Integrating lambda with IBM tone_chat error

Question

I'm trying to integrate my lambda function with IBM Tone_chat sentiment analyzer. I'm getting an error of:

"errorMessage": "The first argument must be one of type string or Buffer. Received type undefined"

here is my event:

{ "utterances": [
        {"text": "Hello, can you help me", "user": "customer"},
        {"text": "How are you ?", "user": "agent"},
        {"text": "Nothing is working", "user": "customer"},
        {"text": "Sorry to hear this", "user": "agent"}
    ]}

If I change the event to:

{"text":"hello, this is test test, Happy sad"}

I get an error of: "{\"code\":400,\"sub_code\":\"C00012\",\"error\":\"Invalid JSON input at line 1, column 2\"}"

Here is my code:

            const AWS = require('aws-sdk');
            var http = require('https');
            exports.handler = (event, context, callback) => {
                    var text = event.text;
                    var options = {
                           method: process.env.method,
                           hostname: process.env.watson_hostname,
                           port: null,
                           path: process.env.path,
                           headers: {
                               'content-type': process.env.content_type,
                                authorization: process.env.authorization,
                               'cache-control': process.env.cache_control,
                               'X-Watson-Learning-Opt-Out': 'true'
                           }
                     };
                       var req = http.request(options, function (res) {
                       var chunks = [];
                       res.on("data", function (chunk) {
                       chunks.push(chunk);
                          });
                    res.on("end", function () { 
                           var sentimentResponse = JSON.parse(Buffer.concat(chunks));
                       console.log("Sent respose");
                        callback(null, JSON.stringify(sentimentResponse));
                   });
                   })
      req.write(text);
      req.end()
        }

Can anyone please help me, I'm new to this, and I'm stuck on this for a while now!

Thank you

Answer 1

I am a little surprised that you are not getting the same error for both inputs, as you are not actually passing in event, event.text nor text in to the http request. How you do it really depends on whether you are using a POST or a GET.

If I was to give a recommendation it would be as a POST where you would add text as part of the request body.

Amendment to answer : After your update it looks like you are using a POST. in which case you need to stringify the json. So if event.text is your json object -

let text = JSON.stringify(event.text);

For Usage see the API documentation - https://cloud.ibm.com/apidocs/tone-analyzer#analyze-general-tone