I am working on the eclipse plugin development,so I find the api docs and google them,it only contains such method isClass() isInterface() with the ICompilationUnit,but I want to dig deep with the abstract class,the code like
public boolean isAbstract(ICompilationUnit icu) {
//TODO
}
can anybody help me?
First, you will need an instance of org.eclipse.jdt.core.IType, because one ICompilationUnit can contain several types. ICompilationUnit.getTypes() will provide you with list of all types in this unit. ICompilationUnit.findPrimaryType() will get you a primary type for this unit.
Your routine should look something like following:
public boolean isAbstract(ICompilationUnit icu) throws JavaModelException {
final IType type = icu.findPrimaryType();
return (type != null)
? Flags.isAbstract(type.getFlags())
: false;
}
where Flags is org.eclipse.jdt.core.Flags.
Related
It seems that for some reason, Microsoft has created an interface for it's messenger and then gone and implemented the logic as extension methods on the interface itself.
Unfortunately, I cannot use this beautiful solution: http://agooddayforscience.blogspot.com/2017/08/mocking-extension-methods.html - because IMessenger extensions calls implemented code on Messenger with an internal type as argument.
Why would Microsoft go to such lengths to make unit testing hard? (If you know a good, technical reason for this, please comment with the answer. I am very curious).
I want to unit test the ViewModels, which injects IMessenger. So how do I do this?
My solution is: Wrap IMessenger in a wrapper with an interface and inject that instead.
Is there a simpler/better solution? (I want it to be easy to understand and maintain).
Moq is incredibly extensible, and provides an extension point for exactly this purpose. You can provide custom type matching logic by creating a type that implements ITypeMatcher. To match the IMessenger.Send signature, for instance:
[TypeMatcher]
public sealed class IsAnyToken : ITypeMatcher, IEquatable<IsAnyToken>
{
public bool Matches(Type typeArgument) => true;
public bool Equals(IsAnyToken? other) => throw new NotImplementedException();
}
You can use this to write Setup and Verify code exactly like It.IsAnyType:
mockMessenger.Setup(x => x.Send(It.IsAny<MyMessage>(), It.IsAny<IsAnyToken>());
...
mockMessenger.Verify(x => x.Send(It.IsAny<MyMessage>(), It.IsAny<IsAnyToken>(), Times.Once);
Wrapping the interface (as others have suggested) is certainly an answer, but I don't like the cognitive overhead of having two interfaces so I came up with this. It does use a bit of reflection, but I couldn't find any other way to get at that object.
Long story short, it manually builds the setup expression against the internal type:
// Compile error, because Unit is internal
mock.Setup(x => x.Send<MyMessage, Unit>(It.IsAny<MyMessage>(), default));
But reflection and expression trees can still give it to us:
private static Type UnitType { get; } = typeof(IMessenger).Assembly
.GetType("Microsoft.Toolkit.Mvvm.Messaging.Internals.Unit");
public static ISetup<IMessenger, TMessage> SetupMessage<TMessage>(this Mock<IMessenger> messenger,
Expression<Func<TMessage, bool>>? validation = null)
where TMessage : class
{
MethodInfo sendMethod = typeof(IMessenger).GetMethod(nameof(IMessenger.Send))
.MakeGenericMethod(typeof(TMessage), UnitType);
ParameterExpression parameter = Expression.Parameter(typeof(IMessenger));
Expression<Func<TMessage>> message = validation switch
{
null => () => It.IsAny<TMessage>(),
not null => () => It.Is(validation),
};
MethodCallExpression methodCall = Expression.Call(
parameter,
sendMethod,
message.Body,
Expression.Default(UnitType));
Type funcType = Expression.GetFuncType(typeof(IMessenger), typeof(TMessage));
Expression lambda = Expression.Lambda(funcType, methodCall, parameter);
return messenger.Setup((Expression<Func<IMessenger, TMessage>>) lambda);
}
I read many question in this forum but nothing works.
public #interface MyAnnotation {
String value() default "";
Class[] exceptionList;
}
#MyAnnotation(value="hello", exceptionList={TimeOutException.class})
public void method() {}
#Aspect
public class MyAspect {
#Around("#annotation(MyAnnotation)")
public Object handle(ProceedingJoinPoint joinPoint, MyAnnotation myAnnotation) {
System.out.println(myAnnotation.exceptionList); // should print out TimeOutException
}
}
How can I get the value and the exceptionList of the #MyAnnotation while executing the advice?
I'm using Spring 4.0.6, AspectJ 1.7.4
The solution for this is making sure the advice method's parameter name match the parameter name in AspectJ expression. In my case, the advice method should look like this:
#Aspect
public class MyAspect {
#Around("#annotation(myAnnotation)")
public Object handle(ProceedingJoinPoint joinPoint, MyAnnotation myAnnotation) {
System.out.println(myAnnotation.exceptionList); // should print out TimeOutException
}
}
You are already almost there. Probably.
You are using the correct way to retrieve the annotation, so you have the values available.
Your problem - if I interpret the very minimalistic problem description(!) you only provide via the comment in your code snippet(!) correctly - is the (wrong) assumption that sticking an array of the type Class into System.out.println() will print out the names of the Classes it contains. It does not. Instead it prints information about the reference:
[Ljava.lang.Class;#15db9742
If you want the names of the Classes, you will have to iterate over the elements of that array and use .getName(), .getSimpleName() or one of the other name providing methods of Class.
Further information on how to print elements of an array is here:
What's the simplest way to print a Java array?
