Merge pull request #27936 from overleaf/em-unit-tests-mongo

Make Mongo available to unit tests in all services

GitOrigin-RevId: b65bbb69883d5bba31d09802b89f35bdc523fe4d

libraries/mongo-utils/test-utils.js

@@ -0,0 +1,55 @@
+// @ts-check
+
+/**
+ * @import { MongoClient } from 'mongodb'
+ * @import { MongoClient as LegacyMongoClient } from 'mongodb-legacy'
+ */
+
+/**
+ * Delete all data from the test Mongo database
+ *
+ * This doesn't drop the collections, so indexes are preserved.
+ *
+ * @param {MongoClient | LegacyMongoClient} mongoClient
+ */
+async function cleanupTestDatabase(mongoClient) {
+  ensureTestDatabase(mongoClient)
+  const db = mongoClient.db()
+  const allCollections = await db.collections()
+  const collections = allCollections.filter(
+    coll => coll.collectionName !== 'migrations'
+  )
+  await Promise.all(collections.map(coll => coll.deleteMany({})))
+}
+
+/**
+ * Drop the test Monto database
+ *
+ * This drops the whole database, including indexes.
+ *
+ * @param {MongoClient | LegacyMongoClient } mongoClient
+ */
+async function dropTestDatabase(mongoClient) {
+  ensureTestDatabase(mongoClient)
+  await mongoClient.db().dropDatabase()
+}
+/**
+ * Ensure that the given client is connected to a test database.
+ *
+ * This should be called before performing destructive operations on the test
+ * database.
+ *
+ * @param {MongoClient | LegacyMongoClient } mongoClient
+ */
+function ensureTestDatabase(mongoClient) {
+  const dbName = mongoClient.db().databaseName
+  const env = process.env.NODE_ENV
+
+  if (dbName !== 'test-overleaf' || env !== 'test') {
+    throw new Error(
+      `Refusing to clear database '${dbName}' in environment '${env}'`
+    )
+  }
+}
+
+module.exports = { cleanupTestDatabase, dropTestDatabase }