Add Discord account linking from settings page

Adds a "Connect Discord" button in the Account settings section that
triggers BetterAuth's linkSocial flow to attach a Discord account to
an existing user without requiring a sign-out/sign-in. After the OAuth
callback, the ?section= URL param returns the user to the Account tab.
The Notifications toggle was already gated on Discord being linked.

https://claude.ai/code/session_01UerTpTuBWjreTNEns8srkp

app/components/user/settings/AccountSection.tsx

@@ -1,5 +1,8 @@
+import { useState } from "react";
 import { Link } from "react-router";
 import { Badge } from "~/components/ui/badge";
+import { Button } from "~/components/ui/button";
+import { authClient } from "~/lib/auth-client";
 
 type LinkedAccount = {
   id: string;
@@ -18,8 +21,15 @@ const PROVIDER_LABELS: Record<string, string> = {
 };
 
 export function AccountSection({ email, linkedAccounts }: Props) {
+  const [linkingDiscord, setLinkingDiscord] = useState(false);
   const hasPassword = linkedAccounts.some((a) => a.providerId === "credential");
   const oauthAccounts = linkedAccounts.filter((a) => a.providerId !== "credential");
+  const hasDiscord = linkedAccounts.some((a) => a.providerId === "discord");
+
+  async function handleConnectDiscord() {
+    setLinkingDiscord(true);
+    await authClient.linkSocial({ provider: "discord", callbackURL: "/settings?section=account" });
+  }
 
   return (
     <div className="space-y-6">
@@ -57,6 +67,16 @@ export function AccountSection({ email, linkedAccounts }: Props) {
               <p className="text-sm text-muted-foreground">No sign-in methods found.</p>
             )}
           </div>
+          {!hasDiscord && (
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={handleConnectDiscord}
+              disabled={linkingDiscord}
+            >
+              {linkingDiscord ? "Redirecting…" : "Connect Discord"}
+            </Button>
+          )}
         </div>
 
         {hasPassword && (

app/components/user/settings/__tests__/AccountSection.test.tsx

@@ -0,0 +1,60 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { AccountSection } from "../AccountSection";
+
+vi.mock("react-router", () => ({
+  Link: ({ children, to }: { children: React.ReactNode; to: string }) => (
+    <a href={to}>{children}</a>
+  ),
+}));
+
+const mockLinkSocial = vi.fn();
+vi.mock("~/lib/auth-client", () => ({
+  authClient: {
+    linkSocial: (...args: unknown[]) => mockLinkSocial(...args),
+  },
+}));
+
+describe("AccountSection", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockLinkSocial.mockResolvedValue({});
+  });
+
+  it("shows Connect Discord button when Discord is not linked", () => {
+    render(
+      <AccountSection
+        email="user@example.com"
+        linkedAccounts={[{ id: "1", providerId: "credential" }]}
+      />
+    );
+    expect(screen.getByRole("button", { name: /connect discord/i })).toBeInTheDocument();
+  });
+
+  it("does not show Connect Discord button when Discord is already linked", () => {
+    render(
+      <AccountSection
+        email="user@example.com"
+        linkedAccounts={[
+          { id: "1", providerId: "credential" },
+          { id: "2", providerId: "discord" },
+        ]}
+      />
+    );
+    expect(screen.queryByRole("button", { name: /connect discord/i })).not.toBeInTheDocument();
+  });
+
+  it("calls authClient.linkSocial with discord provider on button click", () => {
+    render(
+      <AccountSection
+        email="user@example.com"
+        linkedAccounts={[{ id: "1", providerId: "credential" }]}
+      />
+    );
+    fireEvent.click(screen.getByRole("button", { name: /connect discord/i }));
+    expect(mockLinkSocial).toHaveBeenCalledWith({
+      provider: "discord",
+      callbackURL: "/settings?section=account",
+    });
+  });
+});

app/routes/settings.tsx

@@ -1,4 +1,4 @@
-import { redirect } from "react-router";
+import { redirect, useSearchParams } from "react-router";
 import { useState } from "react";
 import { Bell, Key, Lock, Shield, User } from "lucide-react";
 import { auth } from "~/lib/auth.server";
@@ -206,7 +206,11 @@ export async function action(args: Route.ActionArgs): Promise<ActionData | Respo
 
 export default function SettingsPage({ loaderData, actionData }: Route.ComponentProps) {
   const { user, isInActiveDraft, linkedAccounts, dataRequestCooldownUntil } = loaderData;
-  const [activeSection, setActiveSection] = useState<SectionId>("profile");
+  const [searchParams] = useSearchParams();
+  const VALID_SECTION_IDS = new Set<SectionId>(["profile", "account", "notifications", "api", "privacy"]);
+  const sectionParam = searchParams.get("section") as SectionId | null;
+  const initialSection: SectionId = sectionParam && VALID_SECTION_IDS.has(sectionParam) ? sectionParam : "profile";
+  const [activeSection, setActiveSection] = useState<SectionId>(initialSection);
   const [mobileView, setMobileView] = useState<"grid" | "section">("grid");
 
   const handleSectionChange = (id: string, mobile = false) => {