Fix Generator.asIteratorObject signature

Author: cknitt

packages/@rescript/runtime/Stdlib_Generator.res

@@ -6,7 +6,7 @@ external asIterable: t<'yield, 'return, 'next> => Stdlib_Iterable.t<'yield> = "%
 external asIteratorObject: t<'yield, 'return, 'next> => Stdlib_IteratorObject.t<
   'yield,
   'return,
-  unknown,
+  'next,
 > = "%identity"
 
 @send

packages/@rescript/runtime/Stdlib_Generator.resi

@@ -29,7 +29,7 @@ external asIterable: t<'yield, 'return, 'next> => Stdlib_Iterable.t<'yield> = "%
 external asIteratorObject: t<'yield, 'return, 'next> => Stdlib_IteratorObject.t<
   'yield,
   'return,
-  unknown,
+  'next,
 > = "%identity"
 
 /**

tests/tests/src/stdlib/Stdlib_IteratorTests.mjs

@@ -362,6 +362,29 @@ Test.run([
   4
 ]);
 
+Test.run([
+  [
+    "Stdlib_IteratorTests.res",
+    258,
+    13,
+    51
+  ],
+  "Generator.asIteratorObject nextValue"
+], (generatorWithNext => {
+      let match = generatorWithNext.next();
+      if (match.done !== false) {
+        return;
+      }
+      let match$1 = generatorWithNext.next(41);
+      if (match$1.done !== false || match$1.value !== 42) {
+        return;
+      }
+      return "nextValue";
+    })((function* () {
+        let injected = yield 1;
+        yield injected + 1 | 0;
+      })()), eq, "nextValue");
+
 let generatorReturnValueResult = {
   contents: undefined
 };

tests/tests/src/stdlib/Stdlib_IteratorTests.res

@@ -255,6 +255,27 @@ Test.run(
   [2, 4],
 )
 
+Test.run(
+  __POS_OF__("Generator.asIteratorObject nextValue"),
+  {
+    let generatorWithNext: Generator.t<int, unit, int> = %raw(`(function* () {
+      let injected = yield 1
+      yield injected + 1
+    })()`)
+
+    switch generatorWithNext->Generator.next {
+    | Yield({value: 1}) =>
+      switch generatorWithNext->Generator.asIteratorObject->IteratorObject.nextValue(41) {
+      | Yield({value: 42}) => Some("nextValue")
+      | _ => None
+      }
+    | _ => None
+    }
+  },
+  eq,
+  Some("nextValue"),
+)
+
 let generatorReturnValueResult = ref(None)
 let generatorReturnValue: Generator.t<int, string, unit> = %raw(`(function* () {
   yield 1