How can i unit test the following code?
private Future<JSONArray> getData(String cqlQuery, String eventName) {
ExecutorService executor = Executors.newFixedThreadPool(1);
CqlClientCallable cqlClientCallable = new CqlClientCallable(cqlQuery,
cqlApiClient, eventName);
Future<JSONArray> cqlResultFuture = executor.submit(cqlClientCallable);
executor.shutdown();
return cqlResultFuture;
I was trying to use Mockito in the test code like mentioned below but that returned a null since myArray is declared null(as obvious).I am not able to return a non null value using Mockito.
Future<JSONArray> myArray = null;
Mockito.when(executor.submit(cqlClientCallable)).thenReturn(myArray);
Related
I am writing unit tests for my asp.net web API application and one of them is trying to verify that AddOrGetExisting is working correctly. According to the MSDN documentation, AddOrGetExisting returns an item if it's already saved, and if not it should write it into Cache.
The problem I am having is that if I add the key to MemoryCache object from an unit test, then call AddOrGetExisting, it will always return null and overwrite the value instead of returning the value that is already saved. I am verifying that the value is in the cache right before I call AddOrGetExisting(bool isIn evaluates to true).
Here is the code for my memory cache and the test method. Any help would be much appreciated:
public static class RequestCache
{
public static TEntity GetFromCache<TEntity>(string key, Func<TEntity> valueFactory) where TEntity : class
{
ObjectCache cache = MemoryCache.Default;
var newValue = new Lazy<TEntity>(valueFactory);
CacheItemPolicy policy = new CacheItemPolicy { AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(60) };
bool isIn = cache.Contains(key);
// Returns existing item or adds the new value if it doesn't exist
var value = cache.AddOrGetExisting(key, newValue, policy) as Lazy<TEntity>;
return (value ?? newValue).Value;
}
}
public string TestGetFromCache_Helper()
{
return "Test3and4Values";
}
[TestMethod]
public void TestGetFromCache_ShouldGetItem()
{
ObjectCache cache = MemoryCache.Default;
CacheItemPolicy policy = new CacheItemPolicy { AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(60) };
var cacheKey = "Test3";
var expectedValue = "Test3Value";
cache.AddOrGetExisting(cacheKey, expectedValue, policy);
var result = Models.RequestCache.GetFromCache(cacheKey,
() =>
{
return TestGetFromCache_Helper();
});
Assert.AreEqual(expectedValue, result);
}
The issue may be that you're passing a Lazy<TEntity> as newValue within RequestCache.GetFromCache but passing a string as expectedValue in the test method.
When running the test, the cache.Contains(key) confirms that there is a value stored for that key, which is true. However it is a string instead of a Lazy<TEntity>. Apparently AddOrGetExisting decides to overwrite the value in that case.
The fix for this particular scenario may be to adjust the expectedValue assignment in your test to something like this:
var expectedValue = new Lazy<string>(TestGetFromCache_Helper);
You'd also need to pull the value from the Lazy in the test's final equality comparison, for example:
Assert.AreEqual(expectedValue.Value, result);
I'm trying to verify a method call using Moq, but I can't quite get the syntax right. Currently, I've got this as my verify:
repository.Verify(x => x.ExecuteNonQuery("fav_AddFavorites", new
{
fid = 123,
inputStr = "000456"
}), Times.Once());
The code compiles, but the test fails with the error:
Expected invocation on the mock once, but was 0 times:
x => x.ExecuteNonQuery("fav_AddFavorites", new <>f__AnonymousType0<Int32, String>(123, "000456"))
No setups configured.
Performed invocations:
IRepository.ExecuteNonQuery("fav_AddFavorites", { fid = 123, inputStr = 000456 })
How can I verify the method call and match the method parameters for an anonymous type?
UPDATE
To answer the questions:
I am trying to verify both that the method was called and that the parameters are correct.
