How to retrieve detail of HTTP response error

Question

I've got a node.js application that is making some https requests to a ReST web service. I want to do something that, on the face of it, appears like it should be simple - retrieve the error message that comes back from the web service.

I can get hold of the status code - i.e. 200, 404 etc but not the detail of the error.

The body of the response looks like this:

{
    "type": "http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.5",
    "title" : "Not Found",
    "status": "404",
    "detail": "Resource not found: X33003"
}

My code looks like this:

var options = {
    "method": "POST",
    "hostname": "myhost.com",
    "port": null,
    "path": "/mypath/",
    "headers": {
        "content-type": "application/json",
        "authorization": basicAuthString,
        "cache-control": "no-cache"
    }
};

try {
     var reqWorkSkill = http.request(options, function(res) {
     var chunks = [];
     res.on("data", function(chunk) {
         chunks.push(chunk);
     });
     res.on("end", function() {
         var body = Buffer.concat(chunks);             
         var response = JSON.parse(body);
         console.log("Detail: " + body.detail);  // COMES BACK UNDEFINED
     });
     res.on("error", function(error) {         
         console.log("Something went wrong with: " + resourceIdArray[i] + " failed: " + error);
     });
     if(res.statusCode != 200){
         // Do some stuff
     }
     console.log("res status: " + res.statusCode);
     console.log("res text: " + res.statusText); // COMES BACK UNDEFINED

    });
    reqWorkSkill.write(itemToPost);                       
    reqWorkSkill.end();
} 
catch (e) {
    console.log(e);
}

It would be useful to be able to present what exactly went wrong - i.e the message: Resource not found: X33003 from the JSON above. How can I get hold of that?

Answer 1

You just had the wrong properties of the objects you were calling. First, you were calling body.detail, but body was the Buffer representation. You need to call the detail property on response. Second, you were trying to get the statusTextproperty of the response, but the correct property is statusMessage. Code ends up like this:

var options = {
    "method": "POST",
    "hostname": "myhost.com",
    "port": null,
    "path": "/mypath/",
    "headers": {
        "content-type": "application/json",
        "authorization": basicAuthString,
        "cache-control": "no-cache"
    }
};

try {
     var reqWorkSkill = http.request(options, function(res) {
     var chunks = [];
     res.on("data", function(chunk) {
         chunks.push(chunk);
     });
     res.on("end", function() {
         var body = Buffer.concat(chunks);             
         var response = JSON.parse(body);
         console.log("Detail: " + response.detail);  // response, not body
     });
     res.on("error", function(error) {         
         console.log("Something went wrong with: " + resourceIdArray[i] + " failed: " + error);
     });
     if(res.statusCode != 200){
         // Do some stuff
     }
     console.log("res status: " + res.statusCode);
     console.log("res text: " + res.statusMessage); // statusMessage, not statusText

    });
    reqWorkSkill.write(itemToPost);                       
    reqWorkSkill.end();
} 
catch (e) {
    console.log(e);
}

It's always a good idea to console.log (or the equivalent) the object you're trying to access if you're not getting the correct results, that will show you all the properties of the object.