Node errorhandling (#170)

* added code

* removed cdk code

* added code examples

* added ts files

* added code

* updated code

* error handling code

* Update nodejs/errorhandling/js/index.js

Co-authored-by: Pratik Das <pratikd2001@gmail.com>
Co-authored-by: Tom Hombergs <tom.hombergs@gmail.com>

nodejs/errorhandling/js/lambda.js

@@ -0,0 +1,33 @@
+console.log('Loading function');
+
+const validateRecord = (recordElement)=>{
+    // record is considered valid if contains status field
+    return recordElement.includes("status")
+}
+
+exports.handler = async (event, context) => {
+    /* Process the list of records and transform them */
+    const output = event.records.map((record)=>{
+        const decodedData = Buffer.from(record.data, "base64").toString("utf-8")
+        let isValidRecord = validateRecord(decodedData)
+
+        if(isValidRecord){
+            let parsedRecord = JSON.parse(decodedData)
+            // read fields from parsed JSON for some more processing
+            const outputRecord = `status::${parsedRecord.status}`
+            return {
+                recordId: record.recordId,
+                result: 'Ok',
+                // payload is encoded back to base64 before returning the result
+                data:  Buffer.from(outputRecord, "utf-8").toString("base64")
+            }
+
+        }else{
+            return {
+                recordId: record.recordId,
+                result: 'dropped',
+                data: record.data // payload is kept intact,
+            }
+        }
+    })
+};