fix(mongodb): expose authentication database

packages/app-tests/mongoConnectionOptions.test.ts

@@ -0,0 +1,29 @@
+import { strict as assert } from "node:assert";
+import test from "node:test";
+import {
+  mongoUrlParam,
+  setMongoUrlParam,
+  mongodbAuthFailureHint,
+} from "../../apps/desktop/src/lib/mongoConnectionOptions.ts";
+
+test("reads MongoDB authSource from URL params", () => {
+  assert.equal(mongoUrlParam("?replicaSet=rs0&authSource=admin", "authSource"), "admin");
+});
+
+test("sets MongoDB authSource while preserving other URL params", () => {
+  assert.equal(setMongoUrlParam("replicaSet=rs0", "authSource", "admin"), "replicaSet=rs0&authSource=admin");
+});
+
+test("removes empty MongoDB authSource from URL params", () => {
+  assert.equal(setMongoUrlParam("replicaSet=rs0&authSource=admin", "authSource", ""), "replicaSet=rs0");
+});
+
+test("adds a MongoDB authSource hint for legacy authentication failures", () => {
+  const message =
+    "Agent RPC error: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='rwuser', source='gray_lite_twin_fat'}";
+
+  assert.equal(
+    mongodbAuthFailureHint(message),
+    "Agent RPC error: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='rwuser', source='gray_lite_twin_fat'}\n\nCurrent authentication database: gray_lite_twin_fat. If this user was created in admin, set Authentication database to admin or add authSource=admin to URL params.",
+  );
+});