after reading this article I was sure to write my own Assertions but I failed. :-(
We have an interface which looks like this:
public class ApplicationException extends RuntimeException {
public String enhancedStatus() {
return getClass().getSimpleName();
}
}
I wrote my own EnhancedStatusAssert like described in the artile.
public class EnhancedStatusAssert extends AbstractAssert<EnhancedStatusAssert, ApplicationException> {
public EnhancedStatusAssert(ApplicationException actual) {
super(actual, EnhancedStatusAssert.class);
}
public static EnhancedStatusAssert assertThat(ApplicationException actual) {
return new EnhancedStatusAssert(actual);
}
public EnhancedStatusAssert hasEnhancedCause(String enhancedStatus) {
isNotNull();
// check condition
if (!actual.enhancedStatus().equals(enhancedStatus)) {
failWithMessage("Expected enhanced status to be <%s> but was <%s>", enhancedStatus, actual.enhancedStatus());
}
return this;
}
}
Which works fine but then I have trouble to override assertThatThrownBy
assertThatThrownBy(() -> { throw new ApplicationException()})
.isInstanceOf(ApplicationException.class)
.hasEnhancedCause("cause");
What is the way to get it to run?
Thanks,
Markus
Try using asInstanceOf https://assertj.github.io/doc/#assertj-core-3.13.0-asInstanceOf you can write your own InstanceOfAssertFactory for your ApplicationException.
If you only have one field to check you can extract it with ... extracting and chain assertions on the extracted value.
Let's say I have the following classes Customer.cs, a context OfficeContext.cs, and a repository OfficeRepository.cs. Knowing that the context use a connection object, so it's advised to enclose it in a using statement:
public List<Customer> GetAllCustomersWithOrders()
{
using(var oContext = new OfficeContext())
{
//Code here....
}
}
My question is what if I want to re-use some of the code already in the repository? For instance, what if I want to display all the customers that ordered products but didn't receive them yet, do I need to duplicate the code?
public List<Customer> GetCustomersNotReceiveProducts()
{
using(var oContext = new OfficeContext())
{
//Re-use GetAllCustomersWithOrders() here???...
}
}
But as you can see, each time access a method, I also open instantiate a new context object. Is there any way to deal with that?
What I do is have my repositories implement IDisposable.
Then have two constructors (one default) that instaniates a new context that holds it as a class level variable. And another constructor that takes a context and uses that internally.
The on the dispose of the class the context is disposed (if the current repository instatiated it).
This removes the context out of the method level and moves it to the class level. My functions keep everything in IQueryable so one function can call another function and perform additional refinements before the database it hit.
Exmaple:
public class MemberRepository : IDisposable
{
OfficeContext db;
bool isExternalDb = false;
public MemberRepository()
{
db = new OfficeContext();
isExternalDb = false;
}
public MemberRepository(OfficeContext db)
{
this.db = db;
isExternalDb = true;
}
public IQueryable<Member> GetAllMembers()
{
var members= db.Members
return members;
}
public IQueryable<Member> GetActiveMembers()
{
var members = GetAllMembers();
var activeMembers = members.Where(m => m.isActive == true);
return activeMembers;
}
public void Dispose()
{
if (isExternalDb == false)
{
db.Dispose();
}
}
}
Then where I use the repository, I do a using at that level:
using(var memberRepository = new MemberRepository())
{
var members = memberRepository.GetActiveMembers();
}
Could anyone help me in assessing why the code below doesn't work. I'm using the common extension method for implementing Include when using IObjectset. In our repositories we were seeing this not returning correctly so I've isolated the code in test app as below. I've also included the interface based Context if this may prove relevant and a screenshot of the relevant model section. This occurs for all Includes on IObjectSet properties not just the DPASelections one I've chosen for this example.
If I update the context to return ObjectSet (still using the POCO entities) rather than IObjectSet it all works fine. When using IObjectSet and the extension method and step through the code I see that the extension method is completing correctly with a call to the ObjectQuery we're casting to but the included entities are never returned on the graph. As said, this works perfectly when I don't interface out the Context and return ObjectSet properties hence calling Include directly on ObjectSet.
I'm not getting any errors on executing the query so this isn't the same as several other questions on SO which refer to compiled queries.
Has anyone else experienced problems with this extension method implementation or can anyone spot what I'm doing wrong here?
Any help very much appreciated.
static void Main(string[] args)
{
using (var context = new AssocEntities())
{
context.ContextOptions.LazyLoadingEnabled = false;
Candidate candidate = context.Candidates
.Include("DPASelections.DPAOption")
.SingleOrDefault(c => c.Number == "N100064");
//Count is 0 when using ext. method and IObjectSet through AssocContext but correct when using Include
//on ObjectSet through AssocContext
Console.WriteLine("DPASelection count = {0}",candidate.DPASelections.Count);
//This is always null when using IObjectSet and ext. method but populated
//when using Include on ObjectSet
var option = candidate.DPASelections.First().DPAOption;
Console.WriteLine("First DPAOption = {0} : {1}",option.Id,option.Text);
}
Console.ReadLine();
}
}
public static class Extensions
{
public static IQueryable<TSource> Include<TSource>(this IQueryable<TSource> source, string path)
{
var objectQuery = source as ObjectQuery<TSource>;
if (objectQuery != null)
{
objectQuery.Include(path);
}
return source;
}
}
//Subset of custom context implementing IObjectSet as returns.
