Hi,

I have written the below classes as part of the trailhead challenge for Apex REST callouts.

The class -

public class AnimalLocator {
  
  public static String getAnimalNameById(Integer id) {
    
    Http http = new Http();
    HttpRequest request = new HttpRequest();
    request.setEndpoint('https://th-apex-http-callout.herokuapp.com/animals/'+id);
    request.setMethod('GET');
    
    HttpResponse response = http.send(request);
    List<Object> animals; 
    String returnValue; 
    
    // parse the JSON response
    if (response.getStatusCode() == 200) {
      Map<String, Object> result = (Map<String, Object>) JSON.deserializeUntyped(response.getBody());
      animals = (List<Object>) result.get('animals');
      System.debug(animals);
    }
    
    if (animals.size() > 0 && animals != NULL && id < animals.size()) {
      returnValue = (String) animals.get(id);
    }
    
    return returnValue;
  } 
    
}

Mock Response Class - 

@isTest
global class AnimalLocatorMock implements HttpCalloutMock {
     // Implement this interface method
    global HTTPResponse respond(HTTPRequest request) {
        // Create a fake response
        HttpResponse response = new HttpResponse();
        response.setHeader('Content-Type', 'application/json');
        response.setBody('{"animals": ["majestic badger", "fluffy bunny", "scary bear", "chicken", "mighty moose"]}');
        response.setStatusCode(200);
        return response; 
    }
}

Test Class - 

@isTest
private class AnimalLocatorTest{
    @isTest static void AnimalLocatorMock1() {
        Test.setMock(HttpCalloutMock.class, new AnimalLocatorMock());
        string result = AnimalLocator.getAnimalNameById(3);
        String expectedResult = 'chicken';
        System.assertEquals(result,expectedResult );
    }
}

I have got 100% code coverage for the main class. But when I check the challenge I get 

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.NullPointerException: Attempt to de-reference a null object

Please tell me if any changes to the code is required. It's really frustrating as I am stuck from past 3-4 days with this unit.

Thanks & Regards,

Abhiram Sheshadri

Hi All,

I am doing Apex Rest Callouts in Trailhead Apex Integration Service Module.
https://developer.salesforce.com/trailhead/force_com_dev_intermediate/apex_integration_services/apex_integration_rest_callouts

This is AnimalLocator class.

public class AnimalLocator{
    public static String getAnimalNameById(Integer x){
        Http h = new Http();
        HttpRequest req = new HttpRequest();
        
        req.setEndpoint('https://th-apex-http-callout.herokuapp.com/animals/' + x);
        
        req.setMethod('GET');
        
        HttpResponse res = h.send(req);
        Map<String, Object> results = (Map<String, Object>)JSON.deserializeUntyped(res.getBody());
        Map<String, Object> animal = (Map<String, Object>) results.get('animal');
        return (String)animal.get('name');
    }
}

However, I was encountered this error when checking challenge.

Challenge Not yet complete... here's what's wrong: 
The Apex class does not appear to be calling the REST endpoint using HttpRequest.

I have no idea what it means, but I have call the REST endpoint.