Lambda - Make an HTTPS request blueprint - not working

Question

I'm attempting to use the Lambda Make an HTTPS request blueprint as a starting point to request a JSON response from an API.

![function from blueprint](/media/postImages/original/IMtdS5GfrIR0G-A96Q870V2A)

After I created the function I set up a test event. With something like the following.

{
  "options": {
    "headers": {
      "Authorization": "Bearer key-here"
    },
    "host": "my.host.here",
    "path": "/my/path/here"
  }
}

I can't share the actual values as the API requires a key. I have no trouble using CURL or Postman to make a call to the API so I know the API works.

When I test the function I get the following error.

Response
{
  "errorType": "TypeError",
  "errorMessage": "The \"chunk\" argument must be of type string or an instance of Buffer or Uint8Array. Received undefined",
  "trace": [
    "TypeError [ERR_INVALID_ARG_TYPE]: The \"chunk\" argument must be of type string or an instance of Buffer or Uint8Array. Received undefined",
    "    at new NodeError (node:internal/errors:405:5)",
    "    at write_ (node:_http_outgoing:875:11)",
    "    at ClientRequest.write (node:_http_outgoing:834:15)",
    "    at Runtime.handler (file:///var/task/index.mjs:42:9)",
    "    at Runtime.handleOnceNonStreaming (file:///var/runtime/index.mjs:1173:29)"
  ]
}

Function Logs
START RequestId: 1e79244e-1d9a-42fd-baf6-b91179268805 Version: $LATEST
2024-04-21T00:16:37.425Z	1e79244e-1d9a-42fd-baf6-b91179268805	ERROR	Invoke Error 	{"errorType":"TypeError","errorMessage":"The \"chunk\" argument must be of type string or an instance of Buffer or Uint8Array. Received undefined","code":"ERR_INVALID_ARG_TYPE","stack":["TypeError [ERR_INVALID_ARG_TYPE]: The \"chunk\" argument must be of type string or an instance of Buffer or Uint8Array. Received undefined","    at new NodeError (node:internal/errors:405:5)","    at write_ (node:_http_outgoing:875:11)","    at ClientRequest.write (node:_http_outgoing:834:15)","    at Runtime.handler (file:///var/task/index.mjs:42:9)","    at Runtime.handleOnceNonStreaming (file:///var/runtime/index.mjs:1173:29)"]}
END RequestId: 1e79244e-1d9a-42fd-baf6-b91179268805
REPORT RequestId: 1e79244e-1d9a-42fd-baf6-b91179268805	Duration: 216.36 ms	Billed Duration: 217 ms	Memory Size: 128 MB	Max Memory Used: 69 MB	Init Duration: 192.81 ms

Instead of using the test event I created an option constant and replaced event.options in the code to bypass possible errors in my test event JSON. Still got the chunk error.

I even tried a string with URL to an API I know that works, needs no authorization, and used that as the first parameter to https.request. No joy.

Can someone try the blueprint and show me test event JSON that works for an API you know that is open? I can usually work from a working example.

Thanks for any help.

Accepted Answer

Hello.

I'm not sure what kind of code your Lambda function has, but if you keep the default code, I think you can make a request with the event JSON below.  
Even if there is no need to include a body in the request, we specify an empty field by including ""data": {},".  
```
{
  "data": {},
  "options": {
    "hostname": "www.google.com"
  }
}
```

The code below is generated by Lambda by default, but uses "data" in "req.write(JSON.stringify(event.data));".  
```
import * as https from 'node:https';

/**
 * Pass the data to send as `event.data`, and the request options as
 * `event.options`. For more information see the HTTPS module documentation
 * at https://nodejs.org/api/https.html.
 *
 * Will succeed with the response body.
 */
export const handler = (event, context, callback) => {
    const req = https.request(event.options, (res) => {
        let body = '';
        console.log('Status:', res.statusCode);
        console.log('Headers:', JSON.stringify(res.headers));
        res.setEncoding('utf8');
        res.on('data', (chunk) => body += chunk);
        res.on('end', () => {
            console.log('Successfully processed HTTPS response');
            // If we know it's JSON, parse it
            if (res.headers['content-type'] === 'application/json') {
                body = JSON.parse(body);
            }
            callback(null, body);
        });
    });
    req.on('error', callback);
    req.write(JSON.stringify(event.data));
    req.end();
};
```

Lambda - Make an HTTPS request blueprint - not working

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