B2B-88: add starter kit structure and elements

packages/supabase/src/require-user.ts

@@ -0,0 +1,69 @@
+import type { SupabaseClient, User } from '@supabase/supabase-js';
+
+import { checkRequiresMultiFactorAuthentication } from './check-requires-mfa';
+
+const MULTI_FACTOR_AUTH_VERIFY_PATH = '/auth/verify';
+const SIGN_IN_PATH = '/auth/sign-in';
+
+/**
+ * @name requireUser
+ * @description Require a session to be present in the request
+ * @param client
+ */
+export async function requireUser(client: SupabaseClient): Promise<
+  | {
+      error: null;
+      data: User;
+    }
+  | (
+      | {
+          error: AuthenticationError;
+          data: null;
+          redirectTo: string;
+        }
+      | {
+          error: MultiFactorAuthError;
+          data: null;
+          redirectTo: string;
+        }
+    )
+> {
+  const { data, error } = await client.auth.getUser();
+
+  if (!data.user || error) {
+    return {
+      data: null,
+      error: new AuthenticationError(),
+      redirectTo: SIGN_IN_PATH,
+    };
+  }
+
+  const requiresMfa = await checkRequiresMultiFactorAuthentication(client);
+
+  // If the user requires multi-factor authentication,
+  // redirect them to the page where they can verify their identity.
+  if (requiresMfa) {
+    return {
+      data: null,
+      error: new MultiFactorAuthError(),
+      redirectTo: MULTI_FACTOR_AUTH_VERIFY_PATH,
+    };
+  }
+
+  return {
+    error: null,
+    data: data.user,
+  };
+}
+
+class AuthenticationError extends Error {
+  constructor() {
+    super(`Authentication required`);
+  }
+}
+
+class MultiFactorAuthError extends Error {
+  constructor() {
+    super(`Multi-factor authentication required`);
+  }
+}