The signature of the method I'm trying to verify is:
int ExecuteNonQuery(string query, object param = null);
The setup code is simply:
repository = new Mock<IRepository>();
UPDATE 2
It looks like this is a problem with Moq and how it handles anonymous types in .Net. The code posted by Paul Matovich runs fine, however, once the code and the test are in different assemblies the test fails.
This Passes
public class Class1
{
private Class2 _Class2;
public Class1(Class2 class2)
{
_Class2 = class2;
}
public void DoSomething(string s)
{
_Class2.ExecuteNonQuery(s, new { fid = 123, inputStr = "000456" });
}
}
public class Class2
{
public virtual void ExecuteNonQuery(string s, object o)
{
}
}
/// <summary>
///A test for ExecuteNonQuery
///</summary>
[TestMethod()]
public void ExecuteNonQueryTest()
{
string testString = "Hello";
var Class2Stub = new Mock<Class2>();
Class1 target = new Class1(Class2Stub.Object);
target.DoSomething(testString);
Class2Stub.Verify(x => x.ExecuteNonQuery(testString, It.Is<object>(o => o.Equals(new { fid = 123, inputStr = "000456" }))), Times.Once());
}
##Update##
That is strange, it doesn't work in different assemblies. Someone can give us the long definition about why the object.equals from different assemblies behaves differently, but for different assemblies, this will work, any variance in the object values will return a different hash code.
Class2Stub.Verify(x => x.ExecuteNonQuery(testString, It.Is<object>(o => o.GetHashCode() == (new { fid = 123, inputStr = "000456" }).GetHashCode())), Times.Once());
One option is to "verify" it in a Callback. Obviously this needs to be done at Setup time, e.g.:
aMock.Setup(x => x.Method(It.IsAny<object>())).Callback<object>(
(p1) =>
{
dynamic o = p1;
Assert.That(o.Name, Is.EqualTo("Bilbo"));
});
None of the answers are great when your test assembly is different than the system under test's assembly (really common). Here's my solution that uses JSON serialization and then strings comparison.
Test Helper Function:
using Newtonsoft.Json;
public static class VerifyHelper
{
public static bool AreEqualObjects(object expected, object actual)
{
var expectedJson = JsonConvert.SerializeObject(expected);
var actualJson = JsonConvert.SerializeObject(actual);
return expectedJson == actualJson;
}
}
Example System Under Test:
public void DoWork(string input)
{
var obj = new { Prop1 = input };
dependency.SomeDependencyFunction(obj);
}
Example Unit Test:
var expectedObject = new { Prop1 = "foo" };
sut.DoWork("foo");
dependency.Verify(x => x.SomeDependencyFunction(It.Is<object>(y => VerifyHelper.AreEqualObjects(expectedObject, y))), Times.Once());
This solution is really simple, and I think makes the unit test easier to understand as opposed to the other answers in this thread. However, because it using simple string comparison, the test's anonymous object has to be set up exactly the same as the system under the test's anonymous object. Ergo, let's say you only cared to verify the value of a single property, but your system under test sets additional properties on the anonymous object, your unit test will need to set all those other properties (and in the same exact order) for the helper function to return true.
I created a reusable method based on Pauls answer:
object ItIsAnonymousObject(object value)
{
return It.Is<object>(o => o.GetHashCode() == value.GetHashCode());
}
...
dependency.Verify(
x => x.SomeDependencyFunction(ItIsAnonymousObject(new { Prop1 = "foo" })),
Times.Once());
Also, this can be used for property name case-insensitive comparison:
protected object ItIsAnonymousObject(object value)
{
var options = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
return It.Is<object>(o => JsonSerializer.Serialize(o, options) == JsonSerializer.Serialize(value, options));
}
I am writing test cases to test function with flexunit 4. I am using aysnc method.
But when I add two or more asyncHandlers to the instance. I meet the problem: Error: Asynchronous Event Received out of Order. How to resolve this problem? Thanks.
