For Blog post

MockWikiHttpRequest.cls

/**
 * Author	:	Jitendra Zaa
 * Desc		:	Test class for Lightning controller WikiHttpRequest
 * */
@isTest
public class MockWikiHttpRequest implements HttpCalloutMock {
    // Implement this interface method
    public HTTPResponse respond(HTTPRequest req) { 
        // Create a fake response
        HttpResponse res = new HttpResponse();
        res.setHeader('Content-Type', 'application/json');
        res.setBody('["jitendra", ["Jitendra"], ["Jitendra may refer to:"] , ["https://en.wikipedia.org/wiki/Jitendra"] ]');
        res.setStatusCode(200);
        return res;
    }
    
    @isTest
    static void getWikiResponse_Test(){
        
        Test.setMock(HttpCalloutMock.class, new MockWikiHttpRequest());
       
        String response = WikiHttpRequest.getWikiResponse('Jitendra',1);
        
		System.assertEquals(response, 
                            '["jitendra", ["Jitendra"], ["Jitendra may refer to:"] , ["https://en.wikipedia.org/wiki/Jitendra"] ]') ;
        
    }
}