[IMP] web: userService: add hasGroup function

This commit adds the 'hasGroup' function to the user service. This
function holds a cache s.t. we never do twice an rpc for the same
group. This is the equivalent of 'user_has_group' in session, in
the legacy codebase.

addons/web/static/src/core/user_service.js

@@ -3,8 +3,11 @@
 import { registry } from "./registry";
 
 export const userService = {
-    start() {
+    dependencies: ["rpc"],
+    async: ["hasGroup"],
+    start(env, { rpc }) {
         const sessionInfo = odoo.session_info;
+        const groupProms = {};
 
         const context = {
             ...sessionInfo.user_context,
@@ -20,6 +23,20 @@ export const userService = {
             updateContext(update) {
                 Object.assign(context, update);
             },
+            hasGroup(group) {
+                if (!context.uid) {
+                    return Promise.resolve(false);
+                }
+                if (!groupProms[group]) {
+                    groupProms[group] = rpc("/web/dataset/call_kw/res.users/has_group", {
+                        model: "res.users",
+                        method: "has_group",
+                        args: [group],
+                        kwargs: { context },
+                    });
+                }
+                return groupProms[group];
+            },
             name: sessionInfo.name,
             userName: sessionInfo.username,
             isAdmin: sessionInfo.is_admin,

addons/web/static/tests/core/user_service_tests.js

@@ -0,0 +1,27 @@
+/** @odoo-module **/
+
+import { registry } from "@web/core/registry";
+import { userService } from "@web/core/user_service";
+import { makeTestEnv } from "../helpers/mock_env";
+
+const serviceRegistry = registry.category("services");
+
+QUnit.module("UserService");
+
+QUnit.test("successive calls to hasGroup", async (assert) => {
+    serviceRegistry.add("user", userService);
+    const groups = ["x"];
+    const mockRPC = (route, args) => {
+        assert.step(`${args.model}/${args.method}/${args.args[0]}`);
+        return groups.includes(args.args[0]);
+    };
+    const env = await makeTestEnv({ mockRPC });
+    let hasGroupX = await env.services.user.hasGroup("x");
+    let hasGroupY = await env.services.user.hasGroup("y");
+    assert.strictEqual(hasGroupX, true);
+    assert.strictEqual(hasGroupY, false);
+    let hasGroupXAgain = await env.services.user.hasGroup("x");
+    assert.strictEqual(hasGroupXAgain, true);
+
+    assert.verifySteps(["res.users/has_group/x", "res.users/has_group/y"]);
+});