chore: update Pipeline execution to accept options for index mode

Author: SelaseKay

packages/cloud_firestore/cloud_firestore_web/lib/cloud_firestore_web.dart

@@ -303,7 +303,11 @@ class FirebaseFirestoreWeb extends FirebaseFirestorePlatform {
 
     final dartPipeline = firestore_interop.Pipeline.getInstance(jsPipeline);
     return convertWebExceptions(() async {
-      final snapshot = await dartPipeline.execute();
+      String? executeOptions;
+      if (options != null) {
+        executeOptions = options['indexMode'] as String;
+      }
+      final snapshot = await dartPipeline.execute(executeOptions);
 
       final results = snapshot.results
           .map((r) => PipelineResultWeb(this, _delegate, r.jsObject))

packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore.dart

@@ -1183,9 +1183,14 @@ class Pipeline extends JsObjectWrapper<firestore_interop.PipelineJsImpl> {
       : super.fromJsObject(jsObject);
 
   /// Runs this pipeline using the global JS SDK execute function.
-  Future<PipelineSnapshot> execute() async {
+  Future<PipelineSnapshot> execute(String? executeOptions) async {
+    final executeOptionsJs = firestore_interop.PipelineExecuteOptionsJsImpl();
+    if (executeOptions != null) {
+      executeOptionsJs.indexMode = executeOptions.toJS;
+    }
+    executeOptionsJs.pipeline = jsObject as JSAny;
     final snapshot =
-        await firestore_interop.pipelines.execute(jsObject as JSAny).toDart;
+        await firestore_interop.pipelines.execute(executeOptionsJs).toDart;
     return PipelineSnapshot.getInstance(snapshot);
   }
 }

packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore_interop.dart

@@ -348,7 +348,8 @@ external PipelinesJsImpl get pipelines;
 /// Pipeline expression API — mirrors the Firebase JS SDK pipelines module.
 /// Use these to build expressions for where(), sort(), addFields(), aggregate(), etc.
 extension type PipelinesJsImpl._(JSObject _) implements JSObject {
-  external JSPromise<PipelineSnapshotJsImpl> execute(JSAny pipeline);
+  external JSPromise<PipelineSnapshotJsImpl> execute(
+      PipelineExecuteOptionsJsImpl pipeline);
 
   // --- Expression builders ---
   external ExpressionJsImpl field(JSString path);
@@ -1186,8 +1187,6 @@ extension type PipelineSourceJsImpl._(JSObject _) implements JSObject {
 /// Pipeline returned by PipelineSource methods; chain stages and call execute().
 /// See: https://firebase.google.com/docs/reference/js/firestore_pipelines.pipeline
 extension type PipelineJsImpl._(JSObject _) implements JSObject {
-  external JSPromise<PipelineSnapshotJsImpl> execute(
-      [PipelineExecuteOptions? options]);
   external PipelineJsImpl limit(JSNumber limit);
   external PipelineJsImpl offset(JSNumber offset);
   external PipelineJsImpl where(JSAny condition);
@@ -1297,3 +1296,12 @@ extension type FindNearestStageOptionsJsImpl._(JSObject _) implements JSObject {
   // ignore: avoid_setters_without_getters
   external set distanceField(JSString value);
 }
+
+extension type PipelineExecuteOptionsJsImpl._(JSObject _) implements JSObject {
+  PipelineExecuteOptionsJsImpl() : this._(JSObject.new());
+
+  // ignore: avoid_setters_without_getters
+  external set indexMode(JSString value);
+  // ignore: avoid_setters_without_getters
+  external set pipeline(JSAny value);
+}