Salesforce trailhead - Apex-Integration-Services-Apex-REST-Callouts

AnimalLocator.cls

public class AnimalLocator {
	public class cls_animal {
		public Integer id;	
		public String name;	
		public String eats;	
		public String says;	
	}    
public class JSONOutput{
	public cls_animal animal;

   	//public JSONOutput parse(String json){
	//return (JSONOutput) System.JSON.deserialize(json, JSONOutput.class);
	//}
}
    
    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.setHeader('id', String.valueof(id)); -- cannot be used in this challenge :)
        request.setMethod('GET');
        HttpResponse response = http.send(request);
        system.debug('response: ' + response.getBody());
        //Map<String,Object> map_results = (Map<String,Object>) JSON.deserializeUntyped(response.getBody());
        jsonOutput results = (jsonOutput) JSON.deserialize(response.getBody(), jsonOutput.class);
        //Object results = (Object) map_results.get('animal');
		system.debug('results= ' + results.animal.name);
        return(results.animal.name);
    }

}

AnimalLocatorMock

@IsTest
global class AnimalLocatorMock implements HttpCalloutMock {
    
    global HTTPresponse respond(HTTPrequest request) {
        Httpresponse response = new Httpresponse();
        response.setStatusCode(200);
        //-- directly output the JSON, instead of creating a logic
        //response.setHeader('key, value)
        //Integer id = Integer.valueof(request.getHeader('id'));
        //Integer id = 1;
        //List<String> lst_body = new List<String> {'majestic badger', 'fluffy bunny'};
        //system.debug('animal return value: ' + lst_body[id]);
        response.setBody('{"animal":{"id":1,"name":"chicken","eats":"chicken food","says":"cluck cluck"}}');
        return response;
    }

}

AnimalLocatorTest.cls

@IsTest
public class AnimalLocatorTest {
    @isTest
    public static void testAnimalLocator() {
        Test.setMock(HttpCalloutMock.class, new AnimalLocatorMock());
        //Httpresponse response = AnimalLocator.getAnimalNameById(1);
        String s =  AnimalLocator.getAnimalNameById(1);
        system.debug('string returned: ' + s);
    }

}

If you still get the error "Executing the 'getAnimalNameById' method on 'AnimalLocator' failed. Make sure the method exists with the name 'getAnimalNameById', is public and static, accepts an Integer and returns a String." and you have correctly set the remote site settings, that does not mean necessarily that the method does not exist. Check the logs after you click on "Check Challenge" you will have a better understanding of the error you made in your code. In my case, the json i have imagined wasn't the right one so my test class worked just fine with 100 % coverage but the json trailhead was expecting was different.

so whats the solution to it??I cant able to rectify it

I don't have a full explanation, but I want to point out that I got past these issues by setting up a class similar to the original poster's (OP - @mannharleen ) AnimalLocator.cls code. I believe the reason is that I was returning a single string from my mock which didn't include an object representing an animal, just the name.

res.setBody('{"name":"singing squirtle"}');

I hope this helps, and I would really appreciate if someone, possibly OP @mannharleen, could help me understand how I could have achieved the same results without creating an animal class. For reference I'll provide the code where I was attempting to do this so you may be able to just point out what's wrong.

Assume the JSON body looks like this:
{"animals" : {[{ "name" : "test animal" }]} }

Reference Code - (AnimalLocator.apxc):

public class AnimalLocator {
public static String getAnimalNameById(Integer animalId){
Http http = new Http();
HttpRequest req = new HttpRequest();

    req.setEndpoint('https://th-apex-http-callout.herokuapp.com/animals/' + animalId);
    req.setMethod('GET');
    req.setHeader('Content-Type', 'application/json;charset=UTF-8');
    
    HttpResponse res = http.send(req);
    
    Map<String, Object> jRes = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
        
   List<Object> animals = (List<Object>) jRes.get('animals');

    String animalName = (String) animals.name;
    
    return animalName;
}

}

Thank you!

I was able to complete the process by converting the JSON data into the expected format.

This does the job

`
public class AnimalLocator {
public static String getAnimalNameById(Integer id) {
String endpoint = 'https://th-apex-http-callout.herokuapp.com/animals/' + id;
HttpRequest req = new HttpRequest();
req.setEndpoint(endpoint);
req.setMethod('GET');

    Http http = new Http();
    HttpResponse res = http.send(req);
    if (res.getStatusCode() == 200) { 
        Map<String, Object> jRes = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
        Map<String, Object> animal = (Map<String, Object>) jRes.get('animal');
        String animalName = (String) animal.get('name');
        return animalName;
    } else {
        return null;
    }
}

}
`

Thank you for the post. I was able to find my error in my AnimalLocatorTest class checking against your code.