feat: add addCORSHeaders()

Author: coderbyheart

src/addCORSHeaders.ts

@@ -0,0 +1,25 @@
+import type { MiddlewareObj, Request } from '@middy/core'
+import type {
+	APIGatewayProxyEventV2,
+	APIGatewayProxyStructuredResultV2,
+} from 'aws-lambda'
+
+export const addCORSHeaders = (
+	AccessControlAllowOrigin: string = '*',
+): MiddlewareObj<APIGatewayProxyEventV2, APIGatewayProxyStructuredResultV2> => {
+	const setCORSHeaders = async (req: Request) => {
+		if (req.response === null) return
+		req.response = {
+			...req.response,
+			headers: {
+				...(req.response.headers ?? {}),
+				'Access-Control-Allow-Origin': AccessControlAllowOrigin,
+			},
+		}
+	}
+
+	return {
+		after: setCORSHeaders,
+		onError: setCORSHeaders,
+	}
+}