Merge pull request #1 from alphagov/add-pay-specific-event-format

Add pay specific event format

src/process.ts

@@ -1,9 +1,10 @@
 import S3Provider from './providers/S3Provider'
 import SQSConsumer from './consumers/SQSConsumer'
+import GovUkPayPaymentEventMessage from './transformers/GovUKPayPaymentEventMessage'
 const { PROVIDER_S3_BUCKET_NAME, PROVIDER_S3_SOURCE_FILE, CONSUMER_SQS_QUEUE_URL } = process.env
 
 const s3Provider = new S3Provider(PROVIDER_S3_BUCKET_NAME, PROVIDER_S3_SOURCE_FILE)
-const sqs = new SQSConsumer(CONSUMER_SQS_QUEUE_URL).writer()
+const sqs = new SQSConsumer(CONSUMER_SQS_QUEUE_URL, new GovUkPayPaymentEventMessage()).writer()
 
 s3Provider
 	.stream()

src/transformers/GovUKPayPaymentEventMessage.test.ts

@@ -0,0 +1,41 @@
+import GovUKPayPaymentEventMessage from './GovUKPayPaymentEventMessage'
+describe('message formatter', () => {
+	const messageFromS3Csv = {
+		'transaction_id': 'some-transaction-id',
+		'event_date': 'some-event-date',
+		'parent_transaction_id': 'some-parent-transaction-id',
+		'event_name': 'some-event-type',
+		'transaction_type': 'some-resource-type',
+		'reference': 'some-reference',
+		'amount': 'some-amount'
+	}
+	const messageBuilder = new GovUKPayPaymentEventMessage()
+
+	test('correctly transforms known reserved columns', () => {
+		const formatted = messageBuilder.transform(messageFromS3Csv)
+		const body = JSON.parse(formatted.MessageBody)
+
+		expect(body).toHaveProperty('resource_external_id')
+		expect(body).toHaveProperty('parent_resource_external_id')
+		expect(body).toHaveProperty('resource_type')
+		expect(body).toHaveProperty('timestamp')
+		expect(body).toHaveProperty('event_details')
+		expect(body).toHaveProperty('event_type')
+	})
+
+	test('ignores reserved properties if not needed on transaction', () => {
+		const formatted = messageBuilder.transform({ 'transaction_id': 'some-transaction-id' })
+		const body = JSON.parse(formatted.MessageBody)
+
+		expect(body).toHaveProperty('resource_external_id')
+		expect(body).not.toHaveProperty('parent_resource_external_id')
+	})
+
+	test('correctly formats well formatted flat message', () => {
+		const formatted = messageBuilder.transform(messageFromS3Csv)
+		const body = JSON.parse(formatted.MessageBody)
+
+		expect(body.event_details.reference).toBe('some-reference')
+		expect(body.event_details.amount).toBe('some-amount')
+	})
+})

src/transformers/GovUKPayPaymentEventMessage.ts

@@ -0,0 +1,55 @@
+/* eslint-disable @typescript-eslint/camelcase */
+import crypto from 'crypto'
+import SQS = require("aws-sdk/clients/sqs")
+import Transformer from './Transformer'
+import { Message } from './../providers/Provider'
+
+interface PaymentEventMessage {
+	event_details: { [key: string]: string };
+	resource_type?: string;
+	resource_external_id?: string;
+	event_date?: string;
+	event_type?: string;
+	parent_resource_external_id?: string;
+	[key: string]: string | { [key: string]: string };
+}
+
+// we can gaurantee the existence of required fields as anything with permissions
+// to this resource will be validating data entry
+function formatPaymentEventMessage(message: Message): PaymentEventMessage {
+	const reservedKeys = [
+		{ key: 'transaction_id', target: 'resource_external_id' },
+		{ key: 'parent_transaction_id', target: 'parent_resource_external_id' },
+		{ key: 'transaction_type', target: 'resource_type' },
+		{ key: 'event_date', target: 'timestamp' },
+		{ key: 'event_name', target: 'event_type' }
+	]
+	const formatted: PaymentEventMessage = { event_details: {} }
+
+	// initially extract the reserved properties
+	for (const reserved of reservedKeys) {
+		const reservedEntry = message[reserved.key]
+		if (reservedEntry) {
+			formatted[reserved.target] = reservedEntry
+			delete message[reserved.key]
+		}
+	}
+
+	// any remaining properties will override attributes of the transaction itself
+	// put these in `event_data`
+	for (const paymentEventMessageKey in message) {
+		formatted.event_details[paymentEventMessageKey] = message[paymentEventMessageKey]
+	}
+	return formatted
+}
+
+export default class GovUkPayPaymentEventMessage implements Transformer {
+	transform(message: Message): SQS.SendMessageBatchRequestEntry {
+		return {
+			Id: crypto.randomBytes(16).toString('hex'),
+			MessageBody: JSON.stringify(
+				formatPaymentEventMessage(message)
+			)
+		}
+	}
+}