Add test script for bypassing backend authentication issue

.github/workflows/js.yml

@@ -74,14 +74,15 @@ jobs:
           --proxy-addr=127.0.0.1:47017
           --mode=diff-normal
           --handler=pg
-          --postgresql-url='postgres://username@127.0.0.1:5432/ferretdb'
+          --postgresql-url='postgres://127.0.0.1:5433/ferretdb'
+          --test-enable-new-auth=true
           2> ferretdb.log &
 
       - name: Run testjs for MongoDB
         run: bin/task testjs TESTJS_PORT=47017
 
       - name: Run testjs for FerretDB
-        run: bin/task testjs
+        run: bin/task testjs-auth
 
       - name: Compress FerretDB log before upload
         if: failure()

Taskfile.yml

@@ -553,6 +553,14 @@ tasks:
         'mongodb://host.docker.internal:{{.TESTJS_PORT}}/'
         /legacy-mongo-shell/test.js
 
+  testjs-auth:
+    desc: "Run legacy MongoDB shell (`mongo`) with test.js script using PLAIN authentication mechanism"
+    cmds:
+      - >
+        docker compose run --rm legacy-mongo-shell
+        'mongodb://username:password@host.docker.internal:{{.TESTJS_PORT}}/?authMechanism=PLAIN'
+        /legacy-mongo-shell/test.js
+
   docker-init:
     run: once
     cmds:

build/legacy-mongo-shell/test.js

@@ -3,5 +3,30 @@
 (function() {
   'use strict';
 
+  let port = 27017;
+
+  let roles = [];
+
+  if (db.getSiblingDB('admin').runCommand({getParameter: '*'}).wiredTigerConcurrentReadTransactions !== undefined) {
+    roles.push({role: 'read', db: 'admin'});
+    port = 47017;
+  };
+
+  db.getSiblingDB('admin').system.users.remove({});
+
+  db.getSiblingDB('admin').createUser({user: 'username', pwd: 'password', roles: roles});
+
+  const mongoClient = function(uri) {
+    return new Mongo(uri);
+  }
+
+  const uri = 'mongodb://username:password@host.docker.internal:' + port + '/?authMechanism=SCRAM-SHA-1';
+
+  try {
+    mongoClient(uri);
+  } catch (e) {
+    throw new Error('test.js failed: ' + e);
+  }
+
   print('test.js passed!');
 })();