Watch2–part 6- options

The Watch2 package passes all the command line arguments to the dotnet watch. So how can it have its own settings? Simple: by reading a watch.json file that is in the same folder where it is executing.

1. Testing
I was considering how to perform the testing, and there were two options:

Microsoft File Providers: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/file-providers?view=aspnetcore-8.0

TestableIO: https://github.com/TestableIO/System.IO.Abstractions

I thought that the second option (TestableIO) would be easier to use and more flexible. However, I do not need to test the creation of the file, but rather the content of the file. Therefore, I will use the first option (Microsoft File Providers).

2. Maintain JSON in Sync with C#
I need a solution to transform JSON to C# on the fly (i.e., at compile time). For this, a Roslyn Code Generator can be used. The rscgutils NuGet package will be helpful for this purpose.

Here is the relevant configuration in the project file:

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<ItemGroup>
    <PackageReference Include="Microsoft.Extensions.FileProviders.Abstractions" Version="8.0.0" />
    <PackageReference Include="rscgutils" Version="2024.2000.2000" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
</ItemGroup>
 
<ItemGroup>
    <ProjectReference Include="..\Watch2_Interfaces\Watch2_Interfaces.csproj" />
</ItemGroup>
<ItemGroup>
    <AdditionalFiles Include="options.gen.json" />
</ItemGroup>

Code in Program.cs
The code in Program.cs will utilize the above configurations and packages. Here is an example of how it might look:

This example demonstrates how to read the watch.json file using the Microsoft File Providers package. The rscgutils package will handle the transformation of JSON to C# at compile time, ensuring that the JSON configuration is always in sync with the C# code.

So the code in program.cs will be:

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//test
//args = ["run --no-hot-reload"];
//string folder = @"D:\gth\RSCG_Examples\v2\Generator";
 
//uncomment this line for production
string folder = Environment.CurrentDirectory;
 
var serviceCollection = new ServiceCollection();
ConfigureServices(serviceCollection, folder);
 
var serviceProvider = serviceCollection.BuildServiceProvider();
 
var console = serviceProvider.GetRequiredService<IConsoleWrapper>();
var processManager = serviceProvider.GetRequiredService<ProcessManager>();
var startInfo = serviceProvider.GetRequiredService<IProcessStartInfo>();
 
var fileOptions = serviceProvider.GetRequiredService<IOptionsReader>();
if(!fileOptions.ExistsFile())
{
    var file = Path.Combine(folder, "watch2.json");
    File.WriteAllText(file, MyAdditionalFiles.options_gen_json);   
}
 
await processManager.StartProcessAsync(args, console, startInfo);
 
 
 
void ConfigureServices(IServiceCollection services,string folder)
{
    services.AddSingleton<IFileProvider>(new PhysicalFileProvider(folder));
    services.AddSingleton<IOptionsReader, OptionsReader>();
    services.AddSingleton<Ioptions_gen_json>(it =>
    {
        var optionsReader = it.GetRequiredService<IOptionsReader>();
        return optionsReader.GetOptions() ?? options_gen_json.Empty;
    });
    services.AddSingleton<IConsoleWrapper, ConsoleWrapper>();
    services.AddSingleton<ProcessManager, ProcessManager>();
    services.AddSingleton<IProcessStartInfo>(provider => new ProcessStartInfoWrapper
    {
    FileName = "dotnet",
    Arguments = "watch " + string.Join(' ', args),
    WorkingDirectory = folder,
    RedirectStandardOutput = true,
    RedirectStandardInput = true,
    RedirectStandardError = true,
    UseShellExecute = false,
    CreateNoWindow = true
    });
 
    services.AddLogging(loggingBuilder =>
    {
        loggingBuilder.ClearProviders();
        loggingBuilder.SetMinimumLevel(LogLevel.Trace);
        loggingBuilder.AddNLog("nlog.config");
    });
    services.AddSingleton<ILogger<ProcessManager>, Logger<ProcessManager>>();
    services.AddSingleton<Func<IProcessStartInfo, IProcessWrapper>>(it => new ProcessWrapper(it));
}