From c5d5c8dfed74ee3dce8e1235a19b07c4b755d1a2 Mon Sep 17 00:00:00 2001
From: Aaron Reisman <aaron@lifeiscontent.net>
Date: Wed, 4 Sep 2019 03:22:04 -0700
Subject: [PATCH] Update utilites.ts to cover null case (#5110)

* Update utilites.ts

* fix edge case when data is resolved to null

* Update packages/graphql-anywhere/src/__tests__/utilities.ts

Co-Authored-By: Carlo Palinckx <carlopalinckx@gmail.com>
---
 packages/graphql-anywhere/src/__tests__/utilities.ts | 6 +++++-
 packages/graphql-anywhere/src/utilities.ts           | 5 ++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/packages/graphql-anywhere/src/__tests__/utilities.ts b/packages/graphql-anywhere/src/__tests__/utilities.ts
index a993a8edbaa..ab33030421c 100644
--- a/packages/graphql-anywhere/src/__tests__/utilities.ts
+++ b/packages/graphql-anywhere/src/__tests__/utilities.ts
@@ -108,7 +108,11 @@ describe('utilities', () => {
       expect(filter(doc, arrayData)).toEqual(filteredArrayData);
     });
 
-    it('can filter data for fragments ', () => {
+    it('can short circuit when data is null', () => {
+      expect(filter(doc, null)).toEqual(null);
+    });
+
+    it('can filter data for fragments', () => {
       expect(filter(fragment, data)).toEqual(filteredData);
     });
 
diff --git a/packages/graphql-anywhere/src/utilities.ts b/packages/graphql-anywhere/src/utilities.ts
index 732f7e92598..b71c1a0c49c 100644
--- a/packages/graphql-anywhere/src/utilities.ts
+++ b/packages/graphql-anywhere/src/utilities.ts
@@ -13,6 +13,8 @@ export function filter<FD = any, D extends FD = any>(
   data: D,
   variableValues: VariableMap = {},
 ): FD {
+  if (data === null) return data;
+
   const resolver = (
     fieldName: string,
     root: any,
@@ -63,7 +65,8 @@ function hasVariableInclusions(
   directives: ReadonlyArray<DirectiveNode>,
 ): boolean {
   return getInclusionDirectives(directives).some(
-    ({ ifArgument }) => ifArgument.value && ifArgument.value.kind === 'Variable',
+    ({ ifArgument }) =>
+      ifArgument.value && ifArgument.value.kind === 'Variable',
   );
 }