Is it possible to get the values for a TestCaseAttribute from an external data source such as an Excel Spreadsheet, CSV file or Database? i.e. Have a .csv file with 1 row of data per test case and pass that data to NUnit one at a time.
Here's the specific situation that I'd like to use this for. I'm currently merging some features from one system into another. This is pretty much just a copy and paste process from the old system into the new one. Unfortunately, the code being moved not only does not have any tests, but is not written in a testable manner (i.e. tightly coupled with the database and other code.) Taking the time to make the code testable isn't really possible since its a big mess, i'm on a tight schedule and the entire feature is scheduled to be re-written from the ground up in the next 6-9 months. However, since I don't like the idea of not having any tests around the code, I'm going to create some simple Selenium tests using WebDriver to test the page through the UI. While this is not ideal, it's better than nothing.
The page in question has about 10 input values and about 20 values that I need to assert against after the calculations are completed, with about 30 valid combinations of values that I'd like to test. I already have the data in a spreadsheet so it'd be nice to simply be able to pull that out rather than having to re-type it all in Visual Studio.
I was finally able to accomplish what I wanted using NUnit's TestCaseSource attribute. The code looks a little ugly but it works.
Here is an example of pullind the data from a .csv file and passing it to the test method. The test is for the Add method of a simple calculator that takes two ints, adds them together and returns the sum.
Class to load the test data from the file.
public class TestData
{
public int number1 { get; set; }
public int number2 { get; set; }
public int sum { get; set; }
public static IEnumerable TestCases
{
get
{
string inputLine;
using(FileStream inputStream =
new FileStream("C:\\Code\\TestData\\TestData.csv",
FileMode.Open,
FileAccess.Read))
{
StreamReader streamReader = new StreamReader(inputStream);
while((inputLine = streamReader.ReadLine()) != null)
{
var data = inputLine.Split(',');
yield return new TestData {
number1 = Convert.ToInt32(data[0])
,number2 = Convert.ToInt32(data[1])
,sum = Convert.ToInt32(data[2])
};
}
streamReader.Close();
inputStream.Close();
}
}
}
}
Class with the actual tests:
[TestFixture]
public class CalculatorTests
{
[Test]
[TestCaseSource(typeof(TestData), "TestCases")]
public void AddTwoNumbers(TestData data)
{
int sum = Calculator.Add(data.number1, data.number2);
sum.ShouldEqual(data.sum);
}
}
Contents of TestData.csv
4,4,8
15,20,35
8,8,16
5,5,10
42,13,55
It should be fairly simple to modify the get property in the TestData class to pull data from any datasource you want (i.e. Database, Web Service, Excel...)
You could always open your csv file in excel or any spreadsheet tool and then add a new column that concatenates the input/output values into the test case syntax.
Something like: =CONCATENATE("[TestCase(", A1, ",", B1, ",", C1, ",", D1, ",", E1, ")]")
Then copy/paste the column into the code.
Related
With the help of other Stackoverflow users, I have gone some way to my solution but have come to a halt.
I would like to build some generic classes in an app_code .cshtml file eg one would be to return property values from documents from a function eg
public static string docFieldValue(int docID,string strPropertyName){
var umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
var strValue = "";
try{
strValue = umbracoHelper.Content(docID).GetPropertyValue(strPropertyName).ToString();
}
catch(Exception ex){
strValue = "Error - invalid document field name (" + strPropertyName + ")";
}
var nContent = new HtmlString(strValue);
return nContent;
}
This works ok for returning one field (ie property) from a document. However, if I wanted to return 2 or more, ideally, I would store the returned node in a variable or class and then be able to fetch property values repeatedly without having to look up the document with each call
ie without calling
umbracoHelper.Content(docID).GetPropertyValue(strPropertyName).ToString();
with different strPropertyName parameters each time, as I assume that will mean multiple reads from the database).
I tried to build a class, with its properties to hold the returned node
using Umbraco.Web;
using Umbraco.Core.Models;
...
public static Umbraco.Web.UmbracoHelper umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
public static IPublishedContent docNode;
...
docNode = umbracoHelper.Content(docID);
but this crashed the code. Can I store the node in a property on a class, and if so, what type is it?
First of all, using a .cshtml file is unnecessary, use a .cs file instead :-) CSHTML files are for Razor code and HTML and stuff, CS files are for "pure" C#. That might also explain why your last idea crashes.
Second of all, UmbracoHelper uses Umbracos own cache, which means that the database is NOT touched with every request. I would at least define the umbracoHelper object outside of the method (so it gets reused every time the method is called instead of reinitialised).
