w4c-workflows-api/w4c-workflows-api.Tests/EgressTestDoubles.cs

using System.Net;
using System.Net.Sockets;
using w4c_workflows.Services.Security;
using w4c_workflows.Services.Nodes;

namespace w4c_workflows.Tests;

/// <summary>
/// Deterministic <see cref="IHostAddressResolver"/> for egress tests: returns a
/// fixed address set per host and records every query, so tests never touch DNS.
/// </summary>
internal sealed class StubHostAddressResolver : IHostAddressResolver
{
    private readonly Func<string, IReadOnlyList<IPAddress>> _resolve;

    public StubHostAddressResolver(Func<string, IReadOnlyList<IPAddress>> resolve) => _resolve = resolve;

    public List<string> Queries { get; } = new();

    public Task<IReadOnlyList<IPAddress>> ResolveAsync(string host, CancellationToken ct)
    {
        Queries.Add(host);
        return Task.FromResult(_resolve(host));
    }

    public static StubHostAddressResolver Returning(params string[] addresses)
        => new(_ => addresses.Select(IPAddress.Parse).ToArray());

    public static StubHostAddressResolver Failing()
        => new(_ => throw new SocketException((int)SocketError.HostNotFound));
}

internal static class EgressTestData
{
    /// <summary>A routable public address used as the default stub answer.</summary>
    public const string PublicAddress = "93.184.216.34";

    public static EgressPolicy Policy(Action<EgressPolicyOptions>? configure = null)
    {
        var options = new EgressPolicyOptions();
        configure?.Invoke(options);
        return new EgressPolicy(options);
    }

    public static EgressGuard Guard(
        EgressPolicy? policy = null,
        IHostAddressResolver? resolver = null)
        => new(policy ?? Policy(), resolver ?? StubHostAddressResolver.Returning(PublicAddress));

    public static NodeRequestBudget Quota(Action<NodeQuotaOptions>? configure = null)
    {
        var options = new NodeQuotaOptions();
        configure?.Invoke(options);
        return new NodeRequestBudget(options);
    }

    public static NodePermissionPolicy Permissions(Action<NodePermissionOptions>? configure = null)
    {
        var options = new NodePermissionOptions();
        configure?.Invoke(options);
        return new NodePermissionPolicy(options);
    }

    public static IReadOnlyList<IPAddress> Ips(params string[] addresses)
        => addresses.Select(IPAddress.Parse).ToArray();
}