Poser 2.1.0
dotnet add package Poser --version 2.1.0
NuGet\Install-Package Poser -Version 2.1.0
<PackageReference Include="Poser" Version="2.1.0" />
paket add Poser --version 2.1.0
#r "nuget: Poser, 2.1.0"
// Install Poser as a Cake Addin #addin nuget:?package=Poser&version=2.1.0 // Install Poser as a Cake Tool #tool nuget:?package=Poser&version=2.1.0
Poser
Poser allows you to replace any .NET method (including static and non-virtual) with a delegate. It is similar to Microsoft Fakes but unlike it Poser is implemented entirely in managed code (Reflection Emit API). Everything occurs at runtime and in-memory, no unmanaged Profiling APIs and no file system pollution with re-written assemblies.
Poser is cross platform and runs anywhere .NET is supported. It targets .NET Standard 2.0 so it can be used across .NET platforms including .NET Framework, .NET Core, Mono and Xamarin. See version compatibility table here.
Installation
Available on NuGet
Visual Studio:
PM> Install-Package Poser
.NET Core CLI:
dotnet add package Poser
Usage
Poser gives you the ability to create shims by way of the Shim
class. Shims are basically objects that let you specify the method you want to replace as well as the replacement delegate. Delegate signatures (arguments and return type) must match that of the methods they replace. The Is
class is used to create instances of a type and all code you want to apply your shims to is isolated using the PoseContext
class.
Shim static method
using Pose;
Shim consoleShim = Shim.Replace(() => Console.WriteLine(Is.A<string>())).With(
delegate (string s) { Console.WriteLine("Hijacked: {0}", s); });
Shim static property getter
using Pose;
Shim dateTimeShim = Shim.Replace(() => DateTime.Now).With(() => new DateTime(2004, 4, 4));
Shim static property setter
using Pose;
Shim setterShim = Shim.Replace(() => Console.Title, true).With((string title) => { Console.Title = "My Title"; });
Shim instance property getter
using Pose;
class MyClass
{
public int MyProperty { get; set; }
public void DoSomething() => Console.WriteLine("doing someting");
}
Shim classPropShim = Shim.Replace(() => Is.A<MyClass>().MyProperty).With((MyClass @this) => 100);
Shim instance property setter
using Pose;
Shim classPropShim = Shim.Replace(() => Is.A<MyClass>().MyProperty, true).With((MyClass @this, int prop) => { @this.MyProperty = prop * 10; });
Shim constructor
using Pose;
Shim ctorShim = Shim.Replace(() => new MyClass()).With(() => new MyClass() { MyProperty = 10 });
Shim instance method of a Reference Type
using Pose;
Shim classShim = Shim.Replace(() => Is.A<MyClass>().DoSomething()).With(
delegate (MyClass @this) { Console.WriteLine("doing someting else"); });
Note: The first argument to an instance method replacement delegate is always the instance of the class
Shim method of specific instance of a Reference Type
using Pose;
MyClass myClass = new MyClass();
Shim myClassShim = Shim.Replace(() => myClass.DoSomething()).With(
delegate (MyClass @this) { Console.WriteLine("doing someting else with myClass"); });
Shim instance method of a Value Type
using Pose;
Shim structShim = Shim.Replace(() => Is.A<MyStruct>().DoSomething()).With(
delegate (ref MyStruct @this) { Console.WriteLine("doing someting else"); });
Note: You cannot shim methods on specific instances of Value Types
Shim operators
var operatorShim = Shim.Replace(() => Is.A<TimeSpan>() + Is.A<TimeSpan>()).With(
delegate(TimeSpan l, TimeSpan r) { return TimeSpan.Zero; });
Isolating your code
// This block executes immediately
PoseContext.Isolate(() =>
{
// All code that executes within this block
// is isolated and shimmed methods are replaced
// Outputs "Hijacked: Hello World!"
Console.WriteLine("Hello World!");
// Outputs "4/4/04 12:00:00 AM"
Console.WriteLine(DateTime.Now);
// Outputs "doing someting else"
new MyClass().DoSomething();
// Outputs "doing someting else with myClass"
myClass.DoSomething();
// Outputs '00:00:00'
Console.WriteLine(TimeSpan.FromDays(1) + TimeSpan.FromSeconds(2));
}, consoleShim, dateTimeShim, classPropShim, classShim, myClassShim, structShim, operatorShim);
Shimming operators
Operator shimming requires that the class/struct overloads the operator in question.
Poser supports shimming operators of the following kind:
- Arithmetic
+x
-x
!x
~x
x + y
x - y
x / y
x % y
x & y
x | y
x ^ y
x << y
x >> y
- Equality
x == y
x != y
- Comparison
x < y
x > y
x <= y
x >= y
In addition to this, both implicit and explicit conversion operators are supported.
Unsupported operators
Shimming of the following operators is not supported:
true
andfalse
because I cannot find a good way to express the operation in an expression tree.x >>> y
because expression trees cannot contain this operator. This is a limitation on the part of the compiler.++
and--
because these cannot be expressed in an expression tree.
Caveats & Limitations
- Breakpoints - At this time any breakpoints set anywhere in the isolated code and its execution path will not be hit. However, breakpoints set within a shim replacement delegate are hit.
- Exceptions - At this time all unhandled exceptions thrown in isolated code and its execution path are always wrapped in
System.Reflection.TargetInvocationException
.
Roadmap
- Performance Improvements - Poser can be used outside the context of unit tests. Better performance would make it suitable for use in production code, possibly to override legacy functionality.
- Exceptions Stack Trace - Currently when exceptions are thrown in your own code under isolation, the supplied exception stack trace is quite confusing. Providing an undiluted exception stack trace is needed.
Issues & Contributions
If you find a bug or have a feature request, please report them at this repository's issues section. Contributions are highly welcome, however, except for very small changes kindly file an issue and let's have a discussion before you open a pull request.
License
This project is licensed under the MIT license. See the LICENSE file for more info.
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net5.0 is compatible. net5.0-windows was computed. net6.0 was computed. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 is compatible. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 is compatible. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. |
.NET Core | netcoreapp2.0 is compatible. netcoreapp2.1 was computed. netcoreapp2.2 was computed. netcoreapp3.0 is compatible. netcoreapp3.1 was computed. |
.NET Standard | netstandard2.0 is compatible. netstandard2.1 was computed. |
.NET Framework | net461 was computed. net462 was computed. net463 was computed. net47 was computed. net471 was computed. net472 was computed. net48 is compatible. net481 was computed. |
MonoAndroid | monoandroid was computed. |
MonoMac | monomac was computed. |
MonoTouch | monotouch was computed. |
Tizen | tizen40 was computed. tizen60 was computed. |
Xamarin.iOS | xamarinios was computed. |
Xamarin.Mac | xamarinmac was computed. |
Xamarin.TVOS | xamarintvos was computed. |
Xamarin.WatchOS | xamarinwatchos was computed. |
-
- Mono.Reflection.Core (>= 1.1.1)
- System.Reflection.Emit.Lightweight (>= 4.3.0)
- System.Runtime.CompilerServices.Unsafe (>= 5.0.0)
NuGet packages
This package is not used by any NuGet packages.
GitHub repositories
This package is not used by any popular GitHub repositories.
Version | Downloads | Last updated |
---|---|---|
2.1.0 | 3,439 | 6/6/2024 |
2.1.0-alpha0001 | 140 | 1/28/2024 |
2.0.1 | 2,489 | 2/2/2024 |
2.0.0 | 382 | 1/24/2024 |
Add support for shimming operators