feat(MongoMemoryServer): use storage engine "wiredTiger" if version is 7.0.0 or higher

fixes #742

Author: hasezoey

README.md

@@ -122,7 +122,7 @@ const mongod = new MongoMemoryServer({
     ip?: string, // by default '127.0.0.1', for binding to all IP addresses set it to `::,0.0.0.0`,
     dbName?: string, // by default '' (empty string)
     dbPath?: string, // by default create in temp directory
-    storageEngine?: string, // by default `ephemeralForTest`, available engines: [ 'ephemeralForTest', 'wiredTiger' ]
+    storageEngine?: string, // by default `ephemeralForTest`(unless mongodb 7.0.0, where its `wiredTiger`), available engines: [ 'ephemeralForTest', 'wiredTiger' ]
     replSet?: string, // by default no replica set, replica set name
     args?: string[], // by default no additional arguments, any additional command line arguments for `mongod` `mongod` (ex. ['--notablescan'])
   },

docs/api/interfaces/mongo-memory-instance-opts.md

@@ -72,7 +72,7 @@ This option will automatically be set with a directory generated by [`mkdtemp`](
 ### storageEngine
 
 Typings: `storageEngine?: StorageEngine`  
-Default: `ephemeralForTest`
+Default: `ephemeralForTest` (unless mongodb version is `7.0.0`, where its `wiredTiger`)
 
 Set which storage engine to use, uses [`StorageEngine`](#helper-type-storageengine).
 
@@ -98,4 +98,6 @@ Custom Explanation:
 MongoDB has stated that storage-engine `ephemeralForTest` is unstable and has been deprecated, it will be removed with mongodb 7.
 
 In MMS there has been no observation of `ephemeralForTest` being unstable (aside from some missing features) and will continue to be the default until mongodb-memory-server changes to a version where `ephemeralForTest` is not present anymore.
+
+With mongodb-memory-server 9.0.0, if mongodb 7.0.0 or higher is used, `wiredTiger` is the default engine.
 :::

docs/api/interfaces/replset-opts.md

@@ -66,7 +66,7 @@ Also see [`MongoMemoryInstanceOpts.spawn`](./mongo-memory-instance-opts.md#spawn
 ### storageEngine
 
 Typings: `storageEngine?: StorageEngine`  
-Default: `"ephemeralForTest"`
+Default: `"ephemeralForTest"` (unless mongodb version is `7.0.0`, where its `wiredTiger`)
 
 Set which Storage Engine to use, uses [`StorageEngine`](./mongo-memory-instance-opts.md#helper-type-storageengine).
 

docs/guides/migration/migrate9.md

@@ -109,3 +109,10 @@ This *should* help with non-closed instances not exiting the nodejs process.
 Previously MMS used `get-port`, but it caused some big memory-leakage across big projects, so it has been replaced with one that uses less maps.
 
 It also has been replaced because newer versions were ESM only, but we couldnt switch to ESM yet (and using ESM in CommonJS is not a great experience)
+
+## Mongodb version 7.0.0 is now supported
+
+Mongob version `7.0.0` removed storage engine `ephemeralForTest`, with mongodb-memory-server 9.0.0 storage engine `wiredTiger` is the default for binary versions `7.0.0` and higher.
+Older versions (before `7.0.0`) will still continue to use `ephemeralForTest` by default.
+
+It is recommended to run those instances with a db path which is equivalent to [`tmpfs`](https://wiki.archlinux.org/title/tmpfs).

packages/mongodb-memory-server-core/src/MongoMemoryReplSet.ts

@@ -81,7 +81,7 @@ export interface ReplSetOpts {
   spawn?: SpawnOptions;
   /**
    *`mongod` storage engine type
-   * @default 'ephemeralForTest'
+   * @default 'ephemeralForTest' unless mongodb version is `7.0.0`, where its `wiredTiger`
    */
   storageEngine?: StorageEngine;
   /**

packages/mongodb-memory-server-core/src/MongoMemoryServer.ts

@@ -20,6 +20,8 @@ import { promises as fspromises } from 'fs';
 import { AddUserOptions, MongoClient } from 'mongodb';
 import { InstanceInfoError, StateError } from './util/errors';
 import * as os from 'os';
+import { DryMongoBinary } from './util/DryMongoBinary';
+import * as semver from 'semver';
 
 const log = debug('MongoMS:MongoMemoryServer');
 
