1 files changed, 56 insertions, 43 deletions
diff --git a/babel.config.js b/babel.config.js
index 05554e8763e..d99f41e8677 100644
--- a/babel.config.js
+++ b/babel.config.js
@@ -1,52 +1,65 @@
 /* eslint-disable import/no-commonjs, filenames/match-regex */
+module.exports = function(api) {
+  const validEnv = ['development', 'test', 'production'];
+  const currentEnv = api.env();
+  const isDevelopmentEnv = api.env('development');
+  const isProductionEnv = api.env('production');
+  const isTestEnv = api.env('test');
 
-const BABEL_ENV = process.env.BABEL_ENV || process.env.NODE_ENV || null;
+  if (!validEnv.includes(currentEnv)) {
+    throw new Error(
+      'Please specify a valid `NODE_ENV` or ' +
+        '`BABEL_ENV` environment variables. Valid values are "development", ' +
+        '"test", and "production". Instead, received: ' +
+        JSON.stringify(currentEnv) +
+        '.'
+    )
+  }
 
-const presets = [
-  [
-    '@babel/preset-env',
-    {
-      modules: false,
-      targets: {
-        ie: '11',
+  const presets = [
+    [
+      '@babel/preset-env',
+      {
+        modules: false,
+        targets: {
+          ie: '11',
+        },
       },
-    },
-  ],
-];
+    ]
+  ];
 
-// include stage 3 proposals
-const plugins = [
-  '@babel/plugin-syntax-dynamic-import',
-  '@babel/plugin-syntax-import-meta',
-  '@babel/plugin-proposal-class-properties',
-  '@babel/plugin-proposal-json-strings',
-  '@babel/plugin-proposal-private-methods',
-];
+  // include stage 3 proposals
+  const plugins = [
+    '@babel/plugin-syntax-dynamic-import',
+    '@babel/plugin-syntax-import-meta',
+    '@babel/plugin-proposal-class-properties',
+    '@babel/plugin-proposal-json-strings',
+    '@babel/plugin-proposal-private-methods',
+  ];
 
-// add code coverage tooling if necessary
-if (BABEL_ENV === 'coverage') {
-  plugins.push([
-    'babel-plugin-istanbul',
-    {
-      exclude: ['spec/javascripts/**/*', 'app/assets/javascripts/locale/**/app.js'],
-    },
-  ]);
-}
+  // add code coverage tooling if necessary
+  if (isTestEnv) {
+    plugins.push([
+      'babel-plugin-istanbul',
+      {
+        exclude: ['spec/javascripts/**/*', 'app/assets/javascripts/locale/**/app.js'],
+      },
+    ]);
+  }
 
-// add rewire support when running tests
-if (BABEL_ENV === 'karma' || BABEL_ENV === 'coverage') {
-  plugins.push('babel-plugin-rewire');
-}
+  // add rewire support when running tests
+  if (isTestEnv) {
+    plugins.push('babel-plugin-rewire');
+  }
 
-// Jest is running in node environment, so we need additional plugins
-const isJest = Boolean(process.env.JEST_WORKER_ID);
-if (isJest) {
-  plugins.push('@babel/plugin-transform-modules-commonjs');
-  /*
-  without the following, babel-plugin-istanbul throws an error:
-  https://gitlab.com/gitlab-org/gitlab-ce/issues/58390
-  */
-  plugins.push('babel-plugin-dynamic-import-node');
-}
+  if (isTestEnv) {
+    plugins.push('@babel/plugin-transform-modules-commonjs');
+    /*
+    without the following, babel-plugin-istanbul throws an error:
+    https://gitlab.com/gitlab-org/gitlab-ce/issues/58390
+    */
+    plugins.push('babel-plugin-dynamic-import-node');
+  }
 
-module.exports = { presets, plugins };
+  return { presets: presets, plugins: plugins};
+};