added 'spa-asset-test' config option. Fixes #36

lib/middleware-stack.js

@@ -214,20 +214,23 @@ class MiddlewareStack extends Array {
   }
 
   /* for any URL not matched by static (e.g. `/search`), serve the SPA */
-  addSpa (spa) {
+  addSpa (spa, assetTest) {
     this.push({
       optionDefinitions: {
         name: 'spa', alias: 's', type: String, typeLabel: '[underline]{file}',
         description: 'Path to a Single Page App, e.g. app.html.'
       },
       middleware: function (cliOptions) {
-        spa = t.isDefined(cliOptions.spa) ? cliOptions.spa : spa
+        spa = cliOptions.spa || spa || 'index.html'
+        assetTest = new RegExp(cliOptions['spa-asset-test'] || assetTest || '\\.')
         if (spa) {
-          const historyApiFallback = require('koa-connect-history-api-fallback')
+          const send = require('koa-send')
+          const _ = require('koa-route')
           debug('SPA', spa)
-          return historyApiFallback({
-            index: spa,
-            verbose: cliOptions.verbose
+          return _.get('*', function spaMw (ctx, route, next) {
+            const root = path.resolve(cliOptions.directory || process.cwd())
+            debug(`SPA request. Route: ${route}, isAsset: ${assetTest.test(route)}`)
+            return send(ctx, assetTest.test(route) ? route : spa, { root: root }).then(next)
           })
         }
       }