Add env query parameter.

[moimael]

Allow to override BABEL_ENV/NODE_ENV at loader-level. Useful for isomorphic applications which have separate babel config for client and server.

fix #283

Please check if the PR fulfills these requirements

• Tests for the changes have been added (not sure if needed here, but i'd like to hear what maintainers think)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Feature

What is the current behavior? (You can also link to an open issue here)
See #283

What is the new behavior?
If forceEnv is set as loader option, use that instead of BABEL_ENV/NODE_ENV

Does this PR introduce a breaking change?

• No

[codecov-io]

Codecov Report

Merging #368 into master will increase coverage by 0.12%.

@@            Coverage Diff             @@
##           master     #368      +/-   ##
==========================================
+ Coverage   80.92%   81.04%   +0.12%     
==========================================
  Files           6        6              
  Lines         152      153       +1     
  Branches       33       33              
==========================================
+ Hits          123      124       +1     
  Misses         13       13              
  Partials       16       16

Impacted Files	Coverage Δ
src/index.js	82.85% <100%> (+0.24%)	✅

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[moimael]

Can someone have a look ?

[hiroppy]

@moimael Sorry for the late reply. It looks good to me. cc: @babel/webpack

[danez]

Thanks you

[tleunen]

@moimael Could you explain how to use it?
I get the changes you've made in the PR, then try to add the option, but when my app loads, I'm getting this error now:

Module build failed: ReferenceError: [BABEL] /src/index.js: Unknown option: base.forceEnv.

Here's the loader:

{
    test: /\.jsx?$/,
    exclude: /node_modules/,
    use: [
        loader: 'babel-loader',
        options: {
            forceEnv: 'local'
        }
    ]
},

[moimael]

How did you install it ? Using file:// ? Did you rebuild it before ?

[tleunen]

Manually added the missing piece, but obviously I missed delete userOptions.forceEnv;.

It's good now, thx :)
It was just for a quick testing

[chrisvasz]

This feature isn't working for me. Looking at the code, it looks like this change only affects the cacheIdentifier, but doesn't actually change the env for the Babel transform operation. I had to add something like this to index.js to make babel-loader actually use the specified environment:

var env = userOptions.forceEnv || process.env.BABEL_ENV || process.env.NODE_ENV;
// ...
var tmp = process.env.BABEL_ENV;        // added
process.env.BABEL_ENV = env;            // added
result = transpile(source, options);
process.env.BABEL_ENV = tmp;            // added

I'm happy to send this in a PR, but I wanted to make sure I'm not missing something first.

[moimael]

@chrisvasz It is working well for me, so I'm a bit surprised. How do you use it ? I might very well have missed something since it's my first contribution to anything babel related.

EDIT: Ok I see what you mean, I'm quite ashamed to have missed that, I'm indeed only changing the cache identifier. I still don't quite understand why it works for me. I think a PR would be great !

[tleunen]

Same for me. it works well.

I don't think it makes sense to update BABEL_ENV. The custom value is passed to babel when compiling, which is why it works.

[chrisvasz]

@tleunen I'm not seeing where the custom value gets passed into Babel. userOptions.forceEnv is used as part of the cacheIdentifier, then deleted before being assigned into options. I dug in because it wasn't working for me... I'm happy to be told that I'm doing something wrong, but looking at the code, I'm not sure how this could work.

[tleunen]

Oh, you're right, I missed the stringify function when reading the code.

[moimael]

More like forceEnv: 'client'