Add browser-sync (#97)

This adds browser-sync in development mode only, copied across from the
existing prototype kit.

Fixes #77

Author: frankieroberto

lib/index.js

@@ -1,5 +1,8 @@
 const { join } = require('node:path')
 
+const browserSync = require('browser-sync')
+const { createProxyMiddleware } = require('http-proxy-middleware')
+
 const build = require('./build')
 const expressMiddleware = require('./express-middleware')
 const expressSettings = require('./express-settings')
@@ -79,7 +82,29 @@ NHSPrototypeKit.prototype.start = async function (port) {
     if (nodeEnv === 'production') {
       console.info(`Running on port ${availablePort}`)
     } else {
-      console.info(`Running at http://localhost:${availablePort}/`)
+      const bs = browserSync.create()
+
+      bs.init({
+        port: availablePort,
+        files: ['views/**/*.*', 'assets/**/*.*'],
+
+        // We create our own proxy middleware here
+        // as the default proxy option does not work
+        // on GitHub Codespaces.
+        middleware: createProxyMiddleware({
+          changeOrigin: true,
+          target: `http://localhost:${availablePort}`
+        }),
+        server: {
+          baseDir: join(__dirname, 'public')
+        },
+
+        ghostMode: false,
+        open: false,
+        notify: true,
+        watch: true,
+        ui: false
+      })
     }
   })
 }