fix(MongoMemoryServer): rename getInstanceData() to ensureInstance(). Replace isRunning() on getInstanceInfo() sync method.

Closes #152

Author: nodkz

README.md

@@ -40,13 +40,13 @@ const dbName = await mongod.getDbName();
 //   ... where you may use `uri` for as a connection string for mongodb or mongoose
 
 // you may check instance status, after you got `uri` it must be `true`
-mongod.isRunning(); // return true
+mongod.getInstanceInfo(); // return Object with instance data
 
 // you may stop mongod manually
 await mongod.stop();
 
 // when mongod killed, it's running status should be `false`
-mongod.isRunning();
+mongod.getInstanceInfo();
 
 // even you forget to stop `mongod` when you exit from script
 // special childProcess killer will shutdown it for you

src/MongoMemoryServer.ts

@@ -12,6 +12,7 @@ import {
   SpawnOptions,
 } from './types';
 import { SynchrounousResult } from 'tmp';
+import { deprecate } from './util/deprecate';
 
 tmp.setGracefulCleanup();
 
@@ -43,13 +44,13 @@ const generateConnectionString = async (port: number, dbName: string): Promise<s
 };
 
 export default class MongoMemoryServer {
-  runningInstance: Promise<MongoInstanceDataT> | null;
+  runningInstance: Promise<MongoInstanceDataT> | null = null;
+  instanceInfoSync: MongoInstanceDataT | null = null;
   opts: MongoMemoryServerOptsT;
   debug: DebugFn;
 
   constructor(opts?: MongoMemoryServerOptsT) {
     this.opts = { ...opts };
-    this.runningInstance = null;
 
     this.debug = (msg: string) => {
       if (this.opts.debug) {
@@ -62,10 +63,6 @@ export default class MongoMemoryServer {
     }
   }
 
-  isRunning(): boolean {
-    return !!this.runningInstance;
-  }
-
   async start(): Promise<boolean> {
     this.debug('Called MongoMemoryServer.start() method:');
     if (this.runningInstance) {
@@ -95,7 +92,10 @@ export default class MongoMemoryServer {
         throw err;
       });
 
-    return this.runningInstance.then(() => true);
+    return this.runningInstance.then((data) => {
+      this.instanceInfoSync = data;
+      return true;
+    });
   }
 
   async _startUpInstance(): Promise<MongoInstanceDataT> {
@@ -149,22 +149,36 @@ export default class MongoMemoryServer {
   async stop(): Promise<boolean> {
     this.debug('Called MongoMemoryServer.stop() method');
 
-    const { instance, port, tmpDir }: MongoInstanceDataT = await this.getInstanceData();
+    const { instance, port, tmpDir }: MongoInstanceDataT = await this.ensureInstance();
 
     this.debug(`Shutdown MongoDB server on port ${port} with pid ${instance.getPid() || ''}`);
     await instance.kill();
 
+    this.runningInstance = null;
+    this.instanceInfoSync = null;
+
     if (tmpDir) {
       this.debug(`Removing tmpDir ${tmpDir.name}`);
       tmpDir.removeCallback();
     }
 
-    this.runningInstance = null;
     return true;
   }
 
+  getInstanceInfo(): MongoInstanceDataT | false {
+    return this.instanceInfoSync || false;
+  }
+
+  /* @deprecated 5.0.0 */
   async getInstanceData(): Promise<MongoInstanceDataT> {
-    this.debug('Called MongoMemoryServer.getInstanceData() method:');
+    deprecate(
+      `method MongoMemoryServer.getInstanceData() will be deprecated. Please use 'MongoMemoryServer.ensureInstance()' method instead.`
+    );
+    return this.ensureInstance();
+  }
+
+  async ensureInstance(): Promise<MongoInstanceDataT> {
+    this.debug('Called MongoMemoryServer.ensureInstance() method:');
     if (!this.runningInstance) {
       this.debug(' - no running instance, call `start()` command');
       await this.start();
@@ -179,7 +193,7 @@ export default class MongoMemoryServer {
   }
 
   async getUri(otherDbName: string | boolean = false): Promise<string> {
-    const { uri, port }: MongoInstanceDataT = await this.getInstanceData();
+    const { uri, port }: MongoInstanceDataT = await this.ensureInstance();
 
     // IF true OR string
     if (otherDbName) {
@@ -199,17 +213,17 @@ export default class MongoMemoryServer {
   }
 
   async getPort(): Promise<number> {
-    const { port }: MongoInstanceDataT = await this.getInstanceData();
+    const { port }: MongoInstanceDataT = await this.ensureInstance();
     return port;
   }
 
   async getDbPath(): Promise<string> {
-    const { dbPath }: MongoInstanceDataT = await this.getInstanceData();
+    const { dbPath }: MongoInstanceDataT = await this.ensureInstance();
     return dbPath;
   }
 
   async getDbName(): Promise<string> {
-    const { dbName }: MongoInstanceDataT = await this.getInstanceData();
+    const { dbName }: MongoInstanceDataT = await this.ensureInstance();
     return dbName;
   }
 }

src/__tests__/MongoMemoryServer-test.ts

@@ -65,13 +65,13 @@ describe('MongoMemoryServer', () => {
     });
   });
 
-  describe('getInstanceData()', () => {
+  describe('ensureInstance()', () => {
     it('should throw an error if not instance is running after calling start', async () => {
       MongoMemoryServer.prototype.start = jest.fn(() => Promise.resolve(true));
 
       const mongoServer = new MongoMemoryServer({ autoStart: false });
 
-      await expect(mongoServer.getInstanceData()).rejects.toThrow(
+      await expect(mongoServer.ensureInstance()).rejects.toThrow(
         'Database instance is not running. You should start database by calling start() method. BTW it should start automatically if opts.autoStart!=false. Also you may provide opts.debug=true for more info.'
       );
 
@@ -82,15 +82,22 @@ describe('MongoMemoryServer', () => {
   describe('stop()', () => {
     it('should stop mongod and answer on isRunning() method', async () => {
       const mongod = new MongoMemoryServer({
-        autoStart: true,
+        autoStart: false,
         debug: false,
       });
 
-      await mongod.getInstanceData();
+      expect(mongod.getInstanceInfo()).toBeFalsy();
+      mongod.start();
+      // while mongod launching `getInstanceInfo` is false
+      expect(mongod.getInstanceInfo()).toBeFalsy();
+
+      // when instance launched then data became avaliable
+      await mongod.ensureInstance();
+      expect(mongod.getInstanceInfo()).toBeDefined();
 
-      expect(mongod.isRunning()).toBeTruthy();
+      // after stop, instance data should be empty
       await mongod.stop();
-      expect(mongod.isRunning()).toBeFalsy();
+      expect(mongod.getInstanceInfo()).toBeFalsy();
     });
   });
 });

src/util/deprecate.ts

@@ -0,0 +1,13 @@
+export function deprecate(msg: string): void {
+  let stack;
+  let stackStr = '';
+  const error = new Error();
+
+  if (error.stack) {
+    stack = error.stack.replace(/^\s+at\s+/gm, '').split('\n');
+    stackStr = `\n    ${stack.slice(2, 7).join('\n    ')}`;
+  }
+
+  // eslint-disable-next-line
+  console.log(`[mongodb-memory-server]: DEPRECATION MESSAGE: ${msg} ${stackStr}\n\n`);
+}