handler: createAuthMiddleware()

in packages/better-auth/src/plugins/anonymous/index.ts [184:235]
38 lines of code
9 McCabe index (conditional complexity)

					handler: createAuthMiddleware(async (ctx) => {
						const setCookie = ctx.context.responseHeaders?.get("set-cookie");

						/**
						 * We can consider the user is about to sign in or sign up
						 * if the response contains a session token.
						 */
						const sessionTokenName = ctx.context.authCookies.sessionToken.name;
						/**
						 * The user is about to link their account.
						 */
						const sessionCookie = parseSetCookieHeader(setCookie || "")
							.get(sessionTokenName)
							?.value.split(".")[0];

						if (!sessionCookie) {
							return;
						}
						/**
						 * Make sure the user had an anonymous session.
						 */
						const session = await getSessionFromCtx<{ isAnonymous: boolean }>(
							ctx,
							{
								disableRefresh: true,
							},
						);

						if (!session || !session.user.isAnonymous) {
							return;
						}

						if (ctx.path === "/sign-in/anonymous") {
							throw new APIError("BAD_REQUEST", {
								message:
									ERROR_CODES.ANONYMOUS_USERS_CANNOT_SIGN_IN_AGAIN_ANONYMOUSLY,
							});
						}
						const newSession = ctx.context.newSession;
						if (!newSession) {
							return;
						}
						if (options?.onLinkAccount) {
							await options?.onLinkAccount?.({
								anonymousUser: session,
								newUser: newSession,
							});
						}
						if (!options?.disableDeleteAnonymousUser) {
							await ctx.context.internalAdapter.deleteUser(session.user.id);
						}
					}),