From fb44c9868c28b44e4b7cd92e142f717f027aad77 Mon Sep 17 00:00:00 2001
From: Paul Grenier <pgrenier@gmail.com>
Date: Tue, 22 Sep 2015 20:05:12 -0400
Subject: [PATCH] adding `try... catch...` back to handle wrapped non-async
 cases

---
 index.js     | 10 +++++++---
 test/test.js | 16 ++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index 4f4e1bf..0c5669b 100644
--- a/index.js
+++ b/index.js
@@ -33,9 +33,13 @@ function compose(middleware){
     function dispatch(i) {
       const fn = middleware[i] || next
       if (!fn) return Promise.resolve()
-      return Promise.resolve(fn(context, function next() {
-        return dispatch(i + 1)
-      }))
+      try {
+        return Promise.resolve(fn(context, function next() {
+          return dispatch(i + 1)
+        }))
+      } catch(err) {
+        return Promise.reject(err);
+      }
     }
   }
 }
diff --git a/test/test.js b/test/test.js
index c34f394..814bcb1 100644
--- a/test/test.js
+++ b/test/test.js
@@ -163,4 +163,20 @@ describe('Koa Compose', function(){
       assert(called)
     })
   })
+
+  it('should handle errors in wrapped non-async functions', function () {
+    var arr = [];
+    var stack = [];
+
+    stack.push(function () {
+      throw new Error();
+    })
+
+    return compose(stack.map(co.wrap))({}).then(function () {
+      throw 'promise was not rejected'
+    })
+    .catch(function (e) {
+      e.should.be.instanceof(Error)
+    })
+  })
 })