fix: handle serial and false cases in generateId (#7474)

packages/better-auth/src/context/create-context.test.ts

@@ -566,6 +566,45 @@ describe("base context creation", () => {
 				expect(id.length).toBeGreaterThan(0);
 			}
 		});
+
+		it("should return uuid when generateId is 'uuid'", async () => {
+			const res = await initBase({
+				advanced: {
+					database: {
+						generateId: "uuid",
+					},
+				},
+			});
+			const id = res.generateId({ model: "user" });
+			expect(typeof id).toBe("string");
+			expect(id).toMatch(
+				/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i,
+			);
+		});
+
+		it("should return false when generateId is 'serial'", async () => {
+			const res = await initBase({
+				advanced: {
+					database: {
+						generateId: "serial",
+					},
+				},
+			});
+			const id = res.generateId({ model: "user" });
+			expect(id).toBe(false);
+		});
+
+		it("should return false when generateId is false", async () => {
+			const res = await initBase({
+				advanced: {
+					database: {
+						generateId: false,
+					},
+				},
+			});
+			const id = res.generateId({ model: "user" });
+			expect(id).toBe(false);
+		});
 	});
 
 	describe("password configuration", () => {

packages/better-auth/src/context/create-context.ts

@@ -159,8 +159,15 @@ export async function createAuthContext(
 		if (typeof (options.advanced as any)?.generateId === "function") {
 			return (options.advanced as any).generateId({ model, size });
 		}
-		if (typeof options?.advanced?.database?.generateId === "function") {
-			return options.advanced.database.generateId({ model, size });
+		const dbGenerateId = options?.advanced?.database?.generateId;
+		if (typeof dbGenerateId === "function") {
+			return dbGenerateId({ model, size });
+		}
+		if (dbGenerateId === "uuid") {
+			return crypto.randomUUID();
+		}
+		if (dbGenerateId === "serial" || dbGenerateId === false) {
+			return false;
 		}
 		return generateId(size);
 	};

packages/better-auth/src/plugins/api-key/routes/create-api-key.ts

@@ -444,10 +444,10 @@ export function createApiKey({
 				});
 				await setApiKey(ctx, apiKey, opts);
 			} else if (opts.storage === "secondary-storage") {
-				const id =
-					ctx.context.generateId({
-						model: API_KEY_TABLE_NAME,
-					}) ?? generateId();
+				const generatedId = ctx.context.generateId({
+					model: API_KEY_TABLE_NAME,
+				});
+				const id = generatedId || generateId();
 				apiKey = {
 					...data,
 					id,