git.stella-ops.org/tests/StellaOps.Router.Gateway.Tests/RateLimitRouteMatcherTests.cs

using FluentAssertions;
using StellaOps.Router.Gateway.RateLimit;
using Xunit;

namespace StellaOps.Router.Gateway.Tests;

public sealed class RateLimitRouteMatcherTests
{
    [Fact]
    public void TryMatch_ExactBeatsPrefixAndRegex()
    {
        var microservice = new MicroserviceLimitsConfig
        {
            Routes = new Dictionary<string, RouteLimitsConfig>(StringComparer.OrdinalIgnoreCase)
            {
                ["exact"] = new RouteLimitsConfig
                {
                    Pattern = "/api/scans",
                    MatchType = RouteMatchType.Exact,
                    Rules = [new RateLimitRule { PerSeconds = 10, MaxRequests = 1 }]
                },
                ["prefix"] = new RouteLimitsConfig
                {
                    Pattern = "/api/scans/*",
                    MatchType = RouteMatchType.Prefix,
                    Rules = [new RateLimitRule { PerSeconds = 10, MaxRequests = 1 }]
                },
                ["regex"] = new RouteLimitsConfig
                {
                    Pattern = "^/api/scans/[a-f0-9-]+$",
                    MatchType = RouteMatchType.Regex,
                    Rules = [new RateLimitRule { PerSeconds = 10, MaxRequests = 1 }]
                },
            }
        };

        microservice.Validate("microservice");

        var matcher = new RateLimitRouteMatcher();
        var match = matcher.TryMatch(microservice, "/api/scans");

        match.Should().NotBeNull();
        match!.Value.Name.Should().Be("exact");
    }

    [Fact]
    public void TryMatch_LongestPrefixWins()
    {
        var microservice = new MicroserviceLimitsConfig
        {
            Routes = new Dictionary<string, RouteLimitsConfig>(StringComparer.OrdinalIgnoreCase)
            {
                ["short"] = new RouteLimitsConfig
                {
                    Pattern = "/api/*",
                    MatchType = RouteMatchType.Prefix,
                    Rules = [new RateLimitRule { PerSeconds = 10, MaxRequests = 1 }]
                },
                ["long"] = new RouteLimitsConfig
                {
                    Pattern = "/api/scans/*",
                    MatchType = RouteMatchType.Prefix,
                    Rules = [new RateLimitRule { PerSeconds = 10, MaxRequests = 1 }]
                },
            }
        };

        microservice.Validate("microservice");

        var matcher = new RateLimitRouteMatcher();
        var match = matcher.TryMatch(microservice, "/api/scans/123");

        match.Should().NotBeNull();
        match!.Value.Name.Should().Be("long");
    }
}