From b245cbcc4a86359ca30cd8707a7bf4c3d4716836 Mon Sep 17 00:00:00 2001
From: Taesu <bytaesu@gmail.com>
Date: Fri, 16 Oct 2026 09:47:19 +0900
Subject: [PATCH] test(notion): verify stored image preservation

---
 .changeset/mellow-notion-owner.md             |  2 +-
 .../src/oauth2/link-account.test.ts           | 89 ++++++++++++++++++-
 2 files changed, 89 insertions(+), 2 deletions(-)

diff --git a/.changeset/mellow-notion-owner.md b/.changeset/mellow-notion-owner.md
index d448d5592d..37ec21a3bb 100644
--- a/.changeset/mellow-notion-owner.md
+++ b/.changeset/mellow-notion-owner.md
@@ -2,4 +2,4 @@
 "@better-auth/core": minor
 ---
 
-Allow partial Notion owner profiles and nullable display fields in `NotionProfile`, and leave the local image unset when no owner avatar is returned.
+Allow partial Notion owner profiles and nullable display fields in `NotionProfile`, and leave the local image unset when no owner avatar is returned. Existing user images are preserved when profile updates are enabled and the provider returns no image.
diff --git a/packages/better-auth/src/oauth2/link-account.test.ts b/packages/better-auth/src/oauth2/link-account.test.ts
index 3c43697ec6..9f2e2009c1 100644
--- a/packages/better-auth/src/oauth2/link-account.test.ts
+++ b/packages/better-auth/src/oauth2/link-account.test.ts
@@ -4,6 +4,7 @@ import type {
 	GoogleProfile,
 } from "@better-auth/core/social-providers";
 import { NodeSqliteDialect } from "@better-auth/kysely-adapter/node-sqlite-dialect";
+import { getTestInstance } from "better-auth/test";
 import { Kysely } from "kysely";
 import { HttpResponse, http } from "msw";
 import { setupServer } from "msw/node";
@@ -23,7 +24,6 @@ import { createAuthClient } from "../client";
 import { parseSetCookieHeader, setCookieToHeader } from "../cookies";
 import { signJWT } from "../crypto";
 import { getMigrations } from "../db/get-migration";
-import { getTestInstance } from "../test-utils/test-instance";
 import type { User } from "../types";
 import { DEFAULT_SECRET } from "../utils/constants";
 
@@ -2710,3 +2710,90 @@ describe("oauth2 - account-linking logs use the configured logger", async () =>
 		);
 	});
 });
+
+/**
+ * @see https://developers.notion.com/reference/user
+ * @see https://github.com/better-auth/better-auth/issues/8742
+ */
+it.each(["sign-in", "link"] as const)(
+	"preserves the stored image when Notion has no avatar during %s",
+	async (flow) => {
+		const storedImage = "https://example.com/stored-avatar.png";
+		const { auth, client, testUser, signInWithTestUser, cookieSetter } =
+			await getTestInstance(
+				{
+					socialProviders: {
+						notion: {
+							clientId: "notion-app",
+							clientSecret: "notion-secret",
+							overrideUserInfoOnSignIn: true,
+						},
+					},
+					account: {
+						accountLinking: {
+							trustedProviders: ["notion"],
+							updateUserInfoOnLink: true,
+						},
+					},
+				},
+				{ testUser: { image: storedImage } },
+			);
+		const { user, headers } = await signInWithTestUser();
+		const ctx = await auth.$context;
+		if (flow === "sign-in") {
+			await ctx.internalAdapter.createAccount({
+				userId: user.id,
+				providerId: "notion",
+				accountId: "notion-owner",
+			});
+		}
+		server.use(
+			http.post("https://api.notion.com/v1/oauth/token", () =>
+				HttpResponse.json({
+					access_token: "notion-token",
+					token_type: "bearer",
+				}),
+			),
+			http.get("https://api.notion.com/v1/users/me", () =>
+				HttpResponse.json({
+					bot: {
+						owner: {
+							user: {
+								object: "user",
+								id: "notion-owner",
+								type: "person",
+								name: "Notion User",
+								avatar_url: null,
+								person: { email: testUser.email },
+							},
+						},
+					},
+				}),
+			),
+		);
+		const request = { provider: "notion" as const, callbackURL: "/" };
+		const options = { headers, onSuccess: cookieSetter(headers) };
+		const response =
+			flow === "link"
+				? await client.linkSocial(request, options)
+				: await client.signIn.social(request, options);
+		expect(response.error).toBeNull();
+		const state = new URL(response.data!.url!).searchParams.get("state");
+		await client.$fetch("/callback/notion", {
+			query: { state, code: "notion-code" },
+			headers,
+			onError({ response }) {
+				expect(response.status).toBe(302);
+				expect(
+					new URL(
+						response.headers.get("location")!,
+						"http://localhost:3000",
+					).searchParams.get("error"),
+				).toBeNull();
+			},
+		});
+		const updated = await ctx.internalAdapter.findUserById(user.id);
+		expect(updated?.name).toBe("Notion User");
+		expect(updated?.image).toBe(storedImage);
+	},
+);