//Works fine when I return ObjectSet rather than IObjectSet and use
//the Include method directly
public partial class AssocEntities : ObjectContext
{
public const string ConnectionString = "name=AssocEntities";
public const string ContainerName = "AssocEntities";
#region Constructors
public AssocEntities()
: base(ConnectionString, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
public AssocEntities(string connectionString)
: base(connectionString, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
public AssocEntities(EntityConnection connection)
: base(connection, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
#endregion
#region IObjectSet Properties
public IObjectSet<Address> Addresses
{
get { return _addresses ?? (_addresses = CreateObjectSet<Address>("Addresses")); }
}
private IObjectSet<Address> _addresses;
public IObjectSet<Answer> Answers
{
get { return _answers ?? (_answers = CreateObjectSet<Answer>("Answers")); }
}
private IObjectSet<Answer> _answers;
public IObjectSet<Candidate> Candidates
{
get { return _candidates ?? (_candidates = CreateObjectSet<Candidate>("Candidates")); }
}
}
And the model...
I needed to replace objectQuery.Include(path); with objectQuery = objectQuery.Include(path);
In .Net framework 4.0 there is a build-in Extentionmethod for Include
just add the System.Data.Entity namespace.
It uses reflection - here is how it works:
private static T CommonInclude<T>(T source, string path)
{
MethodInfo method = source.GetType().GetMethod("Include", DbExtensions.StringIncludeTypes);
if (!(method != (MethodInfo) null) || !typeof (T).IsAssignableFrom(method.ReturnType))
return source;
return (T) method.Invoke((object) source, new object[1]
{
(object) path
});
}
I am loading an IronPython script from a database and executing it. This works fine for simple scripts, but imports are a problem. How can I intercept these import calls and then load the appropriate scripts from the database?
EDIT: My main application is written in C# and I'd like to intercept the calls on the C# side without editing the Python scripts.
EDIT: From the research I've done, it looks like creating your own PlatformAdaptationLayer is the way you're supposed to to implement this, but it doesn't work in this case. I've created my own PAL and in my testing, my FileExsists method gets called for every import in the script. But for some reason it never calls any overload of the OpenInputFileStream method. Digging through the IronPython source, once FileExists returns true, it tries to locate the file itself on the path. So this looks like a dead end.
After a great deal of trial and error, I arrived at a solution. I never managed to get the PlatformAdaptationLayer approach to work correctly. It never called back to the PAL when attempting to load the modules.
So what I decided to do was replace the built-in import function by using the SetVariable method as shown below (Engine and Scope are protected members exposing the ScriptEngine and ScriptScope for the parent script):
delegate object ImportDelegate(CodeContext context, string moduleName, PythonDictionary globals, PythonDictionary locals, PythonTuple tuple);
protected void OverrideImport()
{
ScriptScope scope = IronPython.Hosting.Python.GetBuiltinModule(Engine);
scope.SetVariable("__import__", new ImportDelegate(DoDatabaseImport));
}
protected object DoDatabaseImport(CodeContext context, string moduleName, PythonDictionary globals, PythonDictionary locals, PythonTuple tuple)
{
if (ScriptExistsInDb(moduleName))
{
string rawScript = GetScriptFromDb(moduleName);
ScriptSource source = Engine.CreateScriptSourceFromString(rawScript);
ScriptScope scope = Engine.CreateScope();
Engine.Execute(rawScript, scope);
Microsoft.Scripting.Runtime.Scope ret = Microsoft.Scripting.Hosting.Providers.HostingHelpers.GetScope(scope);
Scope.SetVariable(moduleName, ret);
return ret;
}
else
{ // fall back on the built-in method
return IronPython.Modules.Builtin.__import__(context, moduleName);
}
}
Hope this helps someone!
