From 474540cfb97f98203d16ae853f1b3915fdcb9ae8 Mon Sep 17 00:00:00 2001
From: yaacovCR <yaacovCR@gmail.com>
Date: Fri, 19 Jul 2019 01:04:06 -0400
Subject: [PATCH] fix(stitching): support stitching unions of types with enums

Closes #13.
---
 src/stitching/checkResultAndHandleErrors.ts |  9 +++----
 src/test/testMergeSchemas.ts                | 28 +++++++++++++++++++++
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/stitching/checkResultAndHandleErrors.ts b/src/stitching/checkResultAndHandleErrors.ts
index f4ecf4f5e65..f472bc1dda5 100644
--- a/src/stitching/checkResultAndHandleErrors.ts
+++ b/src/stitching/checkResultAndHandleErrors.ts
@@ -2,10 +2,9 @@ import {
   GraphQLResolveInfo,
   responsePathAsArray,
   getNullableType,
-  isObjectType,
+  isCompositeType,
+  isLeafType,
   isListType,
-  isEnumType,
-  isScalarType,
   ExecutionResult,
   GraphQLError,
   GraphQLType,
@@ -60,7 +59,7 @@ export function handleResult(
 
   const nullableType = getNullableType(info.returnType);
 
-  if (isObjectType(nullableType) || isListType(nullableType)) {
+  if (isCompositeType(nullableType) || isListType(nullableType)) {
     annotateWithChildrenErrors(result, errors);
   }
 
@@ -70,7 +69,7 @@ export function handleResult(
 function parseOutputValue(type: GraphQLType, value: any) {
   if (isListType(type)) {
     return value.map((v: any) => parseOutputValue(getNullableType(type.ofType), v));
-  } else if (isEnumType(type) || isScalarType(type)) {
+  } else if (isLeafType(type)) {
     return type.parseValue(value);
   }
   return value;
diff --git a/src/test/testMergeSchemas.ts b/src/test/testMergeSchemas.ts
index 1c3f7f85097..d8c247415ca 100644
--- a/src/test/testMergeSchemas.ts
+++ b/src/test/testMergeSchemas.ts
@@ -130,6 +130,8 @@ let enumTest = `
     numericEnum: NumericEnum
   }
 
+  union UnionWithEnum = EnumWrapper
+
   schema {
     query: Query
   }
@@ -139,6 +141,7 @@ let enumTest = `
     numericEnum: NumericEnum
     listNumericEnum: [NumericEnum]
     wrappedEnum: EnumWrapper
+    unionWithEnum: UnionWithEnum
   }
 `;
 
@@ -153,6 +156,9 @@ enumSchema = makeExecutableSchema({
     NumericEnum: {
       TEST: 1,
     },
+    UnionWithEnum: {
+      __resolveType: () => 'EnumWrapper'
+    },
     Query: {
       color(parent, args) {
         return args.input === '#EA3232' ? args.input : null;
@@ -169,6 +175,12 @@ enumSchema = makeExecutableSchema({
           numericEnum: 1
         };
       },
+      unionWithEnum() {
+        return {
+          color: '#EA3232',
+          numericEnum: 1
+        };
+      },
     },
   },
 });
@@ -643,6 +655,12 @@ testCombinations.forEach(async combination => {
                 color
                 numericEnum
               }
+              unionWithEnum {
+                ... on EnumWrapper {
+                  color
+                  numericEnum
+                }
+              }
             }
           `,
         );
@@ -672,6 +690,12 @@ testCombinations.forEach(async combination => {
                 color
                 numericEnum
               }
+              unionWithEnum {
+                ... on EnumWrapper {
+                  color
+                  numericEnum
+                }
+              }
             }
           `,
         );
@@ -703,6 +727,10 @@ testCombinations.forEach(async combination => {
               color: 'RED',
               numericEnum: 'TEST',
             },
+            unionWithEnum: {
+              color: 'RED',
+              numericEnum: 'TEST',
+            },
           },
         });
         expect(mergedResult).to.deep.equal(enumResult);