docs(idempotency): review API docs & README

.markdownlintignore

@@ -13,7 +13,6 @@ LICENSE
 # these will be removed from the ignore and linted in future PRs
 packages/batch/README.md
 packages/commons/README.md
-packages/idempotency/README.md
 packages/jmespath/README.md
 packages/logger/README.md
 packages/metrics/README.md

examples/snippets/idempotency/samples/testingIdempotency.json

@@ -0,0 +1,30 @@
+{
+  "version": "2.0",
+  "routeKey": "ANY /createpayment",
+  "rawPath": "/createpayment",
+  "rawQueryString": "",
+  "headers": {
+    "Header1": "value1",
+    "X-Idempotency-Key": "abcdefg"
+  },
+  "requestContext": {
+    "accountId": "123456789012",
+    "apiId": "api-id",
+    "domainName": "id.execute-api.us-east-1.amazonaws.com",
+    "domainPrefix": "id",
+    "http": {
+      "method": "POST",
+      "path": "/createpayment",
+      "protocol": "HTTP/1.1",
+      "sourceIp": "ip",
+      "userAgent": "agent"
+    },
+    "requestId": "id",
+    "routeKey": "ANY /createpayment",
+    "stage": "$default",
+    "time": "10/Feb/2021:13:40:43 +0000",
+    "timeEpoch": 1612964443723
+  },
+  "body": "{\"user\":\"xyz\",\"productId\":\"123456789\"}",
+  "isBase64Encoded": false
+}

examples/snippets/idempotency/testingIdempotency.test.ts

@@ -0,0 +1,38 @@
+import type { Context } from 'aws-lambda';
+import { DocumentClient } from 'aws-sdk/clients/dynamodb';
+import * as API_GATEWAY_EXAMPLE_EVENT from './samples/testingIdempotency.json';
+import { idempotentHandler } from './testingIdempotency';
+
+describe('Idempotent Handler', () => {
+  const ddb = new DocumentClient({});
+
+  it('should return the same response for the same request', async () => {
+    // given
+    const context = {} as Context;
+
+    const firstRequest = API_GATEWAY_EXAMPLE_EVENT;
+
+    // modify time field to simulate a different request
+    const secondRequest = {
+      ...API_GATEWAY_EXAMPLE_EVENT,
+      requestContext: {
+        ...API_GATEWAY_EXAMPLE_EVENT.requestContext,
+        time: 1612964493723,
+      },
+    };
+
+    // when
+    const firstResponse = await idempotentHandler(firstRequest, context);
+    const secondResponse = await idempotentHandler(secondRequest, context);
+    // then
+    expect(firstResponse).toEqual(secondResponse);
+    // check if we only have one item in the table
+    const idempotencyRecords = await ddb
+      .scan({ TableName: 'idempotency-store' })
+      .promise();
+
+    expect(idempotencyRecords.Items).toHaveLength(1);
+    expect(idempotencyRecords.Items?.[0].status).toEqual('COMPLETED');
+    expect(idempotencyRecords.Items?.[0].data).toEqual(firstResponse);
+  });
+});

examples/snippets/idempotency/testingIdempotency.ts

@@ -0,0 +1,24 @@
+import {
+  IdempotencyConfig,
+  makeIdempotent,
+} from '@aws-lambda-powertools/idempotency';
+import { DynamoDBPersistenceLayer } from '@aws-lambda-powertools/idempotency/dynamodb';
+
+const idempotencyConfig = new IdempotencyConfig({});
+const persistenceStore = new DynamoDBPersistenceLayer({
+  tableName: 'idempotency-store',
+});
+
+const handler = async (event: unknown, context: unknown) => {
+  return {
+    statusCode: 200,
+    body: JSON.stringify({ message: 'Success', event: event }),
+  };
+};
+
+const idempotentHandler = makeIdempotent(handler, {
+  config: idempotencyConfig,
+  persistenceStore: persistenceStore,
+});
+
+export { idempotentHandler };