Also, beware that property values can contain all kinds of other object types than strings.
EDIT
This is an example of the entire class file - my example namespace is Umbraco7 and my example class name is Helpers:
using Umbraco.Web;
namespace Umbraco7
{
public class Helpers
{
private static UmbracoHelper umbracoHelper = new UmbracoHelper(UmbracoContext.Current);
private static dynamic docNode;
public static string docFieldValue(int docID, string strPropertyName)
{
docNode = umbracoHelper.Content(docID);
return docNode.GetPropertyValue(strPropertyName).ToString();
}
}
}
This is an example how the function is called inside a View (.cshtml file inside Views folder):
#Helpers.docFieldValue(1076, "introduction")
Helpers, again, is the class name I chose. It can be "anything" you want. I've just tested this and it works.
I suggest you read up on general ASP.NET MVC and Razor development, since this is not very Umbraco specific.
I have a base object, that contains a Version property, marked as ConcurrencyCheck
public class EntityBase : IEntity, IConcurrencyEnabled
{
public int Id { get; set; }
[ConcurrencyCheck]
[Timestamp]
public byte[] Version { get; set; }
}
This works, however, I want to write a test to ensure it doesn't get broken. Unfortunately, I can't seem to figure out how to write a test that doesn't rely on the physical database!
And the relevant test code that works, but uses the database...
protected override void Arrange()
{
const string asUser = "ConcurrencyTest1"; // used to anchor and lookup this test record in the db
Context1 = new MyDbContext();
Context2 = new MyDbContext();
Repository1 = new Repository<FooBar>(Context1);
Repository2 = new Repository<FooBar>(Context2);
UnitOfWork1 = new UnitOfWork(Context1);
UnitOfWork2 = new UnitOfWork(Context2);
Sut = Repository1.Find(x => x.CreatedBy.Equals(asUser)).FirstOrDefault();
if (Sut == null)
{
Sut = new FooBar
{
Name = "Concurrency Test"
};
Repository1.Insert(Sut);
UnitOfWork1.SaveChanges(asUser);
}
ItemId = Sut.Id;
}
protected override void Act()
{
_action = () =>
{
var item1 = Repository1.FindById(ItemId);
var item2 = Repository2.FindById(ItemId);
item1.Name = string.Format("Changed # {0}", DateTime.Now);
UnitOfWork1.SaveChanges("test1");
item2.Name = string.Format("Conflicting Change # {0}", DateTime.Now);
UnitOfWork2.SaveChanges("test2"); //Should throw DbUpdateConcurrencyException
};
}
[TestMethod]
[ExpectedException(typeof(DbUpdateConcurrencyException))]
public void Assert()
{
_action();
}
How can I remove the DB requirement???
I would recommend extracting your MyDbContext into an interface IMyDbContext, and then creating a TestDbContext class that will also implement SaveChanges the way you have it up there, except with returning a random value (like 1) instead of actually saving to the database.
At that point then all you'd need to do is to test that, in fact, all of the entities got their version number upped.
Or you could also do the examples found here or here, as well.
EDIT: I actually just found a direct example with using TimeStamp for concurrency checks on this blog post.
It's my opinion that you should not try to mock this behaviour to enable "pure" unit testing. For two reasons:
it requires quite a lot of code that mocks database behaviour: materializing objects in a way that they have a version value, caching the original objects (to mock a store), modifying the version value when updating, comparing the version values with the original ones, throwing an exception when a version is different, and maybe more. All this code is potentially subject to bugs and, worse, may differ slightly from what happens in reality.
you'll get trapped in circular reasoning: you write code specifically for unit tests and then... you write unit tests to test this code. Green tests say everything is OK, but essential parts of application code are not covered.
This is only one of the many aspects of linq to entities that are hard (impossible) to mock. I am compiling a list of these differences here.
This is more a solution / work around than an actual question. I'm posting it here since I couldn't find this solution on stack overflow or indeed after a lot of Googling.
The Problem:
I have an MVC 3 webapp using EF 4 code first that I want to write unit tests for. I'm also using NCrunch to run the unit tests on the fly as I code, so I'd like to avoid backing onto an actual database here.
Other Solutions:
IDataContext
I've found this the most accepted way to create an in memory datacontext. It effectively involves writing an interface IMyDataContext for your MyDataContext and then using the interface in all your controllers. An example of doing this is here.
