Added overloaded signatures to partition function.

Author: jackson-blake

packages/apollo-gateway/src/FieldSet.ts

@@ -138,12 +138,12 @@ function mergeFieldNodeSelectionSets(
 ): SelectionNode[] {
   const [fieldNodes, fragmentNodes] = partition(
     selectionNodes,
-    (node: SelectionNode): node is FieldNode => node.kind === Kind.FIELD,
+    (node): node is FieldNode => node.kind === Kind.FIELD,
   );
 
   const [aliasedFieldNodes, nonAliasedFieldNodes] = partition(
     fieldNodes,
-    (node: FieldNode): node is FieldNode => !!node.alias,
+    node => !!node.alias,
   );
 
   const mergedFieldNodes = Array.from(

packages/apollo-gateway/src/utilities/array.ts

@@ -19,7 +19,15 @@ export function compactMap<T, U>(
 export function partition<T, U extends T>(
   array: T[],
   predicate: (element: T, index: number, array: T[]) => element is U,
-): [U[], T[]] {
+): [U[], T[]];
+export function partition<T>(
+  array: T[],
+  predicate: (element: T, index: number, array: T[]) => boolean,
+): [T[], T[]];
+export function partition<T>(
+  array: T[],
+  predicate: (element: T, index: number, array: T[]) => boolean,
+): [T[], T[]] {
   array.map;
   return array.reduce(
     (accumulator, element, index) => {
@@ -30,7 +38,7 @@ export function partition<T, U extends T>(
         accumulator
       );
     },
-    [[], []] as [U[], T[]],
+    [[], []] as [T[], T[]],
   );
 }