refactor: return linked account in findOAuthUser (#7331)

Co-authored-by: Maxwell <145994855+ping-maxwell@users.noreply.github.com>

packages/better-auth/src/db/internal-adapter.ts

@@ -721,26 +721,29 @@ export const createInternalAdapter = (
 			providerId: string,
 		) => {
 			// we need to find account first to avoid missing user if the email changed with the provider for the same account
-			const account = await (await getCurrentAdapter(adapter))
-				.findMany<Account & { user: User | null }>({
-					model: "account",
-					where: [
-						{
-							value: accountId,
-							field: "accountId",
-						},
-					],
-					join: {
-						user: true,
+			const account = await (await getCurrentAdapter(adapter)).findOne<
+				Account & { user: User | null }
+			>({
+				model: "account",
+				where: [
+					{
+						value: accountId,
+						field: "accountId",
 					},
-				})
-				.then((accounts) => {
-					return accounts.find((a) => a.providerId === providerId);
-				});
+					{
+						value: providerId,
+						field: "providerId",
+					},
+				],
+				join: {
+					user: true,
+				},
+			});
 			if (account) {
 				if (account.user) {
 					return {
 						user: account.user,
+						linkedAccount: account,
 						accounts: [account],
 					};
 				} else {
@@ -756,6 +759,7 @@ export const createInternalAdapter = (
 					if (user) {
 						return {
 							user,
+							linkedAccount: account,
 							accounts: [account],
 						};
 					}
@@ -785,6 +789,7 @@ export const createInternalAdapter = (
 					});
 					return {
 						user,
+						linkedAccount: null,
 						accounts: accounts || [],
 					};
 				} else {

packages/better-auth/src/oauth2/link-account.ts

@@ -37,12 +37,14 @@ export async function handleOAuthUserInfo(
 	const isRegister = !user;
 
 	if (dbUser) {
-		const hasBeenLinked = dbUser.accounts.find(
-			(a) =>
-				a.providerId === account.providerId &&
-				a.accountId === account.accountId,
-		);
-		if (!hasBeenLinked) {
+		const linkedAccount =
+			dbUser.linkedAccount ??
+			dbUser.accounts.find(
+				(acc) =>
+					acc.providerId === account.providerId &&
+					acc.accountId === account.accountId,
+			);
+		if (!linkedAccount) {
 			const trustedProviders =
 				c.context.options.account?.accountLinking?.trustedProviders;
 			const isTrustedProvider =
@@ -111,14 +113,14 @@ export async function handleOAuthUserInfo(
 
 			if (c.context.options.account?.storeAccountCookie) {
 				await setAccountCookie(c, {
-					...hasBeenLinked,
+					...linkedAccount,
 					...freshTokens,
 				});
 			}
 
 			if (Object.keys(freshTokens).length > 0) {
 				await c.context.internalAdapter.updateAccount(
-					hasBeenLinked.id,
+					linkedAccount.id,
 					freshTokens,
 				);
 			}

packages/core/src/types/context.ts

@@ -91,7 +91,11 @@ export interface InternalAdapter<
 		email: string,
 		accountId: string,
 		providerId: string,
-	): Promise<{ user: User; accounts: Account[] } | null>;
+	): Promise<{
+		user: User;
+		linkedAccount: Account | null;
+		accounts: Account[];
+	} | null>;
 
 	findUserByEmail(
 		email: string,