[FIX] web: limit fetched records when grouping

**Issue:**

- Open a list view with `expand="1"` and `limit=<arbitrary small number, say 5>`.
- BUG: The pager shows that it's displaying the limited records, but in reality,
  it's displaying all records under each group.

**Solution:**

This is because we are *not* limiting the number of records being fetch in the first
read_group rpc. We are now specifying the expand_limit in this commit.

closes odoo/odoo#106238

X-original-commit: e5bba9f5eb63ee95924c892801fe18feaef6d1fc
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>
Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>

addons/web/static/src/views/relational_model.js

@@ -2399,6 +2399,7 @@ export class DynamicGroupList extends DynamicList {
                 lazy: true,
                 expand: this.expand,
                 expand_orderby: this.expand ? orderByToString(this.orderBy) : null,
+                expand_limit: this.expand ? this.limitByGroup : null,
                 offset: this.offset,
                 limit: this.limit,
                 context: this.context,

addons/web/static/tests/views/list_view_tests.js

@@ -12,7 +12,7 @@ import { session } from "@web/session";
 import { FloatField } from "@web/views/fields/float/float_field";
 import { TextField } from "@web/views/fields/text/text_field";
 import { ListController } from "@web/views/list/list_controller";
-import { DynamicRecordList } from "@web/views/relational_model";
+import { DynamicRecordList, DynamicGroupList } from "@web/views/relational_model";
 import { actionService } from "@web/webclient/actions/action_service";
 import { makeFakeLocalizationService, makeFakeUserService } from "../helpers/mock_services";
 import { Many2XAutocomplete } from "@web/views/fields/relational_utils";
@@ -5377,6 +5377,35 @@ QUnit.module("Views", (hooks) => {
         }
     );
 
+    QUnit.test(
+        "grouped, show only limited records when the list view is initially expanded",
+        async function (assert) {
+            const forcedDefaultLimit = 3;
+            patchWithCleanup(DynamicGroupList, { DEFAULT_LIMIT: forcedDefaultLimit });
+
+            serverData.models.foo.records = [
+                { id: 121, foo: "blip" },
+                { id: 122, foo: "blip" },
+                { id: 123, foo: "blip" },
+                { id: 124, foo: "blip" },
+                { id: 125, foo: "blip" },
+                { id: 126, foo: "blip" },
+            ];
+            await makeView({
+                type: "list",
+                resModel: "foo",
+                serverData,
+                arch: /*xml*/ `
+                    <tree expand="1">
+                        <field name="foo"/>
+                    </tree>`,
+                groupBy: ["foo"],
+            });
+
+            assert.containsN(target, ".o_data_row", forcedDefaultLimit);
+        }
+    );
+
     QUnit.test("list keeps offset on switchView", async (assert) => {
         assert.expect(3);
         serverData.views = {

addons/web/static/tests/views/view_dialogs/select_create_dialog_tests.js

@@ -127,6 +127,7 @@ QUnit.module("ViewDialogs", (hooks) => {
                             orderby: "",
                             expand: false,
                             expand_orderby: null,
+                            expand_limit: null,
                             lazy: true,
                             limit: 80,
                             offset: 0,