svrnty-mcp-client/tests/Svrnty.MCP.Client.Core.Tests/Infrastructure/McpClientTests.cs

using Moq;
using Svrnty.MCP.Client.Core.Abstractions;
using Svrnty.MCP.Client.Core.Exceptions;
using Svrnty.MCP.Client.Core.Models;
using Svrnty.MCP.Client.Infrastructure;
using Xunit;

namespace Svrnty.MCP.Client.Core.Tests.Infrastructure;

/// <summary>
/// Unit tests for McpClient following TDD approach.
/// Tests client initialization, server management, and tool operations.
/// </summary>
public class McpClientTests
{
    [Fact]
    public void Constructor_WithServerConfigs_CreatesClient()
    {
        // Arrange
        var configs = new List<McpServerConfig>
        {
            CreateTestConfig("server1"),
            CreateTestConfig("server2")
        };

        // Act
        var client = new McpClient(configs);

        // Assert
        Assert.NotNull(client);
    }

    [Fact]
    public async Task ConnectAllAsync_WithMultipleServers_ConnectsAll()
    {
        // Arrange
        var configs = new List<McpServerConfig>
        {
            CreateTestConfig("server1"),
            CreateTestConfig("server2")
        };
        var client = new McpClient(configs);

        // Act
        await client.ConnectAllAsync();

        // Assert
        var servers = await client.GetConnectedServersAsync();
        Assert.Equal(2, servers.Count());
    }

    [Fact]
    public async Task DisconnectAllAsync_AfterConnect_DisconnectsAll()
    {
        // Arrange
        var configs = new List<McpServerConfig> { CreateTestConfig("server1") };
        var client = new McpClient(configs);
        await client.ConnectAllAsync();

        // Act
        await client.DisconnectAllAsync();

        // Assert
        var servers = await client.GetConnectedServersAsync();
        Assert.Empty(servers);
    }

    [Fact]
    public async Task GetConnectedServersAsync_WithNoServers_ReturnsEmpty()
    {
        // Arrange
        var client = new McpClient(new List<McpServerConfig>());

        // Act
        var servers = await client.GetConnectedServersAsync();

        // Assert
        Assert.Empty(servers);
    }

    [Fact]
    public async Task ListToolsAsync_WithNonExistentServer_ThrowsServerNotFoundException()
    {
        // Arrange
        var client = new McpClient(new List<McpServerConfig>());

        // Act & Assert
        await Assert.ThrowsAsync<ServerNotFoundException>(
            async () => await client.ListToolsAsync("non-existent-server")
        );
    }

    [Fact]
    public async Task CallToolAsync_WithNonExistentServer_ThrowsServerNotFoundException()
    {
        // Arrange
        var client = new McpClient(new List<McpServerConfig>());

        // Act & Assert
        await Assert.ThrowsAsync<ServerNotFoundException>(
            async () => await client.CallToolAsync("non-existent-server", "test_tool")
        );
    }

    [Fact]
    public async Task PingAsync_WithNonExistentServer_ThrowsServerNotFoundException()
    {
        // Arrange
        var client = new McpClient(new List<McpServerConfig>());

        // Act & Assert
        await Assert.ThrowsAsync<ServerNotFoundException>(
            async () => await client.PingAsync("non-existent-server")
        );
    }

    [Fact]
    public async Task DisposeAsync_AfterConnect_DisposesCleanly()
    {
        // Arrange
        var configs = new List<McpServerConfig> { CreateTestConfig("server1") };
        var client = new McpClient(configs);
        await client.ConnectAllAsync();

        // Act
        await client.DisposeAsync();

        // Assert
        var servers = await client.GetConnectedServersAsync();
        Assert.Empty(servers);
    }

    [Fact]
    public async Task ListToolsAsync_WithConnectedServer_ReturnsTools()
    {
        // Arrange
        var configs = new List<McpServerConfig> { CreateTestConfig("server1") };
        var client = new McpClient(configs);
        await client.ConnectAllAsync();

        // Act
        var tools = await client.ListToolsAsync("server1");

        // Assert
        Assert.NotNull(tools);
    }

    [Fact]
    public async Task CallToolAsync_WithConnectedServer_ReturnsResult()
    {
        // Arrange
        var configs = new List<McpServerConfig> { CreateTestConfig("server1") };
        var client = new McpClient(configs);
        await client.ConnectAllAsync();

        // Act
        var result = await client.CallToolAsync("server1", "test_tool");

        // Assert
        Assert.NotNull(result);
    }

    private static McpServerConfig CreateTestConfig(string name)
    {
        return new McpServerConfig
        {
            Name = name,
            Transport = new StdioTransportConfig
            {
                Type = "Stdio",
                Command = "echo",
                Args = new[] { "test" }
            }
        };
    }
}