JSON parsing of event parameter in AWS Lambda extracts undefined - json

Question

This was working, and suddenly fails on extracting the "event.body" JSON object passed into this AWS Lambda nodeJS function:
exports.handler = function (event, context, callback) {
console.log('Event: ' + JSON.stringify(event));
console.log('Event.Body: ' + event.body);
//console.log('Parsed Event: ' + JSON.parse(event));
let body = event.body;
console.log('Body: ' + body);
const tgQueryName = body.queryName;
const tgQueryParams = body.queryParams;
console.log('tgQueryName: ' + tgQueryName);
console.log('tgQueryParams: ' + tgQueryParams);
...
Both tgQueryName and tgQueryParams are 'undefined' - see CloudWatch log:
INFO Event: {"version":"2.0","routeKey":"POST /tg-query","rawPath":"/dev/tg-query","rawQueryString":"","headers":{"accept":"application/json, text/plain, */*","accept-encoding":"gzip, deflate","accept-language":"he-IL,he;q=0.9,en-US;q=0.8,en;q=0.7","cache-control":"no-cache","content-length":"51","content-type":"application/json; charset=UTF-8","host":"p6ilp2ts0g.execute-api.us-east-1.amazonaws.com","origin":"http://localhost","referer":"http://localhost/","sec-fetch-dest":"empty","sec-fetch-mode":"cors","sec-fetch-site":"cross-site","user-agent":"Mozilla/5.0 (Linux; Android 11; Redmi Note 8 Build/RKQ1.201004.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/101.0.4951.61 Mobile Safari/537.36","x-amzn-trace-id":"Root=1-629b960c-072e8fa475ad26f56893c6f9","x-forwarded-for":"89.139.32.60","x-forwarded-port":"443","x-forwarded-proto":"https","x-requested-with":"com.skillblaster.simplify.dev"},"requestContext":{"accountId":"140360121027","apiId":"p6ilp2ts0g","domainName":"p6ilp2ts0g.execute-api.us-east-1.amazonaws.com","domainPrefix":"p6ilp2ts0g","http":{"method":"POST","path":"/dev/tg-query","protocol":"HTTP/1.1","sourceIp":"89.139.32.60","userAgent":"Mozilla/5.0 (Linux; Android 11; Redmi Note 8 Build/RKQ1.201004.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/101.0.4951.61 Mobile Safari/537.36"},"requestId":"TNRh_gq-oAMESEw=","routeKey":"POST /tg-query","stage":"dev","time":"04/Jun/2022:17:27:40 +0000","timeEpoch":1654363660597},"body":"{\"queryName\":\"getActiveCountries\",\"queryParams\":{}}","isBase64Encoded":false}
INFO Event.Body: {"queryName":"getActiveCountries","queryParams":{}}
INFO Body: {"queryName":"getActiveCountries","queryParams":{}}
INFO tgQueryName: undefined
INFO tgQueryParams: undefined
I also tried: body["queryName"] - same result.
What am I missing?

Answer 1

Your body content is a string and you need to JSON.parse it:
let body = JSON.parse(event.body);
It was only clear when I stuck your initial event JSON into a JSON beautifier and it was a little clearer.