[SalesForce] RestContext.response returns null when run in Test Context

Why RestContext.response returns null when called in Test Context. Directly invoking the service do not returns null. Any workaround to execute the test without breaking the code is welcome. Its required to return a status code in the response.

@RestResource(urlMapping='/results/*') 
global with sharing class TestService{

@HttpGet 
global static void doGet() {
        RestRequest req = RestContext.request;
                RestResponse res = RestContext.response;

                // set the status code and response body for test case
                res.statusCode = 200; // Get a null pointer exception on this line
                res.responseBody = Blob.valueOf('From myRest');

}
}

Test Class :

@isTest
public class TestClass{

static testmethod testdoGet(){
  TestService.doGet();
}
}

Best Answer

You will have to set up your own RestResponse and RestRequest object.

    RestRequest req = new RestRequest(); 
    RestResponse res = new RestResponse();

    req.requestURI = 'https://na11.salesforce.com';  // sample Endpoint
    req.httpMethod = 'GET';
    RestContext.request = req;
    RestContext.response = res;

    TestService.doGet();

Look at following classes to create own payload:-

Apex has provided methods here to set up your own payload for test purpose only. However, these can be used in main class but not recommended.

Related Solutions

[SalesForce] Unexpected Null Pointer exception in testing

Are you sure you're looking at the correct line for the error? I would look at whether you're trying to access note after your conditional.

The SOQL query should always return a list, so note1 shouldn't be Null. But, if the query returned zero rows, note won't be assigned and could throw a Null Pointer Exception if you attempt to dereference it.

[SalesForce] RestResponse does not return expected statuc code in Apex Rest unit test

With the help of @Eric I finally figure out the problem. It is not related to System.runAs(). runAs() works well in the test case.

Root cause: The response from RestContext.reponse in Test Class is different from what we are getting through the Apex REST endpoint.

For example:

@RestResource(urlMapping='/MyRest/*')
global class MyRestController {
    @HttpGet
    global static String myRest() {
        RestRequest req = RestContext.request;
        RestResponse res = RestContext.response;

        return 'From myRest';
    }
}

You will get

In Apex Test:

RestResponse:[headers={}, responseBody=null, statusCode=null]

When calling the Apex REST endpoint with REST client:

Status: 200 OK Body: "From myRest"

Salesforce Apex REST helps you to return status 200 and set the response body to the return String of myRest(). However this behaviour does not reflect in RestContext.response of Apex Rest test case. You have to explicitly set it in the code if you want to test the response...

@RestResource(urlMapping='/MyRest/*')
global class MyRestController {
    @HttpGet
    global static String myRest() {
        RestRequest req = RestContext.request;
        RestResponse res = RestContext.response;

        // set the status code and response body for test case
        res.statusCode = 200;
        res.responseBody = Blob.valueOf('From myRest');

        return 'From myRest';
    }
}