Some basic components for building forms.

lib/router-async.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const express = require('express');
+const InteroperableError = require('./InteroperableError');
 
 function safeHandler(handler) {
     return function(req, res) {
@@ -8,12 +9,45 @@ function safeHandler(handler) {
     };
 }
 
+function safeJSONHandler(handler) {
+    return function(req, res) {
+        handler(req, res).catch(error => {
+            const resp = {
+                message: error.message
+            };
+
+            if (error instanceof InteroperableError) {
+                resp.type = error.type;
+                resp.data = error.data;
+            }
+
+            res.status(500).json(resp);
+        });
+    };
+}
+
+function replaceLast(elems, replaceFn) {
+    if (elems.length === 0) {
+        return elems;
+    }
+
+    const lastElem = elems[elems.size - 1];
+    const replacement = replaceFn(lastElem);
+
+    elems[elems.size - 1] = replacement;
+
+    return elems;
+}
+
 function create() {
     const router = new express.Router();
 
-    router.getAsync = (path, asyncFn) => router.get(path, safeHandler(asyncFn));
+    router.getAsync = (path, ...handlers) => router.get(path, ...replaceLast(handlers, safeHandler));
 
-    router.postAsync = (path, asyncFn) => router.post(path, safeHandler(asyncFn));
+    router.getAsyncJSON = (path, ...handlers) => router.get(path, ...replaceLast(handlers, safeJSONHandler));
+    router.postAsyncJSON = (path, ...handlers) => router.post(path, ...replaceLast(handlers, safeJSONHandler));
+    router.putAsyncJSON = (path, ...handlers) => router.put(path, ...replaceLast(handlers, safeJSONHandler));
+    router.deleteAsyncJSON = (path, ...handlers) => router.delete(path, ...replaceLast(handlers, safeJSONHandler));
 
     return router;
 }