Invalid conversion from runtime type String to Map<String,ANY> not working

Question

I have a requirement to call a external service with post method.

When i tested in anymonous block.It's working fine.

But when i try to set up test classes i got this error.

in line

Map results = (Map) JSON.deserializeUntyped(res.getBody());

            HttpRequest req = new HttpRequest();
    req.setEndpoint('https://api.incontact.com/InContactAuthorizationServer/Token');
            req.setMethod('POST');

            // Specify the required user name and password to access the endpoint
            // As well as the header and header information

            String username = 'sfintegration';
            String password = 'Test';
            String vendor   = 'Salesforce';
            String businessunit ='459';
            String application ='Callout';
            Blob headerValue = Blob.valueOf(application + '@' + vendor + ':' + 
             businessunit);
            String authorizationHeader = 'BASIC ' +
            EncodingUtil.base64Encode(headerValue);
            req.setHeader('Authorization', authorizationHeader);
            //req.setBody(str);
            // Create a new http object to send the request object
            // A response object is generated as a result of the request

            req.setHeader('Content-Type', 'application/json;charset=UTF-8');
            JSONGenerator gen = JSON.createGenerator(true);    
            gen.writeStartObject();      
            gen.writeStringField('grant_type','password');
            gen.writeStringField('username',username);
            gen.writeStringField('password',password);
            gen.writeStringField('scope','');
            gen.writeEndObject();
            String jsonS = gen.getAsString();
            system.debug('Data in gen'+jsonS);
            req.setBody(jsonS);

            // Create a new http object to send the request object
            // A response object is generated as a result of the request  

            Http http = new Http();
            HTTPResponse res = http.send(req);
            System.debug(res.getBody());
            System.debug(res.getStatusCode());

            //JSONParser parser = JSON.createParser(res.getBody());

            Map<String,Object> results = (Map<String,Object>) 
            JSON.deserializeUntyped(res.getBody());

            //System.debug('Values in results: '+results.values());
            //System.debug('Keys in list: '+results.keyset());

            accesstoken=String.valueof(results.get('access_token'));
            baseurl=String.valueof(results.get('resource_server_base_uri'));
            System.debug('Access Token:'+accesstoken);
            System.debug('baseurl: '+baseurl);
            If(accesstoken !=null && baseurl !=null)
            {
                for(Lead ts:TriggerLeads)
                {
                    String s=String.valueOf(ts.Phone);
                    RequestACallback(accesstoken,baseurl,s);
                }
            }

Please let me know where i missed it.

Answer 1

It looks like your mock response didn't setup correctly. You need to setup it correctly.

Do that and it will solve your problem.