Set environment variable, NODE_ENV, inside of `runCommand` (also adds --env option to CLI).

packages/neutrino/bin/neutrino

@@ -26,6 +26,11 @@ const args = yargs
     default: [],
     global: true
   })
+  .option('env', {
+    description: 'The value for the environment variable, NODE_ENV',
+    string: true,
+    global: true
+  })
   .command('start', 'Build a project in development mode')
   .command('build', 'Compile the source directory to a bundled build')
   .command('test [files..]', 'Run all suites from the test directory or provided files', {
@@ -48,7 +53,6 @@ const args = yargs
   .argv;
 
 function run(command, args) {
-  const environments = { build: 'production', start: 'development', test: 'test' };
   const pkg = optional(join(process.cwd(), 'package.json')) || {};
   const pkgMiddleware = pathOr([], ['neutrino', 'use'], pkg);
   const middleware = [...new Set(pkgMiddleware.concat(args.use))];
@@ -56,8 +60,6 @@ function run(command, args) {
   const config = pathOr({}, ['neutrino', 'config'], pkg);
   const api = new Neutrino(Object.assign(options, { config }));
 
-  process.env.NODE_ENV = environments[command];
-
   // Grab all middleware and merge them into a single webpack-chain config instance
   api.import(middleware);
 

packages/neutrino/src/neutrino.js

@@ -5,6 +5,7 @@ const webpack = require('webpack');
 const Config = require('webpack-chain');
 const ora = require('ora');
 const merge = require('deepmerge');
+const { defaultTo } = require('ramda');
 const requireMiddleware = require('./requireMiddleware');
 
 const normalizePath = (path, root) => (isAbsolute(path) ? path : join(root, path));
@@ -80,6 +81,12 @@ class Neutrino extends EventEmitter {
   }
 
   runCommand(command, args = {}, fn) {
+    process.env.NODE_ENV = defaultTo({
+      build: 'production',
+      start: 'development',
+      test: 'test'
+    }[command], args.env);
+
     return this
       .emitForAll(`pre${command}`, args)
       .then(fn)

packages/neutrino/test/api_test.js

@@ -94,6 +94,22 @@ test('import middleware for use', t => {
   t.notDeepEqual(api.getWebpackOptions(), {});
 });
 
+test('command sets correct NODE_ENV', t => {
+  const api = new Neutrino();
+
+  api.runCommand('build');
+  t.is(process.env.NODE_ENV, 'production');
+
+  api.runCommand('start');
+  t.is(process.env.NODE_ENV, 'development');
+
+  api.runCommand('test');
+  t.is(process.env.NODE_ENV, 'test');
+
+  api.runCommand('build', { env: 'development' });
+  t.is(process.env.NODE_ENV, 'development');
+});
+
 test('command emits events around execution', async (t) => {
   const api = new Neutrino();
   const events = [];