Sub-operations

What are they?

Sub-operations track and organise blocks of execution where it doesn't make sense to refactor into a module. This is useful when iterating through data in a loop.

For instance, you have 10 .NET projects to package into NuGet packages.

By declaring each package operation as a sub-operation, you can track failures and see each duration in the console progress display.

A sub-operation takes a name and a token-aware body to execute.

If a sub-operation fails, its original exception propagates while its name remains visible in progress output.

In the example below, the .csproj filename identifies each sub-operation.

Example

public class PackProjectsModule : Module<CommandResult[]>
{
    protected override async Task<CommandResult[]> ExecuteAsync(IModuleContext context, CancellationToken cancellationToken)
    {
        var packageVersion = await context.GetModule<NugetVersionGeneratorModule>();

        var repositoryInfo = await context.Tools.Git.Information.GetInfoAsync(cancellationToken)
            ?? throw new InvalidOperationException("Git repository information is unavailable.");
        var projects = repositoryInfo.Root
            .GetFiles(x =>
                x.Extension == ".csproj" && !x.Name.Contains("test", StringComparison.InvariantCultureIgnoreCase))
            .ToList();

        return await PackProjects(context, projects, packageVersion.Value, cancellationToken).ToArrayAsync(cancellationToken: cancellationToken);
    }

    private async IAsyncEnumerable<CommandResult> PackProjects(IModuleContext context, List<FilePath> projects, string packageVersion, [EnumeratorCancellation] CancellationToken cancellationToken)
    {
        foreach (var project in projects)
        {
            yield return await context.RunSubModuleAsync(project.Name, token => context.Tools.DotNet.PackAsync(new DotNetPackOptions
            {
                TargetPath = project,
                Configuration = Configuration.Release,
                Properties = new List<string>
                {
                    $"PackageVersion={packageVersion}",
                    $"Version={packageVersion}",
                },
            }, token), cancellationToken);
        }
    }
}