Support passing customized webpack config via graphpack.config.js

glennreyes · glennreyes · commit 25d03c187485 · 2018-10-16T16:20:22.000+02:00
diff --git a/bin/graphpack.js b/bin/graphpack.js
@@ -3,16 +3,14 @@ const nodemon = require('nodemon');
 const path = require('path');
 const { once } = require('ramda');
 const webpack = require('webpack');
-const webpackConfig = require('../config/webpack.config');
+const { loadWebpackConfig } = require('../config');
 
-const compiler = webpack(webpackConfig);
-
-const startDevServer = () => {
+const startDevServer = ({ compiler, config }) => {
   const serverPaths = Object.keys(compiler.options.entry).map(entry =>
     path.join(compiler.options.output.path, `${entry}.js`),
   );
   compiler.watch(
-    webpackConfig.watchOptions,
+    config.watchOptions,
     once((error, stats) => {
       if (error || stats.hasErrors()) {
         throw Error(error || stats.toJson().errors);
@@ -26,14 +24,25 @@ const startDevServer = () => {
   );
 };
 
-const createProductionBuild = () => {
+const createProductionBuild = ({ compiler }) => {
   compiler.run((error, stats) => {
     if (error || stats.hasErrors()) {
       throw Error(error || stats.toJson().errors);
     }
   });
 };
 
-require('yargs')
-  .command(['$0', 'dev'], 'Start graphpack dev server', {}, startDevServer)
-  .command('build', 'Create production build', {}, createProductionBuild).argv;
+const startGraphPack = async () => {
+  const config = await loadWebpackConfig();
+  const compiler = webpack(config);
+
+  require('yargs')
+    .command(['$0', 'dev'], 'Start graphpack dev server', {}, () =>
+      startDevServer({ compiler, config }),
+    )
+    .command('build', 'Create production build', {}, () =>
+      createProductionBuild({ compiler }),
+    ).argv;
+};
+
+startGraphPack();
diff --git a/config/index.js b/config/index.js
@@ -0,0 +1,21 @@
+const cosmiconfig = require('cosmiconfig');
+const defaultConfig = require('./webpack.config');
+
+const explorer = cosmiconfig('graphpack').search();
+
+const loadWebpackConfig = async () => {
+  const result = await explorer;
+  const userConfig = result
+    ? typeof result.config === 'function'
+      ? result.config(defaultConfig.mode)
+      : result.config
+    : {};
+
+  if (typeof userConfig.webpack === 'function') {
+    return userConfig.webpack(defaultConfig);
+  }
+
+  return defaultConfig;
+};
+
+exports.loadWebpackConfig = loadWebpackConfig;
diff --git a/config/webpack.config.js b/config/webpack.config.js
@@ -3,6 +3,8 @@ const path = require('path');
 const webpack = require('webpack');
 const nodeExternals = require('webpack-node-externals');
 
+const IS_DEV = process.env.NODE_ENV !== 'production';
+
 module.exports = {
   entry: {
     // We take care of setting up the server under ./server.js
@@ -12,7 +14,7 @@ module.exports = {
   // its node_modules dependencies. This creates an externals function that
   // ignores node_modules when bundling in Webpack.
   externals: [nodeExternals({ whitelist: [/^graphpack$/] })],
-  mode: 'development',
+  mode: IS_DEV ? 'development' : 'production',
   module: {
     rules: [
       {
diff --git a/package.json b/package.json
@@ -13,6 +13,7 @@
     "@babel/preset-env": "^7.1.0",
     "apollo-server": "2.1.0",
     "babel-loader": "^8.0.4",
+    "cosmiconfig": "^5.0.6",
     "friendly-errors-webpack-plugin": "^1.7.0",
     "graphql": "^0.13.2",
     "graphql-tag": "^2.9.2",
