feat: use csv-stringify library

.projenrc.js

@@ -11,7 +11,7 @@ const project = new awscdk.AwsCdkTypeScriptApp({
     "@aws-sdk/client-dynamodb",
     "@aws-sdk/client-s3",
     "@aws-sdk/lib-storage",
-    "stream-transform",
+    "csv-stringify",
     "@aws-prototyping-sdk/pdk-nag",
     "cdk-nag",
     "cdk-pipelines-github",

src/services/export.lambda.ts

@@ -1,44 +1,36 @@
-import { PassThrough } from "stream";
-import {
-  AttributeValue,
-  DynamoDBClient,
-  paginateScan,
-} from "@aws-sdk/client-dynamodb";
+import { DynamoDBClient, paginateScan } from "@aws-sdk/client-dynamodb";
 import { S3Client } from "@aws-sdk/client-s3";
 import { Upload } from "@aws-sdk/lib-storage";
-import { transform } from "stream-transform";
+import { stringify } from "csv-stringify";
 
-const ddbClient = new DynamoDBClient({});
 const s3Client = new S3Client({});
+const ddbItemsPaginator = paginateScan(
+  {
+    client: new DynamoDBClient({}),
+  },
+  {
+    TableName: process.env.DATA_TABLE_NAME,
+  }
+);
 
 export const handler = async () => {
-  const ddbItemsPaginator = paginateScan(
-    {
-      client: ddbClient,
-    },
-    {
-      TableName: process.env.DATA_TABLE_NAME,
-    }
-  );
-
-  const csvTransform = transform((record: Record<string, AttributeValue>) => {
-    return Object.keys(record)
-      .map((field) => JSON.stringify(record[field]))
-      .join(",");
-  });
-
+  const stringifier = stringify();
   const upload = new Upload({
     client: s3Client,
     params: {
       Bucket: process.env.DESTINATION_BUCKET_NAME,
       Key: new Date().toISOString().split("T")[0] + ".csv",
-      Body: csvTransform.pipe(new PassThrough()),
+      Body: stringifier,
     },
     leavePartsOnError: false,
   });
 
   for await (const page of ddbItemsPaginator) {
-    page.Items?.forEach((item) => csvTransform.write(item));
+    page.Items?.forEach((item) =>
+      stringifier.write(
+        Object.keys(item).map((field) => JSON.stringify(item[field]))
+      )
+    );
   }
 
   return upload.done();