Rendezvous/tests/FinalFactory.Rendezvous.Tests/Contracts/OpenApiCompatibilityTests.cs

using System.Text.Json;

namespace FinalFactory.Rendezvous.Tests.Contracts;

public sealed class OpenApiCompatibilityTests
{
    private static readonly string[] ExpectedPaths =
    [
        "/health/live",
        "/health/ready",
        "/v1/join-attempts",
        "/v1/join-attempts/{attemptId}",
        "/v1/join-attempts/{attemptId}/outcome",
        "/v1/sessions",
        "/v1/sessions/{listingId}",
        "/v1/sessions/{listingId}/join-attempts",
        "/v1/sessions/{listingId}/renew",
    ];

    private static readonly string[] ExpectedListingProperties =
    [
        "buildVersion",
        "capacity",
        "contractVersion",
        "dedicatedFallback",
        "displayName",
        "environmentId",
        "gameId",
        "listingId",
        "metadata",
        "protocolVersion",
        "publisherTrustMode",
        "regionId",
        "visibility",
    ];

    [Fact]
    public void GeneratedOpenApiContainsTheFrozenV1Surface()
    {
        string path = Path.Combine(
            ContractTestFiles.Directory,
            "../../../../../docs/api/rendezvous-v1.json");
        using JsonDocument document = JsonDocument.Parse(File.ReadAllText(Path.GetFullPath(path)));
        JsonElement root = document.RootElement;

        Assert.Equal("3.1.1", root.GetProperty("openapi").GetString());
        string[] paths = root.GetProperty("paths")
            .EnumerateObject()
            .Select(static item => item.Name)
            .Order(StringComparer.Ordinal)
            .ToArray();
        Assert.Equal(ExpectedPaths, paths);

        JsonElement schemas = root.GetProperty("components").GetProperty("schemas");
        Assert.Equal("string", schemas.GetProperty("GameId").GetProperty("type").GetString());
        Assert.Equal("uuid", schemas.GetProperty("SessionListingId").GetProperty("format").GetString());

        string[] listingProperties = schemas.GetProperty("SessionListing")
            .GetProperty("properties")
            .EnumerateObject()
            .Select(static item => item.Name)
            .Order(StringComparer.Ordinal)
            .ToArray();
        Assert.Equal(ExpectedListingProperties, listingProperties);
        Assert.DoesNotContain(listingProperties, static property =>
            property.Contains("token", StringComparison.OrdinalIgnoreCase)
            || property.Contains("playerId", StringComparison.OrdinalIgnoreCase));
        JsonElement dedicatedFallback = schemas.GetProperty("SessionListing")
            .GetProperty("properties")
            .GetProperty("dedicatedFallback");
        JsonElement fallbackReference = Assert.Single(
            dedicatedFallback.GetProperty("oneOf").EnumerateArray(),
            static schema => schema.TryGetProperty("$ref", out _));
        Assert.Equal(
            "#/components/schemas/NetworkEndpoint",
            fallbackReference.GetProperty("$ref").GetString());

        JsonElement outcomeReportProperties = schemas.GetProperty("ReportConnectionOutcomeRequest")
            .GetProperty("properties");
        Assert.True(outcomeReportProperties.TryGetProperty("elapsedBucket", out _));
        Assert.True(outcomeReportProperties.TryGetProperty("elapsedMilliseconds", out _));
        Assert.True(outcomeReportProperties.TryGetProperty("diagnosticCode", out _));
        string[] outcomeNames = schemas.GetProperty("ConnectionOutcomeKind")
            .GetProperty("enum")
            .EnumerateArray()
            .Select(static value => value.GetString()!)
            .ToArray();
        Assert.Contains("timedOut", outcomeNames);
        Assert.Contains("staleHost", outcomeNames);
        Assert.Contains("transportFailed", outcomeNames);
        Assert.Contains("punchTimedOut", outcomeNames);
        Assert.Contains("directConnectTimedOut", outcomeNames);
        Assert.Contains("transportError", outcomeNames);

        JsonElement publisherBearer = root.GetProperty("components")
            .GetProperty("securitySchemes")
            .GetProperty("PublisherBearer");
        Assert.Equal("http", publisherBearer.GetProperty("type").GetString());
        Assert.Equal("bearer", publisherBearer.GetProperty("scheme").GetString());
        JsonElement attemptCapability = root.GetProperty("components")
            .GetProperty("securitySchemes")
            .GetProperty("JoinAttemptCapability");
        Assert.Equal("apiKey", attemptCapability.GetProperty("type").GetString());
        Assert.Equal(
            "X-Rendezvous-Client-Punch-Capability",
            attemptCapability.GetProperty("name").GetString());
        (string Path, string Method)[] publisherOperations =
        [
            ("/v1/sessions", "post"),
            ("/v1/sessions/{listingId}", "put"),
            ("/v1/sessions/{listingId}", "delete"),
            ("/v1/sessions/{listingId}/renew", "post"),
        ];
        foreach ((string operationPath, string method) in publisherOperations)
        {
            JsonElement security = root.GetProperty("paths")
                .GetProperty(operationPath)
                .GetProperty(method)
                .GetProperty("security");
            Assert.True(security[0].TryGetProperty("PublisherBearer", out _));
        }

        JsonElement cancelParameters = root.GetProperty("paths")
            .GetProperty("/v1/join-attempts/{attemptId}")
            .GetProperty("delete")
            .GetProperty("parameters");
        JsonElement cancelCapability = Assert.Single(cancelParameters.EnumerateArray(), static parameter =>
            parameter.GetProperty("in").GetString() == "header"
            && parameter.GetProperty("name").GetString()
                == "X-Rendezvous-Client-Punch-Capability");
        Assert.True(cancelCapability.GetProperty("required").GetBoolean());
        foreach ((string operationPath, string method) in new[]
                 {
                     ("/v1/join-attempts/{attemptId}", "delete"),
                     ("/v1/join-attempts/{attemptId}/outcome", "post"),
                 })
        {
            JsonElement security = root.GetProperty("paths")
                .GetProperty(operationPath)
                .GetProperty(method)
                .GetProperty("security");
            Assert.True(security[0].TryGetProperty("JoinAttemptCapability", out _));
        }
        JsonElement hostPollParameters = root.GetProperty("paths")
            .GetProperty("/v1/sessions/{listingId}/join-attempts")
            .GetProperty("get")
            .GetProperty("parameters");
        JsonElement leaseToken = Assert.Single(hostPollParameters.EnumerateArray(), static parameter =>
            parameter.GetProperty("in").GetString() == "header"
            && parameter.GetProperty("name").GetString() == "X-Rendezvous-Lease-Token");
        Assert.True(leaseToken.GetProperty("required").GetBoolean());
    }
}