Allow specifying environment variables for runner in options

Author: PikachuEXE

README.md

@@ -100,6 +100,7 @@ Can be configured with [UseEntry#options](https://webpack.js.org/configuration/m
 | `engine` | `"erb"` | ERB Template engine, `"erubi"`, `"erubis"` and `"erb"` are supported. |
 | `runner` | `"./bin/rails runner"` | Command to run Ruby scripts, relative to webpack's working directory. |
 | `timeoutMs` | `0` | Timeout for the runner task in milliseconds. `0` is no timeout. Set this if you want a hanging runner to error out the build. |
+| `env` | `process.env` | Environment variables to be passed to runner. |
 
 For example, if your webpack process is running in a subdirectory of your Rails project:
 

index.js

@@ -70,14 +70,19 @@ function parseDependencies (source, root) {
  * output transformed source.
  */
 function transformSource (runner, config, source, map, callback) {
+  var subprocessOptions = {
+    stdio: ['pipe', 'pipe', process.stderr],
+    env: config.env
+  }
+
   var child = spawn(
     runner.file,
     runner.arguments.concat(
       runnerPath,
       ioDelimiter,
       config.engine
     ),
-    { stdio: ['pipe', 'pipe', process.stderr] }
+    subprocessOptions
   )
   var timeoutId = config.timeoutMs
     ? setTimeout(function () { child.kill() }, config.timeoutMs)
@@ -186,7 +191,8 @@ module.exports = function railsErbLoader (source, map) {
   var config = defaults({}, getOptions(loader), {
     dependenciesRoot: 'app',
     runner: './bin/rails runner',
-    engine: 'erb'
+    engine: 'erb',
+    env: process.env
   })
 
   if (config.timeout !== undefined) {

test.js

@@ -91,6 +91,14 @@ test('loads through a Rails-like runner', function (done) {
   })
 })
 
+test('loads with env specified in option', function (done) {
+  compile2({ file: 'runner.js.erb', runner: './test/runner', env: {ENV: 'custom'} }, done, function (stats) {
+    expect(stats.compilation.errors).toEqual([])
+    expectInOutput("var env = 'custom'")
+    done()
+  })
+})
+
 test('does not error with large files', function (done) {
   compile2({ file: 'giant.js.erb' }, done, function (stats) {
     expect(stats.compilation.errors).toEqual([])

test/runner

@@ -1,7 +1,7 @@
 #! /usr/bin/env ruby
 
 require 'ostruct'
-Runner = OpenStruct.new(env: 'test')
+Runner = OpenStruct.new(env: ENV["ENV"] || 'test')
 
 def perform(file, *command_argv)
   ARGV.replace(command_argv)