Merge pull request #744 from ParsePlatform/flovilmart.betterPromiseRouter

Better promise router

Author: flovilmart

spec/PromiseRouter.spec.js

@@ -0,0 +1,26 @@
+var PromiseRouter = require("../src/PromiseRouter").default;
+
+describe("PromiseRouter", () => {
+  
+  it("should properly handle rejects", (done) => {
+    var router = new PromiseRouter();
+    router.route("GET", "/dummy", (req)=> {
+      return Promise.reject({
+        error: "an error",
+        code: -1
+      })
+    }, (req) => {
+      fail("this should not be called");
+    });
+    
+    router.routes[0].handler({}).then((result) => {
+      console.error(result);
+      fail("this should not be called");
+      done();
+    }, (error)=> {
+      expect(error.error).toEqual("an error");
+      expect(error.code).toEqual(-1);
+      done();
+    });
+  });
+})

src/PromiseRouter.js

@@ -49,17 +49,11 @@ export default class PromiseRouter {
     if (handlers.length > 1) {
       const length = handlers.length;
       handler = function(req) {
-        var next = function(i, req, res) {
-          if (i == length) {
-            return res;
-          }
-          let result =  handlers[i](req);
-          if (!result || typeof result.then !== "function") {
-            result = Promise.resolve(result);
-          }
-          return result.then((res) => (next(i+1, req, res))); 
-        }
-        return next(0, req);
+        return handlers.reduce((promise, handler) => {
+          return promise.then((result) => {
+            return handler(req);
+          });
+        }, Promise.resolve());
       }
     }