feat(dev): auto process.env.PORT

packages/@moonreach/nodepack/src/commands/dev.js

@@ -5,15 +5,32 @@ module.exports = (api, options) => {
   api.registerCommand('dev', {
     description: 'Build and live-reload the app',
     usage: 'nodepack dev [entry]',
+    options: {
+      '-p, --port [port]': 'Specify a default port for process.env.PORT (it may automatically change if not available)',
+    },
   }, async (args) => {
     const path = require('path')
     const { info, error, chalk } = require('@moonreach/nodepack-utils')
 
     info(chalk.blue('Preparing development pack...'))
 
+    // Entry
     const { getDefaultEntry } = require('../util/defaultEntry.js')
     options.entry = getDefaultEntry(api, options, args)
 
+    const moreEnv = {}
+
+    // Default port
+    if (!process.env.PORT || args.port) {
+      const { getDefaultPort } = require('../util/defaultPort')
+      const port = await getDefaultPort(api, options, args)
+      moreEnv.PORT = port
+      if (api.service.env === 'development') {
+        info(chalk.blue(`\`process.env.PORT\` has been set to ${port}`))
+      }
+    }
+
+    // Build
     const webpack = require('webpack')
     const webpackConfig = await api.resolveWebpackConfig()
     const execa = require('execa')
@@ -32,6 +49,7 @@ module.exports = (api, options) => {
         if (err) {
           error(err)
         } else {
+          // Kill previous process
           if (child) {
             child.kill()
           }
@@ -45,15 +63,18 @@ module.exports = (api, options) => {
               info(chalk.blue('App starting...'))
             }
 
+            // Built entry file
             const file = api.resolve(path.join(webpackConfig.output.path, 'app.js'))
 
+            // Spawn child process
             child = execa('node', [
               file,
             ], {
               stdio: ['inherit', 'inherit', 'inherit'],
               cwd: api.getCwd(),
               cleanup: true,
               shell: false,
+              env: moreEnv,
             })
 
             child.on('error', err => {

packages/@moonreach/nodepack/src/lib/options.js

@@ -12,6 +12,7 @@ exports.defaultOptions = function () {
     externals: true,
     parallel: hasMultipleCores(),
     transpileDependencies: [],
+    defaultPort: 4000,
   }
 }
 

packages/@moonreach/nodepack/src/util/defaultPort.js

@@ -0,0 +1,14 @@
+/** @typedef {import('../lib/PackPluginAPI.js')} PackPluginApi */
+/** @typedef {import('../lib/options.js').ProjectOptions} ProjectOptions */
+
+/**
+ * @param {PackPluginApi} api
+ * @param {ProjectOptions} options
+ */
+exports.getDefaultPort = async function (api, options, args) {
+  const portfinder = require('portfinder')
+  const result = await portfinder.getPortPromise({
+    port: args.port || options.defaultPort,
+  })
+  return result
+}

packages/@moonreach/nodepack/types/options.d.ts

@@ -1,24 +1,33 @@
 import Config from 'webpack-chain'
 
 export interface ProjectOptions {
-  /** folder output for prod build */
+  /** Folder output for prod build */
   outputDir?: string
-  /** folder containing source */
+  /**
+   * Folder containing source.  
+   * By default will be aliased to `@/`  
+   * (for example, `@/lib/foo.js` will be resolved as `src/lib/foo.js`).
+   */
   srcDir?: string
-  /** entry file */
+  /** Entry file (relative to project root) */
   entry?: string
-  /** enable sourcemaps in production build */
+  /** Enable sourcemaps in production build (can slow down build) */
   productionSourceMap?: boolean
-  /** webpack externals */
+  /** Webpack externals packages */
   externals?: any
-  /** whitelist option for webpack-node-externals */
+  /** Whitelist option for webpack-node-externals */
   nodeExternalsWhitelist?: any
-  /** modify webpack config with webpack-chain */
+  /** Modify webpack config with webpack-chain */
   chainWebpack?: (config: Config) => void
-  /** enable parallel compilation */
+  /** Enable parallel compilation */
   parallel?: boolean
-  /** force transpile node_modules packages with babel */
+  /** Force transpile `node_modules` packages with babel */
   transpileDependencies?: Array.<string | RegExp>
-  /** options for 3rd-party plugins */
+  /**
+   * Default port for `process.env.PORT` if it is not defined.  
+   * It will change to a free port automatically if it is not available.
+   */
+  defaultPort?: number
+  /** Options for 3rd-party plugins */
   pluginOptions?: any
 }