Svrooij.PowerShell.DependencyInjection

A library that allows you to use dependency injection in binary PowerShell modules.

• Dependency injection (based on Microsoft.Extensions.DependencyInjection)
• Using ILogger throughout your PowerShell Module.
• Run any asynchronous code in your commandlets.

I choose to only support a Task, I guess that all code that you're executing using this package will by async anyway.

Create a new PowerShell module

# Install the correct template (only once)
dotnet new install Microsoft.PowerShell.Standard.Module.Template

# Create a new directory and enter it
mkdir MyNewModule
cd MyNewModule

# Create a new PowerShell module
dotnet new psmodule

Add Package

Add the pacakge dotnet add package Svrooij.PowerShell.DependencyInjection

Edit project file

Add the CopyLocalLockFileAssemblies to your project file, this will make sure that the dependencies are copied to the output folder.

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <AssemblyName>Svrooij.PowerShell.DependencyInjection.SamplePs5</AssemblyName>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
  </PropertyGroup>

And change the version of PowerShellStandard.Library to 5.1.1.

  <ItemGroup>
    <PackageReference Include="PowerShellStandard.Library" Version="5.1.1" />
    <PackageReference Include="Svrooij.PowerShell.DependencyInjection" Version="1.0.1" />
  </ItemGroup>

Create a Startup class

using Microsoft.Extensions.DependencyInjection;
using Svrooij.PowerShell.DependencyInjection;

public class Startup : PsStartup
    {
        // You need to override this method.
        public override void ConfigureServices(IServiceCollection services)
        {
            services.AddTransient<ITestService, TestService>();
        }
    }

Create a CmdLet

1. Instead of inheriting from PsCmdLet, you need to inherit DependencyCmdlet<YourStartupClass>.
2. And then you put the [ServiceDependency] attribute above every private (or internal), field or property you want loaded from dependency injection.
3. Override the Task ProcessRecordAsync(CancellationToken cancellationToken) method and call all the async stuff you want.

    [Cmdlet(VerbsDiagnostic.Test, "SampleCmdlet")]
    [OutputType(typeof(FavoriteStuff))]
    public class TestSampleCmdletCommand : DependencyCmdlet<YourStartupClass>
    {
        [Parameter(
            Mandatory = true,
            Position = 0,
            ValueFromPipeline = true,
            ValueFromPipelineByPropertyName = true)]
        public int FavoriteNumber { get; set; }

        [Parameter(
            Position = 1,
            ValueFromPipelineByPropertyName = true)]
        [ValidateSet("Cat", "Dog", "Horse")]
        public string FavoritePet { get; set; } = "Dog";

        // Give your dependencies the ServiceDependency attribute
        [ServiceDependency]
        private ITestService TestService { get; set; }

        // Logging using Microsoft.Extensions.Logging is supported (and configured automatically)
        // You can alse use the regular WriteVerbose(), WriteDebug(), WriteInformation(), WriteWarning() and WriteError() methods
        [ServiceDependency]
        private ILogger<TestSampleCmdletCommand> _logger;

        // This method will be called automatically by DependencyCmdlet which is called by ProcessRecord()
        public override async Task ProcessRecordAsync(CancellationToken cancellationToken)
        {
            _logger.LogInformation("Starting ProcessRecordAsync()");

            await TestService.DoSomethingAsync(cancellationToken);

            WriteObject(new FavoriteStuff
            {
                FavoriteNumber = this.FavoriteNumber,
                FavoritePet = this.FavoritePet
            });
        }
    }