convert $Keys (flow) to keyof (TS)

Author: saihaj

src/language/visitor.ts

@@ -45,7 +45,7 @@ export type VisitFn<TAnyNode, TVisitedNode extends TAnyNode = TAnyNode> = (
  */
 export type VisitorKeyMap<KindToNode> = $ObjMap<
   KindToNode,
-  <T>(T) => ReadonlyArray<$Keys<T>>,
+  <T>(T) => ReadonlyArray<keyof T>,
 >;
 
 export const QueryDocumentKeys: VisitorKeyMap<ASTKindToNode> = {

src/utilities/findBreakingChanges.ts

@@ -65,12 +65,12 @@ export const DangerousChangeType = Object.freeze({
 });
 
 export type BreakingChange = {
-  type: $Keys<typeof BreakingChangeType>,
+  type: keyof typeof BreakingChangeType,
   description: string,
 };
 
 export type DangerousChange = {
-  type: $Keys<typeof DangerousChangeType>,
+  type: keyof typeof DangerousChangeType,
   description: string,
 };