Code snippets:
[Test(order=1, async, description="synchronize content on line")]
public function testSynchronizeContentOnline():void
{
var passThroughData:Object = new Object();
var asyncHandler1:Function = Async.asyncHandler(this, authFailureHandler, 60000, null, timeoutHandler);
var asyncHandler:Function = Async.asyncHandler(this, authSuccessHandler, 60000, null, timeoutHandler);
caseManager.addEventListener(CaseAuthEvent.AUTH_SUCCESS,
asyncHandler);
caseManager.addEventListener(CaseAuthEvent.AUTH_FAILURE,
asyncHandler1);
caseManager.authenticate("admin", "admin");
trace('test');
}
private function timeoutHandler(event:Event):void
{
Assert.fail( "Timeout reached before event");
}
private var authFailed:Boolean = false;
private function authFailureHandler(event:CaseAuthEvent, passThroughData:Object):void
{
trace("authFailure:" + event.type);
authFailed = true;
}
private var authSucceed:Boolean = false;
private function authSuccessHandler(event:CaseAuthEvent, passThroughData:Object):void
{
trace("authSucceed:" + event.type);
authSucceed = true;
Assert.assertTrue(true);
}
That would be because you're adding order to your test cases, which is seems something else is dispatching before the first one is complete. To quote the ordering part of the flex unit wiki:
Your tests need to act independently of each other, so the point of
ordering your tests in a custom way is not to ensure that test A sets
up some state that test B needs. If this is the reason you are reading
this section, please reconsider. Tests need to be independent of each
other and generally independent of order.
Which I completely agree with. There should not be any order in your tests. The tests themselves sets the state of what needs to be done.
Your test will work if you test success and fail separately. So basically have 2 tests, one adds an async handler for your events success, the other for the events fail. Here is an example of the 2 tests as I would approach them...
[Test(async)]
public function testEventSuccess():void
{
var passThroughData:Object = new Object();
var asyncHandler:Function = Async.asyncHandler(this, authSuccessHandler, 60000, null, timeoutHandler);
caseManager.addEventListener(CaseAuthEvent.AUTH_SUCCESS,
asyncHandler);
caseManager.authenticate("admin", "admin");
}
[Test(async)]
public function testEventFailure():void
{
var passThroughData:Object = new Object();
var asyncHandler:Function = Async.asyncHandler(this, authFailureHandler, 60000, null, timeoutHandler);
caseManager.addEventListener(CaseAuthEvent.AUTH_FAILURE,
asyncHandler);
caseManager.authenticate("admin", "admin");
}
Remember to make a new instance of your caseManager in your set up function and its good practice to remove ref to it in the tearDown as the simple code snippet shows, I've just assumed the caseManager is of type CaseManager.
[Before]
public function setUp():void
{
caseManager = new CaseManager();
}
[After]
public function tearDown():void
{
caseManager = null;
}
My Question is how do I handle a null set returned from a linq query if I am loading it into a custom class.
example
queryResults = queryResults.Select(p => new specialItems(p.ID, p.SECTION, p.PROGRAM, p.EVENT).ToList<specialItems>();
...
public class specialItems
{
public string Id { get; set; }
public string Section { get; set; }
public string Program { get; set; }
public string Event { get; set; }
public courseItems(string id, string section, string program, string event)
{
this.Id = id;
this.Section = section;
this.Program = program;
this.Event = event;
}
}
Currently this query works great until the result set is empty, then I get:
"Object reference not set to an instance of an object."
I need the query to return an empty List if the result set is empty.
UPDATE - Asided from the invalid redeclaration of a variable (fixed) I did find that the issue was higher up in the initial construction of the linq query. This became apparent when I received several good suggestions and removed the error. Once I fixed the original query things worked swimmingly.
Use the null coalescing operator (??).
