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 <[email protected]>
apollographql · Sep 4, 2019 · c5d5c8d · c5d5c8d
1 parent cbdf03a
commit c5d5c8d
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git 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
@@ -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',
   );
 }