Initial Sample.

graphql-subscription/node_modules/zen-observable/scripts/babel-plugins.js

@@ -0,0 +1,16 @@
+module.exports = [
+  '@babel/plugin-transform-arrow-functions',
+  '@babel/plugin-transform-block-scoped-functions',
+  '@babel/plugin-transform-block-scoping',
+  '@babel/plugin-transform-classes',
+  '@babel/plugin-transform-computed-properties',
+  '@babel/plugin-transform-destructuring',
+  '@babel/plugin-transform-duplicate-keys',
+  '@babel/plugin-transform-for-of',
+  '@babel/plugin-transform-literals',
+  '@babel/plugin-transform-modules-commonjs',
+  '@babel/plugin-transform-parameters',
+  '@babel/plugin-transform-shorthand-properties',
+  '@babel/plugin-transform-spread',
+  '@babel/plugin-transform-template-literals',
+];

graphql-subscription/node_modules/zen-observable/scripts/build.js

@@ -0,0 +1,7 @@
+const { execSync } = require('child_process');
+const plugins = require('./babel-plugins');
+
+execSync('babel src --out-dir lib --plugins=' + plugins.join(','), {
+  env: process.env,
+  stdio: 'inherit',
+});

graphql-subscription/node_modules/zen-observable/scripts/mocha-require.js

@@ -0,0 +1,3 @@
+require('@babel/register')({
+  plugins: require('./babel-plugins'),
+});