I was just trying to do the same thing, except I wanted to store my scripts as embedded resources. I'm creating a library that is a mixture of C# and IronPython and wanted to distribute it as a single dll. I wrote a PlatformAdaptationLayer that works, it first looks in the resources for the script that's being loaded, but then falls back to the base implementation which looks in the filesystem. Three parts to this:
Part 1, The custom PlatformAdaptationLayer
namespace ZenCoding.Hosting
{
internal class ResourceAwarePlatformAdaptationLayer : PlatformAdaptationLayer
{
private readonly Dictionary<string, string> _resourceFiles = new Dictionary<string, string>();
private static readonly char Seperator = Path.DirectorySeparatorChar;
private const string ResourceScriptsPrefix = "ZenCoding.python.";
public ResourceAwarePlatformAdaptationLayer()
{
CreateResourceFileSystemEntries();
}
#region Private methods
private void CreateResourceFileSystemEntries()
{
foreach (string name in Assembly.GetExecutingAssembly().GetManifestResourceNames())
{
if (!name.EndsWith(".py"))
{
continue;
}
string filename = name.Substring(ResourceScriptsPrefix.Length);
filename = filename.Substring(0, filename.Length - 3); //Remove .py
filename = filename.Replace('.', Seperator);
_resourceFiles.Add(filename + ".py", name);
}
}
private Stream OpenResourceInputStream(string path)
{
string resourceName;
if (_resourceFiles.TryGetValue(RemoveCurrentDir(path), out resourceName))
{
return Assembly.GetExecutingAssembly().GetManifestResourceStream(resourceName);
}
return null;
}
private bool ResourceDirectoryExists(string path)
{
return _resourceFiles.Keys.Any(f => f.StartsWith(RemoveCurrentDir(path) + Seperator));
}
private bool ResourceFileExists(string path)
{
return _resourceFiles.ContainsKey(RemoveCurrentDir(path));
}
private static string RemoveCurrentDir(string path)
{
return path.Replace(Directory.GetCurrentDirectory() + Seperator, "").Replace("." + Seperator, "");
}
#endregion
#region Overrides from PlatformAdaptationLayer
public override bool FileExists(string path)
{
return ResourceFileExists(path) || base.FileExists(path);
}
public override string[] GetFileSystemEntries(string path, string searchPattern, bool includeFiles, bool includeDirectories)
{
string fullPath = Path.Combine(path, searchPattern);
if (ResourceFileExists(fullPath) || ResourceDirectoryExists(fullPath))
{
return new[] { fullPath };
}
if (!ResourceDirectoryExists(path))
{
return base.GetFileSystemEntries(path, searchPattern, includeFiles, includeDirectories);
}
return new string[0];
}
public override bool DirectoryExists(string path)
{
return ResourceDirectoryExists(path) || base.DirectoryExists(path);
}
public override Stream OpenInputFileStream(string path)
{
return OpenResourceInputStream(path) ?? base.OpenInputFileStream(path);
}
public override Stream OpenInputFileStream(string path, FileMode mode, FileAccess access, FileShare share)
{
return OpenResourceInputStream(path) ?? base.OpenInputFileStream(path, mode, access, share);
}
public override Stream OpenInputFileStream(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize)
{
return OpenResourceInputStream(path) ?? base.OpenInputFileStream(path, mode, access, share, bufferSize);
}
#endregion
}
}
You would need to change the constant ResourceScriptsPrefix to whatever your base namespace is where you stored the python scripts.
Part 2, The custom ScriptHost
namespace ZenCoding.Hosting
{
internal class ResourceAwareScriptHost : ScriptHost
{
private readonly PlatformAdaptationLayer _layer = new ResourceAwarePlatformAdaptationLayer();
public override PlatformAdaptationLayer PlatformAdaptationLayer
{
get { return _layer; }
}
}
}
Part 3, finally, how to get a Python engine using your custom stuff:
namespace ZenCoding.Hosting
{
internal static class ResourceAwareScriptEngineSetup
{
public static ScriptEngine CreateResourceAwareEngine()
{
var setup = Python.CreateRuntimeSetup(null);
setup.HostType = typeof(ResourceAwareScriptHost);
var runtime = new ScriptRuntime(setup);
return runtime.GetEngineByTypeName(typeof(PythonContext).AssemblyQualifiedName);
}
}
}
It would be easy to change this to load scripts from some other location, like a database. Just change the OpenResourceStream, ResourceFileExists and ResourceDirectoryExists methods.
Hope this helps.
You can re-direct all I/O to the database using the PlatformAdaptationLayer. To do this you'll need to implement a ScriptHost which provides the PAL. Then when you create the ScriptRuntime you set the HostType to your host type and it'll be used for the runtime. On the PAL you then override OpenInputFileStream and return a stream object which has the content from the database (you could just use a MemoryStream here after reading from the DB).
If you want to still provide access to file I/O you can always fall back to FileStream's for "files" you can't find.
You need to implement import hooks. Here's an SO question with pointers: PEP 302 Example: New Import Hooks
public class Temp
{
List<T> values = new List<T>;
static Temp()
{
System.Console.WriteLine("static constructor");
}
public Temp()
{
System.Console.WriteLine("general constructor");
}
}
Also please explain me when will the List object will be created and with what type it is created.
}
It appears the field gets initialized first, then the static constructor is called, then the constructor.
class Test
{
string variable = new Func<string>(() =>
{
Console.WriteLine("field initializer");
return "VARIABLE";
})();
static string staticvariable = new Func<string>(() =>
{
Console.WriteLine("static field initializer");
return "STATICVARIABLE";
})();
static Test()
{
System.Console.WriteLine("static constructor");
}
public Test()
{
System.Console.WriteLine("general constructor");
}
}
Test t = new Test();
outuput:
static field initializer
static constructor
field initializer
general constructor
[edit]
Oops sorry, it was a non-static field and I didn't notice it.
The static ctor will be called first.
Then values list will be second and the the ctor.
Read about beforefieldinit here.