@@ -375,12 +377,33 @@ export class MongoMemoryServer extends EventEmitter implements ManagerAdvanced {
       port = await this.getNewPort(port);
     }
 
+    const opts = await DryMongoBinary.generateOptions(this.opts.binary);
+    let storageEngine = instOpts.storageEngine;
+
+    // warn when storage engine "ephemeralForTest" is explicitly used and switch to "wiredTiger"
+    if (storageEngine === 'ephemeralForTest' && semver.gte(opts.version, '7.0.0')) {
+      console.warn(
+        'Storage Engine "ephemeralForTest" is removed since mongodb 7.0.0, automatically using "wiredTiger"!\n' +
+          'This warning is because the mentioned storage engine is explicitly used and mongodb version is 7.0.0 or higher'
+      );
+
+      storageEngine = 'wiredTiger';
+    }
+
+    if (isNullOrUndefined(storageEngine)) {
+      if (semver.gte(opts.version, '7.0.0')) {
+        storageEngine = 'wiredTiger';
+      } else {
+        storageEngine = 'ephemeralForTest';
+      }
+    }
+
     // consider directly using "this.opts.instance", to pass through all options, even if not defined in "StartupInstanceData"
     const data: StartupInstanceData = {
       port: port,
       dbName: generateDbName(instOpts.dbName),
       ip: instOpts.ip ?? '127.0.0.1',
-      storageEngine: instOpts.storageEngine ?? 'ephemeralForTest',
+      storageEngine: storageEngine,
       replSet: instOpts.replSet,
       dbPath: instOpts.dbPath,
       tmpDir: undefined,

packages/mongodb-memory-server-core/src/__tests__/MongoMemoryServer.test.ts

@@ -1113,4 +1113,28 @@ describe('MongoMemoryServer', () => {
       mongoServer._instanceInfo.tmpDir!
     ); // manual cleanup
   });
+
+  describe('server version specific', () => {
+    // should use default options that are supported for 7.0 (like not using "ephemeralForTest" by default)
+    it('should allow mongodb by default 7.0', async () => {
+      const server = await MongoMemoryServer.create({ binary: { version: '7.0.0' } });
+
+      await server.stop();
+    });
+
+    it('should warn if "ephemeralForTest" is used explicitly in mongodb 7.0', async () => {
+      const spy = jest.spyOn(console, 'warn').mockImplementationOnce(() => {});
+      const server = await MongoMemoryServer.create({
+        binary: { version: '7.0.0' },
+        instance: { storageEngine: 'ephemeralForTest' },
+      });
+
+      expect(console.warn).toHaveBeenCalledTimes(1);
+      expect(spy.mock.calls).toMatchSnapshot();
+
+      expect(server.instanceInfo?.storageEngine).toStrictEqual('wiredTiger');
+
+      await server.stop();
+    });
+  });
 });

packages/mongodb-memory-server-core/src/__tests__/__snapshots__/MongoMemoryServer.test.ts.snap

@@ -36,6 +36,15 @@ This may be because of using a v6.x way of calling functions, look at the follow
 https://nodkz.github.io/mongodb-memory-server/docs/guides/migration/migrate7#no-function-other-than-start-create-ensureinstance-will-be-starting-anything"
 `;
 
+exports[`MongoMemoryServer server version specific should warn if "ephemeralForTest" is used explicitly in mongodb 7.0 1`] = `
+Array [
+  Array [
+    "Storage Engine \\"ephemeralForTest\\" is removed since mongodb 7.0.0, automatically using \\"wiredTiger\\"!
+This warning is because the mentioned storage engine is explicitly used and mongodb version is 7.0.0 or higher",
+  ],
+]
+`;
+
 exports[`MongoMemoryServer start() should throw an error if state is not "new" or "stopped" 1`] = `
 "Incorrect State for operation: \\"starting\\", allowed States: \\"[new,stopped]\\"
 This may be because of using a v6.x way of calling functions, look at the following guide if anything applies: