Add DynamoDB usage example (#8319)

* docs: add dynamodb page to website sidebar

* docs: add DynamoDB usage tutorial

* docs: mention new dynamodb guide in CHANGELOG.md

* style: apply prettier style suggestions

CHANGELOG.md

@@ -6,6 +6,7 @@
 - `[jest-cli]` Update `--forceExit` and "did not exit for one second" message colors ([#8329](https://github.com/facebook/jest/pull/8329))
 - `[expect]` Improve report when matcher fails, part 16 ([#8306](https://github.com/facebook/jest/pull/8306))
 - `[jest-runner]` Pass docblock pragmas to TestEnvironment constructor ([#8320](https://github.com/facebook/jest/pull/8320))
+- `[docs]` Add DynamoDB guide ([#8319](https://github.com/facebook/jest/pull/8319))
 
 ### Fixes
 

docs/DynamoDB.md

@@ -0,0 +1,81 @@
+---
+id: dynamodb
+title: Using with DynamoDB
+---
+
+With the [Global Setup/Teardown](Configuration.md#globalsetup-string) and [Async Test Environment](Configuration.md#testenvironment-string) APIs, Jest can work smoothly with [DynamoDB](https://aws.amazon.com/dynamodb/).
+
+## Use jest-dynamodb Preset
+
+[Jest DynamoDB](https://github.com/shelfio/jest-dynamodb) provides all required configuration to run your tests using DynamoDB.
+
+1.  First install `@shelf/jest-dynamodb`
+
+```
+yarn add @shelf/jest-dynamodb --dev
+```
+
+2.  Specify preset in your Jest configuration:
+
+```json
+{
+  "preset": "@shelf/jest-dynamodb"
+}
+```
+
+3.  Create `jest-dynamodb-config.js` and define DynamoDB tables
+
+See [Create Table API](https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html#createTable-property)
+
+```js
+module.exports = {
+  tables: [
+    {
+      TableName: `files`,
+      KeySchema: [{AttributeName: 'id', KeyType: 'HASH'}],
+      AttributeDefinitions: [{AttributeName: 'id', AttributeType: 'S'}],
+      ProvisionedThroughput: {ReadCapacityUnits: 1, WriteCapacityUnits: 1},
+    },
+    // etc
+  ],
+};
+```
+
+4.  Configure DynamoDB client
+
+```js
+const {DocumentClient} = require('aws-sdk/clients/dynamodb');
+
+const isTest = process.env.JEST_WORKER_ID;
+const config = {
+  convertEmptyValues: true,
+  ...(isTest && {
+    endpoint: 'localhost:8000',
+    sslEnabled: false,
+    region: 'local-env',
+  }),
+};
+
+const ddb = new DocumentClient(config);
+```
+
+5.  Write tests
+
+```js
+it('should insert item into table', async () => {
+  await ddb
+    .put({TableName: 'files', Item: {id: '1', hello: 'world'}})
+    .promise();
+
+  const {Item} = await ddb.get({TableName: 'files', Key: {id: '1'}}).promise();
+
+  expect(Item).toEqual({
+    id: '1',
+    hello: 'world',
+  });
+});
+```
+
+There's no need to load any dependencies.
+
+See [documentation](https://github.com/shelfio/jest-dynamodb) for details.

website/sidebars.json

@@ -20,6 +20,7 @@
       "webpack",
       "puppeteer",
       "mongodb",
+      "dynamodb",
       "tutorial-jquery",
       "watch-plugins",
       "migration-guide",