Granted, this whole answer could be entirely besides the point if the problem is that you are getting null values from the annotation fields. But since you have not provided an adequate problem description ("nothing works" is not a problem description!), we can only guess at what your problem is.
While creating classes using Generators, it's possible to discover all subclasses of a type. You can find this technique for example in the GWT Showcase source (see full code):
JClassType cwType = null;
try {
cwType = context.getTypeOracle().getType(ContentWidget.class.getName());
} catch (NotFoundException e) {
logger.log(TreeLogger.ERROR, "Cannot find ContentWidget class", e);
throw new UnableToCompleteException();
}
JClassType[] types = cwType.getSubtypes();
I would like to do something similar, but instead of extending a class (or implementing an interface)
public class SomeWidget extends ContentWidget { ... }
, could I also do this by annotating Widgets?
#MyAnnotation(...)
public class SomeWidget extends Widget { ... }
And then finding all Widgets that are annotated with #MyAnnotation? I couldn't find a method like JAnnotationType.getAnnotatedTypes(), but maybe I'm just blind?
Note: I was able to make it work with the Google Reflections library, using reflections.getTypesAnnotatedWith(SomeAnnotation.class), but I'd prefer using the GeneratorContext instead, especially because this works a lot better when reloading the app in DevMode.
Yes - easiest way is to iterate through all types, and check them for the annotation. You might have other rules too (is public, is non-abstract) that should also be done at that time.
for (JClassType type : oracle.getTypes()) {
MyAnnotation annotation = type.getAnnotation(MyAnnotation.class);
if (annotation != null && ...) {
// handle this type
}
}
The TypeOracle instance can be obtained from the GeneratorContext using context.getTypeOracle().
Note that this will only give you access to types on the source path. That is, only types currently available based on the modules being inherited and <source> tags in use.
i have a question.i have a method (Filter),i want to pass T dynamic.but it dosen`t accept.how can i do it?
public List<T> Filter<T>(string TypeOfCompare)
{
List<T> ReturnList2 = new List<T>();
return ReturnList2;
}
IList MakeListOfType(Type listType)
{
Type listType1 = typeof(List<>);
Type specificListType = listType.MakeGenericType(listType1);
return (IList)Activator.CreateInstance(specificListType);
}
Filter < ConstructGenericList(h) > ("s");
IList MakeListOfType(Type listType)
{
Type listType1 = typeof(List<>);
Type specificListType = listType.MakeGenericType(listType1);
return (IList)Activator.CreateInstance(specificListType);
}
It should be the other way round, you should call MakeGenericType on the generic type definition, not on the generic type argument. So the code becomes this:
IList MakeListOfType(Type elementType)
{
Type listType = typeof(List<>);
Type specificListType = listType.MakeGenericType(elementType);
return (IList)Activator.CreateInstance(specificListType);
}
(note that I changed the variables names to make the code clearer)
Generic parameters must have a type able to be determined at compile time (without resorting to something like functional type inference that some other languages have). So, you can't just stick a function between the angle brackets to get the type you want.
Edit:
Now that I know what you're trying to do, I would suggest a different approach entirely.
You mention that you are using Entity Framework, and you are trying to use one method to get a list of different types of objects. Those objects -- like Student and Teacher -- must have something in common, though, else you would not be trying to use the same method to retrieve a list of them. For example, you may just be wanting to display a name and have an ID to use as a key.
In that case, I would suggest defining an interface that has the properties common to Student, Teacher, etc. that you actually need, then returning a list of that interface type. Within the method, you would essentially be using a variant of the factory pattern.
So, you could define an interface like:
public interface INamedPerson
{
int ID { get; }
string FirstName { get; }
string LastName { get; }
}
Make your entities implement this interface. Auto-generated entities are (typically) partial classes, so in your own, new code files (not in the auto-generated code files themselves), you would do something like:
public partial class Student : INamedPerson
{
public int ID
{
get
{
return StudentId;
}
}
}
and
public partial class Teacher : INamedPerson
{
public int ID
{
get
{
return TeacherId;
}
}
}
Now, you may not even need to add the ID property if you already have it. However, if the identity property in each class is different, this adapter can be one way to implement the interface you need.
Then, for the method itself, an example would be:
public List<INamedPerson> MakeListOfType(Type type)
{
if (type == typeof(Student))
{
// Get your list of students. I'll just use a made-up
// method that returns List<Student>.
return GetStudentList().Select<Student, INamedPerson>(s => (INamedPerson)s)
.ToList<INamedPerson>();
}
if (type == typeof(Teacher))
{
return GetTeacherList().Select<Teacher, INamedPerson>(t => (INamedPerson)t)
.ToList<INamedPerson>();
}
throw new ArgumentException("Invalid type.");
}
Now, there are certainly ways to refine this pattern. If you have a lot of related classes, you may want to use some sort of dependency injection framework. Also, you may notice that there is a lot of duplication of code. You could instead pass a function (like GetStudentList or GetTeacherList) by doing something like
public List<INamedPerson> GetListFromFunction<T>(Func<IEnumerable<T>> theFunction) where T : INamedPerson
{
return theFunction().Select<T, INamedPerson>(t => (INamedPerson)t).ToList<INamedPerson>();
}
Of course, using this function requires, once again, the type passed in to be known at compile time. However, at some point, you're going to have to decide on a type, so maybe that is the appropriate time. Further, you can make your life a little simpler by leaving off the generic type at method call time; as long as you are passing in a function that takes no arguments and returns an IEnumerable of objects of the same type that implement INamedPerson, the compiler can figure out what to use for the generic type T.
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.