/en/babel-preset-minify
and
https://babeljs.io/docs/en/babel-preset-react
and make sure your babel.config.json file looks like:
{
"presets": [
[
"#babel/preset-env",
{
"useBuiltIns": "entry"
}
],
["#babel/preset-react"],
["minify"]
]
}
and remove minify if you don't want the code to be minified.
I seem to absolutely not grasp where to put root programmatic options for the babel.
If I have a monorepo and need to tell the different sub packages that they shall look upwards for my babel.config.js then I should put rootMode: "upwards" into the .babelrc of the sub packages, correct? This does not work, because of the resulting error
Error: .rootMode is only allowed in root programmatic options
Somehow I simply can't find any example of where to put/use root programmatic options... Can anyone point me to the right direction?
If you are using Webpack, you need to put it there.
module: {
[..]
rules: [
// Transpile ES6 Javascript into ES5 with babel loader
{
test: /\.jsx?$/,
exclude: [/node_modules/, /json/],
loader: 'babel-loader',
options: {
rootMode: 'upward'
},
},
[..]
],
[..]
},
Otherwise I had the same issue than you, I can't put it in the package.json file using the key babel.
Any API-related options are called programmatic options. Take a look at my discussion with the primary maintainer of Babel: https://github.com/babel/babel/discussions/14405.
It's when you specify them directly to Babel (babel.transformSync(code, programmaticOptions) or to the Babel integration you are using (e.g. babel-loader, which can pass them to its internal babel.transform call). In other words, not in presets or config files. [...]
by #nicolo-ribaudo - Babel core team.
I got this error using my (probably non-standard) monorepo setup where I have top-level subdirectories for each of my packages. No top-level package. When I upgraded to Babel 7, my Jest tests were no longer transforming packages that were yarn linked into the package where I was running Jest.
I added a top-level babel.config.js as part of Babel's monorepo instructions. I had rootMode: "upwards" in these three places:
ui-package/webpack.config.js for transforming the app.
ui-package/babel-jest.js for the tests, where it appeared like:
module.exports = require("babel-jest").createTransformer({
rootMode: "upward",
})
and was referenced from jest.config.js in that same dir like:
transform: {
"^.+\\.jsx?$": "./babel-jest.js",
},
And in /babel.config.js, the newly added top-level babel conf file.
Removing it from the last one removed the error.
Babel doesn't find all of my .js/.es6 files in my directory.
I have this directory structure:
src/
assets/
sample/
models.es6
scripts/
playground.es6
If I run babel src --out-dir dist --source-maps --copy-files --presets env, it only transpiles /src/assets/sample/models.es6 and doesnt go through src/scripts/playground.es6.
What am I doing wrong?
Looking forward to your response!
You can do like below :
babel src/** --out-dir lib
more at official doc
Compile Directories
Compile the entire src directory and output it to the lib directory. You may use --out-dir or -d. This doesn’t overwrite any other files or directories in lib.
if you still stuck, you can use gulp or grunt or webpack to load/transpile mupltiple directives from different locations.
Hope it helps
I found the problem. It has barely to do with Babel.
Inside the src/assets/** is my Realm database sample.realm (https://realm.io). The file itself doesnt cause the problem. But if you open the sample.realm file with Realm Studio on MacOSX, a file called sample.realm.note gets created. This file causes babel to not exit the transpile task.
I was recently trying to debug errors in a next.js getting started project and realized that it didn't like a .babelrc file in a parent directory.
My questions are:
Why is the project throwing an error on a .babelrc configuration file in a parent directory that's not part of the project? Does it recursively look for a babel configuration file in all parent directories or did I at some point configure babel to look at that config file? How can I check what that configuration is?
Is this a quirk of next.js that makes it look for a configuration file in a parent directory?
I forgot if I had added that .babelrc configuration in the parent directory - is that something that I needed? What is the configuration? How should I update it to make the error go away?
ERROR in ./pages/index.js
Module build failed: ReferenceError: [BABEL] /Users/me/Projects/foo/foo-web/pages/index.js:
Using removed Babel 5 option: /Users/me/Projects/.babelrc.optional
- Put the specific transforms you want in the `plugins` option
.babelrc
"optional": ["es7.classProperties"]
babel is looking first .babelrc file is present in the root directory
you have to create the .babelrc file
npm install babel-plugin-transform-runtime
insert to .babelrc
{
"plugins": [
"transform-runtime"
]
}
more info
I'm having trouble finding the correct way to use babel to allow me to use jsx in serverside.
Node-jsx was deprecated for babel. It seems like babel-core/register is whats supposed to be used but I still get unexpected token issues.
I created a repo with the problem im having.
https://github.com/pk1m/Stackoverflow-helpme
When I run node app or npm run watch-js I keep getting unexpected token referring to the JSX code '<'.
How do I get babel to transpile JSX, or am I completely off, thanks.
You need to use babel-register (npm i babel-register --save). And run on your server:
require('babel-register')({
stage: 0
});
You can omit stage 0 if you aren't using experimental babel features. Also you might prefer to put those options in .babelrc instead.
Note that it will only work for files required AFTER calling that (so it would not have an effect on the file you include it in).
You could also have the presets and other options in a .babelrc file.
For babel 6x:
npm i babel-register babel-preset-es2015 babel-preset-react --save
require('babel-register')({
presets: ['es2015', 'react']
});
Note: there are also stage 0-2 presets.
For watching as you've written in your package.json you could try a CLI command like the one facebook are suggesting in the note here (or use webpack):
babel --presets react es2015 --watch app/ --out-dir build/