List<specialItems> queryResults = queryResults.Select(p => new specialItems(p.ID, p.SECTION, p.PROGRAM, p.EVENT).ToList<specialItems>() ?? new List<specialItems>();
EDIT: Yeah, looking at what you have there a little closer, it's the ToList that's blowing up when this happens. You might have to split it up a bit.
var temp = queryResults.Select(p => new specialItems(p.ID, p.SECTION, p.PROGRAM, p.EVENT);
List<specialItems> results = temp == null ? new List<specialItems>() : temp.ToList<SpecialItems>();
Have to do it this way, because there's no good spot to put the null coalescing operator in this case.
Robaticus is mostly right, use the null coalescing operator (??). Howerver, since you didn't include the stack trace, I assume your code is throwing because queryResults is initially null. By the time you get to the ?? operator, you've already thrown the exception, because you tried to dereference queryResults.
Also, the code you have doesn't make a ton of sense, because queryResults is already defined within that scope by the time you get to that line. You can't redefine a variable that has already been declared locally in that scope.
List<SpecialItems> queryResults = GetSomeResults();
queryResults = (queryResults ?? new List<SpecialItems>())
.Select(p => new SpecialItems(p.ID, p.SECTION, p.PROGRAM, p.EVENT))
.ToList<SpecialItems>();
If you can get the function or line that spits out the original version of queryResults to return an empty list instead of null, then try to do that, or coalesce the results on that line. That's probably better than having all that code on the query line :)
List<SpecialItems> queryResults = GetSomeResults() ?? new List<SpecialItems>();
queryResults = queryResults
.Select(p => new SpecialItems(p.ID, p.SECTION, p.PROGRAM, p.EVENT))
.ToList<SpecialItems>();
Linq returns an empty list if there are no results, never null. Therefore, the problem is certainly not that queryResults.Select() returns null.
What is probably going on is that we're looking at a lazily evaluated linq-to-objects 'query'. ToList() triggers the evaluation of it, and probably the nullreference exception occurs in a lambda expression higher up the chain.
Neither Enumerable.Select, nor Queryable.Select, nor Enumerable.ToList return null.
The query is not realized until ToList enumerates it. During that enumeration, a null reference exception is occuring due to code you have not posted in the question.
Consider this code with and without the commented line:
List<int> source = Enumerable.Range(1, 10).ToList();
IEnumerable<int> query = null;
try
{
query = source.Where(i => 1 / i > 0);
}
catch(Exception ex)
{
Console.WriteLine("Exception was caught {0}", ex.Message);
}
// source.Add(0);
List<int> result = query.ToList();
Consider this code with and without the commented line:
DataContext myDC = new DataContext();
string name = null;
IQueryable<Person> query = myDC.Persons.Where(p => p.Name.StartsWith(name));
// name = "Zz";
List<Person> result = query.ToList();
Given the following interface
public interface ISomething {
void DoMany(string[] strs);
void DoManyRef(ref string[] strs);
}
I would like to verify that the DoManyRef method is called, and passed any string array as the strs parameter. The following test fails:
public void CanVerifyMethodsWithArrayRefParameter() {
var a = new Mock<ISomething>().Object;
var strs = new string[0];
a.DoManyRef(ref strs);
var other = It.IsAny<string[]>();
Mock.Get(a).Verify(t => t.DoManyRef(ref other));
}
While the following not requiring the array passed by reference passes:
public void CanVerifyMethodsWithArrayParameter() {
var a = new Mock<ISomething>().Object;
a.DoMany(new[] { "a", "b" });
Mock.Get(a).Verify(t => t.DoMany(It.IsAny<string[]>()));
}
I am not able to change the interface to eliminate the by reference requirement.
For verifying against ref arguments, you need to pass the actual instance into the verify call. This means your first test should appear as follows:
[Test]
public void CanVerifyMethodsWithArrayRefParameter()
{
var a = new Mock<ISomething>().Object;
var strs = new string[0];
a.DoManyRef(ref strs);
Mock.Get(a).Verify(t => t.DoManyRef(ref strs));
}
The final sentence of the question leads me to believe you might not be able to make that change, but that is what is required for the Verify call to succeed. Hope this helps.