refactor(ffi-interop): Add plugin driver and refactor mock server interop methods

Author: max-lancaster

samples/Grpc/GrpcGreeterClient.Tests/GrpcGreeterClientTest.cs

@@ -25,7 +25,7 @@ public async Task ReturnsMismatchWhenNoGrpcClientRequestMade()
             // arrange
             var host = "0.0.0.0";
             var pact = NativeInterop.NewPact("grpc-greeter-client", "grpc-greeter");
-            var interaction = NativeInterop.NewSyncMessageInteraction(pact, "a request to a plugin");
+            var interaction = PluginInterop.NewSyncMessageInteraction(pact, "a request to a plugin");
             NativeInterop.WithSpecification(pact, PactSpecification.V4);
             var content = $@"{{
                     ""pact:proto"":""{Path.Join(Directory.GetCurrentDirectory(), "..", "..", "..", "..", "GrpcGreeterClient", "Protos", "greet.proto").Replace("\\", "\\\\")}"",
@@ -38,10 +38,11 @@ public async Task ReturnsMismatchWhenNoGrpcClientRequestMade()
                         ""message"": ""matching(type, 'Hello foo')""
                     }}
                 }}";
-            PluginInterop.PluginAdd(pact, "protobuf", "0.4.0");
+
+            using var pluginDriver = pact.UsePlugin("protobuf", "0.4.0");
             PluginInterop.PluginInteractionContents(interaction, 0, "application/grpc", content);
 
-            using var driver = MockServer.CreateMockServer(pact, host, 0, "grpc", false);
+            using var driver = pact.CreateMockServer(host, 0, "grpc", false);
             var port = driver.Port;
             testOutputHelper.WriteLine("Port: " + port);
 
@@ -58,7 +59,6 @@ public async Task ReturnsMismatchWhenNoGrpcClientRequestMade()
             ErrorString.Should().Be("Did not receive any requests for path 'Greeter/SayHello'");
             ExpectedPath.Should().Be("Greeter/SayHello");
 
-            PluginInterop.PluginCleanup(pact);
             await Task.Delay(1);
         }
         [Fact]
@@ -67,7 +67,7 @@ public async Task WritesPactWhenGrpcClientRequestMade()
             // arrange
             var host = "0.0.0.0";
             var pact = NativeInterop.NewPact("grpc-greeter-client", "grpc-greeter");
-            var interaction = NativeInterop.NewSyncMessageInteraction(pact, "a request to a plugin");
+            var interaction = PluginInterop.NewSyncMessageInteraction(pact, "a request to a plugin");
             NativeInterop.WithSpecification(pact, PactSpecification.V4);
             var content = $@"{{
                     ""pact:proto"":""{Path.Join(Directory.GetCurrentDirectory(), "..", "..", "..", "..", "GrpcGreeterClient", "Protos", "greet.proto").Replace("\\", "\\\\")}"",
@@ -81,10 +81,10 @@ public async Task WritesPactWhenGrpcClientRequestMade()
                     }}
                 }}";
 
-            PluginInterop.PluginAdd(pact, "protobuf", "0.4.0");
+            using var pluginDriver = pact.UsePlugin("protobuf", "0.4.0");
             PluginInterop.PluginInteractionContents(interaction, 0, "application/grpc", content);
 
-            using var driver = MockServer.CreateMockServer(pact, host, 0, "grpc", false);
+            using var driver = pact.CreateMockServer(host, 0, "grpc", false);
             var port = driver.Port;
             testOutputHelper.WriteLine("Port: " + port);
 
@@ -105,7 +105,6 @@ public async Task WritesPactWhenGrpcClientRequestMade()
             MismatchesString.Should().Be("[]");
 
             PactFileWriter.WritePactFileForPort(port, "../../../../pacts");
-            PluginInterop.PluginCleanup(pact);
         }
 
     }

src/PactNet.Abstractions/Drivers/IPluginDriver.cs

@@ -0,0 +1,7 @@
+using System;
+
+namespace PactNet.Drivers;
+
+public interface IPluginDriver : IDisposable
+{
+}

src/PactNet.Interop/NativeInterop.cs

@@ -55,9 +55,6 @@ public static class NativeInterop
 
         #region Messaging Interop Support
 
-        [DllImport(DllName, EntryPoint = "pactffi_new_sync_message_interaction")]
-        public static extern uint NewSyncMessageInteraction(PactHandle pact, string description);
-
         [DllImport(DllName, EntryPoint = "pactffi_with_message_pact_metadata")]
         public static extern void WithMessagePactMetadata(PactHandle pact, string @namespace, string name, string value);
 

src/PactNet.Interop/MockServer.cs renamed to src/PactNet.Interop/PactHandleExtensions.cs

