Catch routing errors when attempting to render missing routes (#457)

* #456 dont throw on choo ssr missing a wildcard route

* update to catch any error occurring in rendering

* no console statement plz

* no comment either

Author: bendik

ssr/choo.js

@@ -63,17 +63,23 @@ module.exports.listRoutes = function (app) {
 module.exports.render = function (app, route, cb) {
   var state = {}
   state._experimental_prefetch = []
-  app.toString(route, state)
 
-  // TODO: replace with p-wait-all, once it knows how to handle an empty array.
-  Promise.all(state._experimental_prefetch)
-    .then(render, render)
+  return new Promise(function (resolve, reject) {
+    // First pass to populate prefetch
+    try {
+      app.toString(route, state)
+    } catch (err) {
+      return reject(err)
+    }
+    resolve(state._experimental_prefetch)
+  }).then(function (prefetches) {
+    return Promise.all(prefetches)
+  }).then(render).catch(cb)
 
   function render () {
-    var body = app.toString(route, state)
-    delete state._experimental_prefetch // State needs to be serializable.
     var res = { state: state }
-    if (body) res.body = body
+    res.body = app.toString(route, state)
+    delete res.state._experimental_prefetch // State needs to be serializable.
     if (app.state.title) res.title = app.state.title
     if (app.state.language) res.language = app.state.language
     if (app.selector) res.selector = app.selector