docs(integration-examples): add example on how to use with "jest"

closes #319

docs/guides/integration-examples.md

@@ -0,0 +1,80 @@
+---
+id: integration-examples
+title: 'Integration Examples'
+---
+
+This Guide will show how `mongodb-memory-server` can be used with different frameworks
+
+## jest
+
+For useage with `jest` it is recommended to use the [`globalSetup`](https://jestjs.io/docs/en/configuration#globalsetup-string) and [`globalTeardown`](https://jestjs.io/docs/en/configuration#globalteardown-string) options
+
+`jest.config.json`:
+
+```ts
+{
+  "preset": "ts-jest",
+  "globalSetup": "<rootDir>/test/globalSetup.ts",
+  "globalTeardown": "<rootDir>/test/globalTeardown.ts",
+  "setupFilesAfterEnv": [
+    "<rootDir>/test/setupFile.ts"
+  ]
+}
+
+```
+
+`globalSetup.ts`:
+
+```ts
+import { MongoMemoryServer } from 'mongodb-memory-server';
+import * as mongoose from 'mongoose';
+import { config } from './utils/config';
+
+export = async function globalSetup() {
+  if (config.Memory) { // Config to decided if an mongodb-memory-server instance should be used
+    // it's needed in global space, because we don't want to create a new instance every test-suite
+    const instance = await MongoMemoryServer.create();
+    const uri = instance.getUri();
+    (global as any).__MONGOINSTANCE = instance;
+    process.env.MONGO_URI = uri.slice(0, uri.lastIndexOf('/'));
+  } else {
+    process.env.MONGO_URI = `mongodb://${config.IP}:${config.Port}`;
+  }
+
+  // The following is to make sure the database is clean before an test starts
+  await mongoose.connect(`${process.env.MONGO_URI}/${config.DataBase}`, { useNewUrlParser: true, useUnifiedTopology: true });
+  await mongoose.connection.db.dropDatabase();
+  await mongoose.disconnect();
+};
+
+```
+
+`globalTeardown.ts`:
+
+```ts
+import { MongoMemoryServer } from 'mongodb-memory-server';
+import { config } from './utils/config';
+
+export = async function globalTeardown() {
+  if (config.Memory) { // Config to decided if an mongodb-memory-server instance should be used
+    const instance: MongoMemoryServer = (global as any).__MONGOINSTANCE;
+    await instance.stop();
+  }
+};
+```
+
+and an [`setupFilesAfterEnv`](https://jestjs.io/docs/en/configuration#setupfilesafterenv-array) can be used to connect something like `mongoose` or `mongodb`
+
+`setupFile.ts`:
+
+```ts
+import { connect, disconnect } from './utils/connect';
+
+beforeAll(async () => {
+  await connect();
+});
+
+afterAll(async () => {
+  await disconnect();
+});
+```

website/sidebars.js

@@ -4,6 +4,6 @@ module.exports = {
     "Classes": ["api/mongo-memory-server", "api/mongo-memory-replset", "api/mongo-instance", "api/mongo-binary"]
   },
   guides: {
-    "Getting Started": ["guides/quick-start-guide", "guides/error-warning-details", "guides/faq", "guides/supported-systems"]
+    "Getting Started": ["guides/quick-start-guide", "guides/error-warning-details", "guides/faq", "guides/supported-systems", "guides/integration-examples"]
   }
 };