refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider (#1223)

* refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider

* test: adjusting tests for adapter and events

* docs: add comments for unknown auth provider

* fix: missing dayjs import

packages/auth/test/adapter.spec.ts

@@ -0,0 +1,67 @@
+import { describe, expect, test } from "vitest";
+
+import { users } from "@homarr/db/schema/sqlite";
+import { createDb } from "@homarr/db/test";
+
+import { createAdapter } from "../adapter";
+
+describe("createAdapter should create drizzle adapter", () => {
+  test.each([["credentials" as const], ["ldap" as const], ["oidc" as const]])(
+    "createAdapter getUserByEmail should return user for provider %s when this provider provided",
+    async (provider) => {
+      // Arrange
+      const db = createDb();
+      const adapter = createAdapter(db, provider);
+      const email = "test@example.com";
+      await db.insert(users).values({ id: "1", name: "test", email, provider });
+
+      // Act
+      const user = await adapter.getUserByEmail?.(email);
+
+      // Assert
+      expect(user).toEqual({
+        id: "1",
+        name: "test",
+        email,
+        emailVerified: null,
+        image: null,
+      });
+    },
+  );
+
+  test.each([
+    ["credentials", ["ldap", "oidc"]],
+    ["ldap", ["credentials", "oidc"]],
+    ["oidc", ["credentials", "ldap"]],
+  ] as const)(
+    "createAdapter getUserByEmail should return null if only for other providers than %s exist",
+    async (requestedProvider, existingProviders) => {
+      // Arrange
+      const db = createDb();
+      const adapter = createAdapter(db, requestedProvider);
+      const email = "test@example.com";
+      for (const provider of existingProviders) {
+        await db.insert(users).values({ id: provider, name: `test-${provider}`, email, provider });
+      }
+
+      // Act
+      const user = await adapter.getUserByEmail?.(email);
+
+      // Assert
+      expect(user).toBeNull();
+    },
+  );
+
+  test("createAdapter getUserByEmail should throw error if provider is unknown", async () => {
+    // Arrange
+    const db = createDb();
+    const adapter = createAdapter(db, "unknown");
+    const email = "test@example.com";
+
+    // Act
+    const actAsync = async () => await adapter.getUserByEmail?.(email);
+
+    // Assert
+    await expect(actAsync()).rejects.toThrow("Unable to get user by email for unknown provider");
+  });
+});