From 9c1e85306e2ab10fb1a458d889f0f9a613c7217d Mon Sep 17 00:00:00 2001
From: alexfaunt <alexfaunt@gmail.com>
Date: Wed, 15 Nov 2017 15:40:32 +0000
Subject: [PATCH] Maintain original errors where possible

---
 CHANGELOG.md            |  6 +++++-
 src/stitching/errors.ts | 12 +++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e24d3144335..4fa05091448 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,11 @@
 
 ### VNEXT
 
-* ...
+...
+
+### v2.8.1
+
+* When concatenating errors maintain a reference to the original for use downstream [Issue #480](https://github.com/apollographql/graphql-tools/issues/480) [PR #485](https://github.com/apollographql/graphql-tools/pull/485)
 
 ### v2.8.0
 
diff --git a/src/stitching/errors.ts b/src/stitching/errors.ts
index ee6869fed3b..fdac4cbb3d7 100644
--- a/src/stitching/errors.ts
+++ b/src/stitching/errors.ts
@@ -66,6 +66,14 @@ export function getErrorsFromParent(
   };
 }
 
+class CombinedError extends Error {
+  public errors: Error[];
+  constructor(message: string, errors: Error[]) {
+    super(message);
+    this.errors = errors;
+  }
+}
+
 export function checkResultAndHandleErrors(
   result: any,
   info: GraphQLResolveInfo,
@@ -80,8 +88,10 @@ export function checkResultAndHandleErrors(
     const errorMessage = result.errors
       .map((error: { message: string }) => error.message)
       .join('\n');
+    const combinedError = new CombinedError(errorMessage, result.errors);
+
     throw locatedError(
-      errorMessage,
+      combinedError,
       info.fieldNodes,
       responsePathAsArray(info.path),
     );