Compat - Totally makes compatibility layer for .NET platforms.

Package	NuGet
Compat

• TODO: Still under construction...

Totally makes compatibility layer for .NET platforms.

For examples:

// Undefined in net35:
if (string.IsNullOrWhitespace("ABC"))
{
}

// Use Compat and use StringEx instead:
if (StringEx.IsNullOrWhitespace("ABC"))
{
}

// Undefined in most .NET Frameworks without using Compat.
// (Zip operator simple overload)
var zipped = left.Zip(right);

// Undefined under net6.0 without using Compat.
// (WaitAsync method)
var zipped = this.CalculateAsync().WaitAsync(token);

// Undefined TFM complex condition without using Compat.
// (ValueTask and ValueTask<T> types)
public async ValueTask<int> CalculateAsync()
{
    // (Has ability of awaitable)
    await this.RunOtherCalculationAsync();
}

• .NET 7, 6, 5
• .NET Core 3.1, 3.0, 2.2, 2.1, 2.0
• .NET Standard 2.1, 2.0, 1.6, 1.3
• .NET Framework 4.8, 4.6.2, 4.6.1, 4.5.2, 4.5, 4.0, 3.5

Install Compat package.

The list is not completed minor status.

Lack some Task members in earlier third-party library:

• System.Threading.Tasks.TaskEx.FromException() is not defined in third-party library.
  • Use Task.Factory.FromException() instead.
  • Mostly useful From{...} type method. So defined Task.Factory.FromResult() in near place.
  • Mostly useful CompletedTask property. So defined Task.Factory.CompletedTask() method in near place.

When you want to build .NET Framework project in Linux and other non-Windows environment, that package supports ability for referencing of .NET Framework assemblies:

<ItemGroup>
  <PackageReference
    Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3"
    PrivateAssets="All" />
</ItemGroup>

We suggest using ILRepack.FullAuto.

Backport PRs are welcome. The following is our backporting policy:

• Basically, target under the System namespace of the BCL library.
• If a class, structure, or other type does not exist in the first place, define a new one.
• Use extended methods when porting instance methods.
• When porting instance properties or static members, define a type with Ex at the end and define members there.
  • This is to conform to existing conventions, such as TaskEx for Task.
• If you refer to a third-party library, there must be no alternative to this library or it must be well known.
  • Example: AsyncBridge package, which was a community-based pre-distribution in TPL.
  • Example: Microsoft.Bcl.Async package, which provides backward compatibility of Task with .NET Framework 4.0.
• When referencing third-party libraries, do not generate unnecessary references.
  • For example, net6.0 is nearly up-to-date, and references to libraries should not be included when using net6.0. To achieve this, define the PackageReference to be excluded by Condition.
• Add the new TFM if it is to fill an incompatibility with a TFM that is not currently included.
• Do not include non-backporting any extensions.
• Write some kind of unit test. Of course, a comprehensive and exhaustive test code would be perfect.

Apache-v2.

• 0.3.0:
  • Added Unsafe methods (partially).
  • Adjusted ValueTask related package version dependency.
• 0.2.0:
  • Added some LINQ operators.
  • Added Task.WaitAsync methods.
• 0.1.0:
  • Added ValueTask, ValueTuple and some minor members.
  • Adjust dependencies.
• 0.0.1:
  • Initial public release.