Migrate to TS: rename .js to .ts and fix everything in latter PRs (graphql#3088)

using this `find src -name "*.js" -exec sh -c 'git mv "$0" "${0%.js}.ts"' {} \;` shell command renamed all files in `src`

Author: saihaj

src/jsutils/Maybe.ts

@@ -1,2 +1,6 @@
+<<<<<<< HEAD
 /** Conveniently represents flow's "Maybe" type https://flow.org/en/docs/types/maybe/ */
+=======
+// Conveniently represents flow's "Maybe" type https://flow.org/en/docs/types/maybe/
+>>>>>>> Migrate to TS: rename `.js` to `.ts` and fix everything in latter PRs (#3088)
 export type Maybe<T> = null | undefined | T;

src/jsutils/ObjMap.js

@@ -1,3 +1,4 @@
+<<<<<<< HEAD
 export interface ObjMap<T> {
   [key: string]: T;
 }
@@ -11,3 +12,12 @@ export interface ReadOnlyObjMap<T> {
 export type ReadOnlyObjMapLike<T> =
   | ReadOnlyObjMap<T>
   | { readonly [key: string]: T };
+=======
+export type ObjMap<T> = { [key: string]: T; __proto__: null; ... };
+export type ObjMapLike<T> = ObjMap<T> | { [key: string]: T; ... };
+
+export type ReadOnlyObjMap<T> = { +[key: string]: T; __proto__: null; ... };
+export type ReadOnlyObjMapLike<T> =
+  | ReadOnlyObjMap<T>
+  | { +[key: string]: T; ... };
+>>>>>>> Migrate to TS: rename `.js` to `.ts` and fix everything in latter PRs (#3088)

src/jsutils/ObjMap.ts

@@ -1 +1 @@
-export type PromiseOrValue<T> = Promise<T> | T;
+export type PromiseOrValue<+T> = Promise<T> | T;

src/jsutils/PromiseOrValue.ts

@@ -2,8 +2,12 @@
  * Returns true if the provided object implements the AsyncIterator protocol via
  * implementing a `Symbol.asyncIterator` method.
  */
-export function isAsyncIterable(
-  maybeAsyncIterable: any,
-): maybeAsyncIterable is AsyncIterable<unknown> {
+declare function isAsyncIterable(
+  value: mixed,
+  // $FlowFixMe[invalid-in-rhs]
+): boolean %checks(value instanceof AsyncIterable);
+
+// eslint-disable-next-line no-redeclare
+export function isAsyncIterable(maybeAsyncIterable) {
   return typeof maybeAsyncIterable?.[Symbol.asyncIterator] === 'function';
 }

src/jsutils/isAsyncIterable.ts

@@ -2,6 +2,10 @@
  * Returns true if the value acts like a Promise, i.e. has a "then" function,
  * otherwise returns false.
  */
-export function isPromise(value: any): value is Promise<unknown> {
+declare function isPromise(value: mixed): boolean %checks(value instanceof
+  Promise);
+
+// eslint-disable-next-line no-redeclare
+export function isPromise(value) {
   return typeof value?.then === 'function';
 }