This is the route I went with initially and I even went as far as writing a T4 template to extract IMyDataContext from MyDataContext since I don't like having to maintain duplicate dependent code.
However I quickly discovered that some Linq statements fail in production when using IMyDataContext instead of MyDataContext. Specifically queries like this throw a NotSupportedException
var siteList = from iSite in MyDataContext.Sites
let iMaxPageImpression = (from iPage in MyDataContext.Pages where iSite.SiteId == iPage.SiteId select iPage.AvgMonthlyImpressions).Max()
select new { Site = iSite, MaxImpressions = iMaxPageImpression };
My Solution
This was actually quite simple. I simply created a MyInMemoryDataContext subclass to MyDataContext and overrode all the IDbSet<..> properties as below:
public class InMemoryDataContext : MyDataContext, IObjectContextAdapter
{
/// <summary>Whether SaveChanges() was called on the DataContext</summary>
public bool SaveChangesWasCalled { get; private set; }
public InMemoryDataContext()
{
InitializeDataContextProperties();
SaveChangesWasCalled = false;
}
/// <summary>
/// Initialize all MyDataContext properties with appropriate container types
/// </summary>
private void InitializeDataContextProperties()
{
Type myType = GetType().BaseType; // We have to do this since private Property.Set methods are not accessible through GetType()
// ** Initialize all IDbSet<T> properties with CollectionDbSet<T> instances
var DbSets = myType.GetProperties().Where(x => x.PropertyType.IsGenericType && x.PropertyType.GetGenericTypeDefinition() == typeof(IDbSet<>)).ToList();
foreach (var iDbSetProperty in DbSets)
{
var concreteCollectionType = typeof(CollectionDbSet<>).MakeGenericType(iDbSetProperty.PropertyType.GetGenericArguments());
var collectionInstance = Activator.CreateInstance(concreteCollectionType);
iDbSetProperty.SetValue(this, collectionInstance,null);
}
}
ObjectContext IObjectContextAdapter.ObjectContext
{
get { return null; }
}
public override int SaveChanges()
{
SaveChangesWasCalled = true;
return -1;
}
}
In this case my CollectionDbSet<> is a slightly modified version of FakeDbSet<> here (which simply implements IDbSet with an underlying ObservableCollection and ObservableCollection.AsQueryable()).
This solution works nicely with all my unit tests and specifically with NCrunch running these tests on the fly.
Full Integration Tests
These Unit tests test all the business logic but one major downside is that none of your LINQ statements are guaranteed to work with your actual MyDataContext. This is because testing against an in memory data context means you're replacing the Linq-To-Entity provider but a Linq-To-Objects provider (as pointed out very well in the answer to this SO question).
To fix this I use Ninject within my unit tests and setup InMemoryDataContext to bind instead of MyDataContext within my unit tests. You can then use Ninject to bind to an actual MyDataContext when running the integration tests (via a setting in the app.config).
if(Global.RunIntegrationTest)
DependencyInjector.Bind<MyDataContext>().To<MyDataContext>().InSingletonScope();
else
DependencyInjector.Bind<MyDataContext>().To<InMemoryDataContext>().InSingletonScope();
Let me know if you have any feedback on this however, there are always improvements to be made.
As per my comment in the question, this was more to help others searching for this problem on SO. But as pointed out in the comments underneath the question there are quite a few other design approaches that would fix this problem.
I'm in the process of building the capability for a user to perform ad-hoc queries on a SQL Server database. The resulting query will take on the following basic form:
SELECT <ONE TO MANY USER SELECTED FIELDS>
FROM <ONE TO MANY TABLES DETERMINED BY FIELDS SELECTED BY USER>
WHERE <ZERO TO MANY CRITERIA FOR THE SELECTED FIELDS>
It's a guarantee that the selection will most likely span more than one table.
Some (not all) of the fields may have 0 or more filter criteria for a particular field.
My application is using the default EF4 classes within ASP.NET MVC 2 using C#. I am currently passing in an object called QueryItem that contains all the information for a particular criteria.
My question(s) are:
What is the best approach for coding this? (Code samples of what I have to date below).
Can this be done with Linq2SQL or should I use ADO.NET(My current approach)
If ADO.NET is the best way, how do you access the DBConnection within EF4?
Note: I intend to refactor this into SQLParameter objects, to protect against SQL injection. My goal right now is best practice in developing the query first.
