fix: add missing `Object.groupBy()` and `Map.groupBy()` types (#21050)

4 files changed, 81 insertions, 0 deletions

diff --git a/cli/build.rs b/cli/build.rs
index b7a452465..16b31081e 100644
--- a/cli/build.rs
+++ b/cli/build.rs
@@ -251,6 +251,7 @@ mod ts {
       "esnext.decorators",
       "esnext.disposable",
       "esnext.intl",
+      "esnext.object",
     ];
 
     let path_dts = cwd.join("tsc/dts");
diff --git a/cli/tests/unit/globals_test.ts b/cli/tests/unit/globals_test.ts
index b47e83cfd..9f7f77644 100644
--- a/cli/tests/unit/globals_test.ts
+++ b/cli/tests/unit/globals_test.ts
@@ -170,3 +170,50 @@ Deno.test(async function arrayFromAsync() {
   const b = await Array.fromAsync(new Map([[1, 2], [3, 4]]));
   assertEquals(b, [[1, 2], [3, 4]]);
 });
+
+// Taken from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/groupBy#examples
+Deno.test(function objectGroupBy() {
+  const inventory = [
+    { name: "asparagus", type: "vegetables", quantity: 5 },
+    { name: "bananas", type: "fruit", quantity: 0 },
+    { name: "goat", type: "meat", quantity: 23 },
+    { name: "cherries", type: "fruit", quantity: 5 },
+    { name: "fish", type: "meat", quantity: 22 },
+  ];
+  const result = Object.groupBy(inventory, ({ type }) => type);
+  assertEquals(result, {
+    vegetables: [
+      { name: "asparagus", type: "vegetables", quantity: 5 },
+    ],
+    fruit: [
+      { name: "bananas", type: "fruit", quantity: 0 },
+      { name: "cherries", type: "fruit", quantity: 5 },
+    ],
+    meat: [
+      { name: "goat", type: "meat", quantity: 23 },
+      { name: "fish", type: "meat", quantity: 22 },
+    ],
+  });
+});
+
+// Taken from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/groupBy#examples
+Deno.test(function mapGroupBy() {
+  const inventory = [
+    { name: "asparagus", type: "vegetables", quantity: 9 },
+    { name: "bananas", type: "fruit", quantity: 5 },
+    { name: "goat", type: "meat", quantity: 23 },
+    { name: "cherries", type: "fruit", quantity: 12 },
+    { name: "fish", type: "meat", quantity: 22 },
+  ];
+  const restock = { restock: true };
+  const sufficient = { restock: false };
+  const result = Map.groupBy(
+    inventory,
+    ({ quantity }) => quantity < 6 ? restock : sufficient,
+  );
+  assertEquals(result.get(restock), [{
+    name: "bananas",
+    type: "fruit",
+    quantity: 5,
+  }]);
+});
diff --git a/cli/tsc/dts/lib.esnext.d.ts b/cli/tsc/dts/lib.esnext.d.ts
index 3df5bce09..0f265acfa 100644
--- a/cli/tsc/dts/lib.esnext.d.ts
+++ b/cli/tsc/dts/lib.esnext.d.ts
@@ -19,5 +19,6 @@ and limitations under the License.
 /// <reference lib="es2023" />
 /// <reference lib="esnext.array" />
 /// <reference lib="esnext.intl" />
+/// <reference lib="esnext.object" />
 /// <reference lib="esnext.decorators" />
 /// <reference lib="esnext.disposable" />
diff --git a/cli/tsc/dts/lib.esnext.object.d.ts b/cli/tsc/dts/lib.esnext.object.d.ts
new file mode 100644
index 000000000..130f2fc9f
--- /dev/null
+++ b/cli/tsc/dts/lib.esnext.object.d.ts
@@ -0,0 +1,32 @@
+/*! *****************************************************************************
+Copyright (c) Microsoft Corporation. All rights reserved.
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+this file except in compliance with the License. You may obtain a copy of the
+License at http://www.apache.org/licenses/LICENSE-2.0
+
+THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
+MERCHANTABLITY OR NON-INFRINGEMENT.
+
+See the Apache Version 2.0 License for specific language governing permissions
+and limitations under the License.
+***************************************************************************** */
+
+/// <reference no-default-lib="true"/>
+
+// NOTE(iuioiua): taken from https://github.com/microsoft/TypeScript/issues/47171#issuecomment-1697373352
+// while we wait for these types to officially ship
+interface ObjectConstructor {
+  groupBy<Item, Key extends PropertyKey>(
+    items: Iterable<Item>,
+    keySelector: (item: Item, index: number) => Key,
+  ): Record<Key, Item[]>;
+}
+
+interface MapConstructor {
+  groupBy<Item, Key>(
+    items: Iterable<Item>,
+    keySelector: (item: Item, index: number) => Key,
+  ): Map<Key, Item[]>;
+}