Fix fromJS declaration for greater compatibility (#1936)

immutable-js · Mar 10, 2023 · 376944d · 376944d
1 parent 14832ca
commit 376944d
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Showing 2 changed files with 19 additions and 5 deletions.
diff --git a/type-definitions/immutable.d.ts b/type-definitions/immutable.d.ts
@@ -5161,18 +5161,18 @@ declare namespace Immutable {
    * [3]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#the_iterable_protocol
    *      "The iterable protocol"
    */
+  function fromJS<JSValue>(
+    jsValue: JSValue,
+    reviver?: undefined
+  ): FromJS<JSValue>;
   function fromJS(
     jsValue: unknown,
-    reviver: (
+    reviver?: (
       key: string | number,
       sequence: Collection.Keyed<string, unknown> | Collection.Indexed<unknown>,
       path?: Array<string | number>
     ) => unknown
   ): Collection<unknown, unknown>;
-  function fromJS<JSValue>(
-    jsValue: JSValue,
-    reviver?: undefined
-  ): FromJS<JSValue>;
 
   type FromJS<JSValue> = JSValue extends FromJSNoTransform
     ? JSValue

diff --git a/type-definitions/ts-tests/from-js.ts b/type-definitions/ts-tests/from-js.ts
@@ -33,3 +33,17 @@ import { fromJS, List, Map } from 'immutable';
   // $ExpectType Map<"a", Map<"b", Map<"c", number>>>
   fromJS({a: {b: {c: 0}}});
 }
+
+{
+  // fromJS in an array of function
+
+  const create = [(data: any) => data, fromJS][1];
+
+  // $ExpectType any
+  create({ a: 'A' });
+
+  const createConst = ([(data: any) => data, fromJS] as const)[1];
+
+  // $ExpectType Map<"a", string>
+  createConst({ a: 'A' });
+}