QueryItem class:
public class QueryItem
{
public bool IsIncluded { get; set; }
public bool IsRequired { get; set; }
public string LabelText { get; set; }
public string DatabaseLoc { get; set; }
public List<string> SelectedValue { get; set; }
public List<SelectListItem> SelectList { get; set; }
}
Query Parsing Code
foreach(QueryItem qi in viewModel.StandardQueryItems)
{
string[] dLoc = qi.DatabaseLoc.Split(new Char[] { '.' }); //Split the table.fieldname value into a string array
if(qi.IsIncluded == true) //Check if the field is marked for inclusion in the final query
{
fields.Append(qi.DatabaseLoc + ","); //Append table.fieldname to SELECT statement
if(!tables.ToString().Contains(dLoc[0])) // Confirm that the table name has not already been added to the FROM statement
{
tables.Append(dLoc[0] + ","); //Append the table value to the FROM statement
}
}
if(qi.SelectedValue != null)
{
if(qi.SelectedValue.Count == 1)
{
query.Append(qi.DatabaseLoc + " = '" + qi.SelectedValue[0].ToString() + "'");
}
else
{
foreach(string s in qi.SelectedValue)
{
//Needs to handle "IN" case properly
query.Append(qi.DatabaseLoc + " IN " + qi.SelectedValue.ToString());
}
}
}
}
I have built a similar system to what you are describing in the past by passing in a single parameter to a stored procedure of type xml. By doing so, you can actually specify(in xml), what all you would like to report off of and build the SQL necessary to return the results you want.
This also makes your C# code easier, as all you have to do is generate some xml that your procedure will read. Generating Dynamic SQL is definitely not something you should use unless you have to, but when you want to allow users to dynamically select what they want to report off of, it's pretty much the only way to go about doing it.
Another option for you might be to look into Reporting Services - that will allow the user to pick what fields they want to view and save that particular 'report' in their own section where they can then go back and run it again at any time.. You could also create the reports for them if they aren't computer savvy(which is a lot easier to do with report builder, provided that all they need is data and no special features).
Either way you go about it, their are pros and cons to both solutions.. You'll have to determine which option is best for you.
xml/dynamic sql: Hard to maintain/make changes to.(I feel sorry for anyone who has to come behind someone who is generating dynamic sql and try to understand the logic behind the mess).
reporting services: very easy to spit out reports that look good, but it's a little less flexible and it's not free.
I'm using the NUnit 2.5.3 TestCaseSource attribute and creating a factory to generate my tests. Something like this:
[Test, TestCaseSource(typeof(TestCaseFactories), "VariableString")]
public void Does_Pass_Standard_Description_Tests(string text)
{
Item obj = new Item();
obj.Description = text;
}
My source is this:
public static IEnumerable<TestCaseData> VariableString
{
get
{
yield return new TestCaseData(string.Empty).Throws(typeof(PreconditionException))
.SetName("Does_Reject_Empty_Text");
yield return new TestCaseData(null).Throws(typeof(PreconditionException))
.SetName("Does_Reject_Null_Text");
yield return new TestCaseData(" ").Throws(typeof(PreconditionException))
.SetName("Does_Reject_Whitespace_Text");
}
}
What I need to be able to do is to add a maximum length check to the Variable String, but this maximum length is defined in the contracts in the class under test. In our case its a simple public struct:
public struct ItemLengths
{
public const int Description = 255;
}
I can't find any way of passing a value to the test case generator. I've tried static shared values and these are not picked up. I don't want to save stuff to a file, as then I'd need to regenerate this file every time the code changed.
I want to add the following line to my testcase:
yield return new TestCaseData(new string('A', MAX_LENGTH_HERE + 1))
.Throws(typeof(PreconditionException));
Something fairly simple in concept, but something I'm finding impossible to do. Any suggestions?
Change the parameter of your test as class instead of a string. Like so:
public class StringTest {
public string testString;
public int maxLength;
}
Then construct this class to pass as an argument to TestCaseData constructor. That way you can pass the string and any other arguments you like.
Another option is to make the test have 2 arguments of string and int.
Then for the TestCaseData( "mystring", 255). Did you realize they can have multiple arguments?
Wayne
I faced a similar problem like yours and ended up writing a small NUnit addin and a custom attribute that extends the NUnit TestCaseSourceAttribute. In my particular case I wasn't interested in passing parameters to the factory method but you could easily use the same technique to achieve what you want.
It wasn't all that hard and only required me to write something like three small classes. You can read more about my solution at: blackbox testing with nunit using a custom testcasesource.
PS. In order to use this technique you have to use NUnit 2.5 (at least) Good luck.