HTTP Head support

src/Convey.WebApi.CQRS/src/Convey.WebApi.CQRS/Builders/DispatcherEndpointsBuilder.cs

@@ -122,6 +122,42 @@ public IDispatcherEndpointsBuilder Delete<T>(string path, Func<T, HttpContext, T
         return this;
     }
 
+    public IDispatcherEndpointsBuilder Head(string path, Func<HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies)
+    {
+        _builder.Head(path, context, endpoint, auth, roles, policies);
+
+        return this;
+    }
+
+    public IDispatcherEndpointsBuilder Head<T>(string path,
+        Func<T, HttpContext, Task> beforeDispatch = null,
+        Func<T, bool, HttpContext, Task> afterDispatch = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies) where T : class, IQuery<bool>
+    {
+        _builder.Head<T>(path, async (query, ctx) =>
+        {
+            if (beforeDispatch is not null)
+            {
+                await beforeDispatch(query, ctx);
+            }
+
+            var dispatcher = ctx.RequestServices.GetRequiredService<IQueryDispatcher>();
+            var result = await dispatcher.QueryAsync<T, bool>(query);
+            if (afterDispatch is null)
+            {
+                ctx.Response.StatusCode = result ? 200 : 404;
+                return;
+            }
+
+            await afterDispatch(query, result, ctx);
+        }, endpoint, auth, roles, policies);
+
+        return this;
+    }
+
     private static async Task BuildCommandContext<T>(T command, HttpContext context,
         Func<T, HttpContext, Task> beforeDispatch = null,
         Func<T, HttpContext, Task> afterDispatch = null) where T : class, ICommand

src/Convey.WebApi.CQRS/src/Convey.WebApi.CQRS/IDispatcherEndpointsBuilder.cs

@@ -48,4 +48,14 @@ IDispatcherEndpointsBuilder Delete<T>(string path, Func<T, HttpContext, Task> be
         bool auth = false, string roles = null,
         params string[] policies)
         where T : class, ICommand;
+
+    IDispatcherEndpointsBuilder Head(string path, Func<HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies);
+
+    IDispatcherEndpointsBuilder Head<T>(string path,
+        Func<T, HttpContext, Task> beforeDispatch = null,
+        Func<T, bool, HttpContext, Task> afterDispatch = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies) where T : class, IQuery<bool>;
 }

src/Convey.WebApi/src/Convey.WebApi/EndpointsBuilder.cs

@@ -134,6 +134,31 @@ public IEndpointsBuilder Delete<T>(string path, Func<T, HttpContext, Task> conte
         return this;
     }
 
+    public IEndpointsBuilder Head(string path, Func<HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies)
+    {
+        var builder = _routeBuilder.MapMethods(path, new[] { "HEAD" }, ctx => context?.Invoke(ctx) ?? Task.CompletedTask);
+        endpoint?.Invoke(builder);
+        ApplyAuthRolesAndPolicies(builder, auth, roles, policies);
+        AddEndpointDefinition(HttpMethods.Head, path);
+
+        return this;
+    }
+
+    public IEndpointsBuilder Head<T>(string path, Func<T, HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies)
+        where T : class
+    {
+        var builder = _routeBuilder.MapMethods(path, new[] { "HEAD" }, ctx => BuildQueryContext(ctx, context));
+        endpoint?.Invoke(builder);
+        ApplyAuthRolesAndPolicies(builder, auth, roles, policies);
+        AddEndpointDefinition<T>(HttpMethods.Head, path);
+
+        return this;
+    }
+
     private static void ApplyAuthRolesAndPolicies(IEndpointConventionBuilder builder, bool auth, string roles,
         params string[] policies)
     {

src/Convey.WebApi/src/Convey.WebApi/IEndpointsBuilder.cs

@@ -47,4 +47,13 @@ IEndpointsBuilder Delete<T>(string path, Func<T, HttpContext, Task> context = nu
         Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
         params string[] policies)
         where T : class;
+
+    IEndpointsBuilder Head(string path, Func<HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies);
+
+    IEndpointsBuilder Head<T>(string path, Func<T, HttpContext, Task> context = null,
+        Action<IEndpointConventionBuilder> endpoint = null, bool auth = false, string roles = null,
+        params string[] policies)
+        where T : class;
 }