tests: add unit test suite for MongoMemoryServer

Author: AJRdev

src/__tests__/MongoMemoryServer-test.ts

@@ -0,0 +1,87 @@
+import MongoMemoryServer from '../MongoMemoryServer';
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 600000;
+
+describe('MongoMemoryServer', () => {
+  describe('start', () => {
+    const mockStartUpInstance = jest.fn();
+
+    afterEach(() => {
+      mockStartUpInstance.mockClear();
+    });
+
+    it('should resolve to true if an MongoInstanceData is resolved by _startUpInstance', async () => {
+      mockStartUpInstance.mockResolvedValue({});
+      MongoMemoryServer.prototype._startUpInstance = mockStartUpInstance;
+
+      const mongoServer = new MongoMemoryServer({ autoStart: false });
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(0);
+
+      await expect(mongoServer.start()).resolves.toEqual(true);
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(1);
+    });
+
+    it('_startUpInstance should be called a second time if an error is thrown on the first call and assign the current port to nulll', async () => {
+      mockStartUpInstance
+        .mockRejectedValueOnce(new Error('Mongod shutting down'))
+        .mockResolvedValueOnce({});
+      MongoMemoryServer.prototype._startUpInstance = mockStartUpInstance;
+
+      const mongoServer = new MongoMemoryServer({
+        autoStart: false,
+        instance: {
+          port: 123,
+        },
+      });
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(0);
+
+      await expect(mongoServer.start()).resolves.toEqual(true);
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(2);
+    });
+
+    it('should throw an error if _startUpInstance throws an unknown error', async () => {
+      mockStartUpInstance.mockRejectedValueOnce(new Error('unknown error'));
+      MongoMemoryServer.prototype._startUpInstance = mockStartUpInstance;
+
+      const mongoServer = new MongoMemoryServer({
+        autoStart: false,
+        instance: {
+          port: 123,
+        },
+      });
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(0);
+
+      await expect(mongoServer.start()).rejects.toThrow(
+        `unknown error\n\nUse debug option for more info: ` +
+          `new MongoMemoryServer({ debug: true })`
+      );
+
+      expect(mockStartUpInstance).toHaveBeenCalledTimes(1);
+    });
+  });
+  describe('getInstanceData', () => {
+    const mockStart = jest.fn();
+
+    afterEach(() => {
+      mockStart.mockClear();
+    });
+
+    it('should throw an error if not instance is running after calling start', async () => {
+      mockStart.mockResolvedValue(true);
+      MongoMemoryServer.prototype.start = mockStart;
+
+      const mongoServer = new MongoMemoryServer({ autoStart: false });
+
+      await expect(mongoServer.getInstanceData()).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.'
+      );
+
+      expect(mockStart).toHaveBeenCalledTimes(1);
+    });
+  });
+});

src/__tests__/singleDB-test.ts

@@ -1,8 +1,7 @@
 import { Db, MongoClient } from 'mongodb';
-import MongoMemoryServer from '../MongoMemoryServer';
+import MongoMemoryServer, { MongoInstanceDataT } from '../MongoMemoryServer';
 
 jasmine.DEFAULT_TIMEOUT_INTERVAL = 600000;
-
 let con: MongoClient;
 let db: Db;
 let mongoServer: MongoMemoryServer;
@@ -27,4 +26,19 @@ describe('Single mongoServer', () => {
     expect(result.result).toMatchSnapshot();
     expect(await col.countDocuments({})).toBe(2);
   });
+
+  it('should get URI of specified DB name', async () => {
+    const port: number = await mongoServer.getPort();
+    expect(await mongoServer.getUri('dumb')).toBe(`mongodb://127.0.0.1:${port}/dumb`);
+  });
+
+  it('should throw error on start if there is already a running instance', async () => {
+    const mongoServer2 = new MongoMemoryServer({ autoStart: false });
+
+    mongoServer2.runningInstance = Promise.resolve({}) as Promise<MongoInstanceDataT>;
+
+    await expect(mongoServer2.start()).rejects.toThrow(
+      'MongoDB instance already in status startup/running/error. Use opts.debug = true for more info.'
+    );
+  });
 });

src/util/__tests__/MongoBinaryDownload-test.ts

@@ -86,7 +86,6 @@ the same as in the reference result`, () => {
     );
   });
 
-  // TODO : weird test fail error TypeError: jasmine.Spec.isPendingSpecException is not a function
   it('false value of checkMD5 attribute disables makeMD5check validation', async () => {
     expect.assertions(1);
     (fs.readFileSync as jest.Mock).mockImplementationOnce(() => 'someMd5 fileName');