@@ -3,7 +3,7 @@
 
 namespace PactNet.Interop;
 
-public static class MockServer
+public static class PactHandleExtensions
 {
     /// <summary>
     /// Create the mock server for the current pact
@@ -13,9 +13,9 @@ public static class MockServer
     /// <param name="port">Port for the mock server, or null to allocate one automatically</param>
     /// <param name="transport">Transport type for the mock server</param>
     /// <param name="tls">Enable TLS</param>
-    /// <returns>Mock server port</returns>
+    /// <returns>IMockServerDriver</returns>
     /// <exception cref="InvalidOperationException">Failed to start mock server</exception>
-    public static IMockServerDriver CreateMockServer(PactHandle pact, string host, int? port, string transport, bool tls)
+    public static IMockServerDriver CreateMockServer(this PactHandle pact, string host, int? port, string transport, bool tls)
     {
         int result = MockServerInterop.CreateMockServerForTransport(pact, host, (ushort)port.GetValueOrDefault(0), transport, null);
 
@@ -34,4 +34,23 @@ public static IMockServerDriver CreateMockServer(PactHandle pact, string host, i
             _ => new InvalidOperationException($"Unknown mock server error: {result}")
         };
     }
+
+
+    public static IPluginDriver UsePlugin(this PactHandle pact, string plugInName, string pluginVersion)
+    {
+        uint result = PluginInterop.PluginAdd(pact, plugInName, pluginVersion);
+
+        if (result == 0)
+        {
+            return new PluginDriver(pact);
+        }
+
+        throw result switch
+        {
+            1 => new InvalidOperationException("The pact reference library panicked."),
+            2 => new InvalidOperationException("Failed to load the plugin."),
+            3 => new InvalidOperationException("Pact Handle is not valid."),
+            _ => new InvalidOperationException($"Unknown mock server error: {result}")
+        };
+    }
 }

src/PactNet.Interop/PluginDriver.cs

@@ -0,0 +1,32 @@
+using System;
+using PactNet.Drivers;
+
+namespace PactNet.Interop;
+
+internal class PluginDriver(PactHandle pact) : IPluginDriver
+{
+    /// <summary>
+    /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+    /// </summary>
+    public void Dispose()
+    {
+        this.ReleaseUnmanagedResources();
+        GC.SuppressFinalize(this);
+    }
+
+    /// <summary>
+    /// Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
+    /// </summary>
+    ~PluginDriver()
+    {
+        this.ReleaseUnmanagedResources();
+    }
+
+    /// <summary>
+    /// Release unmanaged resources
+    /// </summary>
+    private void ReleaseUnmanagedResources()
+    {
+        PluginInterop.PluginCleanup(pact);
+    }
+}

src/PactNet.Interop/PluginInterop.cs

@@ -6,11 +6,14 @@ public class PluginInterop
 {
     private const string DllName = "pact_ffi";
 
+    [DllImport(DllName, EntryPoint = "pactffi_new_sync_message_interaction")]
+    public static extern InteractionHandle NewSyncMessageInteraction(PactHandle pact, string description);
+
     [DllImport(DllName, EntryPoint = "pactffi_using_plugin")]
     public static extern uint PluginAdd(PactHandle pact, string name, string version);
 
     [DllImport(DllName, EntryPoint = "pactffi_interaction_contents")]
-    public static extern uint PluginInteractionContents(uint interaction, InteractionPart part, string contentType, string body);
+    public static extern uint PluginInteractionContents(InteractionHandle interaction, InteractionPart part, string contentType, string body);
 
     [DllImport(DllName, EntryPoint = "pactffi_cleanup_plugins")]
     public static extern void PluginCleanup(PactHandle pact);

src/PactNet/Drivers/HttpPactDriver.cs

@@ -38,7 +38,7 @@ public IHttpInteractionDriver NewHttpInteraction(string description)
         /// <param name="tls">Enable TLS</param>
         /// <returns>Mock server port</returns>
         /// <exception cref="InvalidOperationException">Failed to start mock server</exception>
-        public IMockServerDriver CreateMockServer(string host, int? port, bool tls) => MockServer.CreateMockServer(this.pact, host, port, "http", tls);
+        public IMockServerDriver CreateMockServer(string host, int? port, bool tls) => this.pact.CreateMockServer(host, port, "http", tls);
 
         public void WritePactFile(string directory) => PactFileWriter.WritePactFile(this.pact,  directory);
     }