From 02f7615ab06592ed0d2f0312e79473d3e8722831 Mon Sep 17 00:00:00 2001
From: Monica S <FiniteReality@users.noreply.github.com>
Date: Sat, 12 Jun 2021 12:19:43 +0100
Subject: [PATCH] Allow commands with no parameters to compile (#20)

Use `Array.Empty<T>()` instead of `new[] { }` or `new IParameter[] { }` when no parameters are specified
---
 .../Console/TestCommands/HelloWorldCommand.cs |  8 +++++++
 ...butedModelSourceGenerator.CommandSource.cs | 24 ++++++++++++-------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/samples/Console/TestCommands/HelloWorldCommand.cs b/samples/Console/TestCommands/HelloWorldCommand.cs
index e5cfa8f..9512261 100644
--- a/samples/Console/TestCommands/HelloWorldCommand.cs
+++ b/samples/Console/TestCommands/HelloWorldCommand.cs
@@ -42,5 +42,13 @@ public ValueTask<ICommandResult> HelloWorldCommand(
 
             return new ValueTask<ICommandResult>(new NoContentCommandResult());
         }
+
+        [Command("code")]
+        public ValueTask<ICommandResult> HelloCodeCommand()
+        {
+            _logger.LogInformation("Hello code from HelloModule!");
+
+            return new ValueTask<ICommandResult>(new NoContentCommandResult());
+        }
     }
 }
diff --git a/tools/SourceGenerators/Models/AttributedModel/AttributedModelSourceGenerator.CommandSource.cs b/tools/SourceGenerators/Models/AttributedModel/AttributedModelSourceGenerator.CommandSource.cs
index b6d94a5..dd3a37c 100644
--- a/tools/SourceGenerators/Models/AttributedModel/AttributedModelSourceGenerator.CommandSource.cs
+++ b/tools/SourceGenerators/Models/AttributedModel/AttributedModelSourceGenerator.CommandSource.cs
@@ -80,6 +80,13 @@ var parameterNamespaces
                     .Select(
                         x => $"new CommandFactory__{@class.Name}__{method.Name}__{x.Name}()"));
 
+            var parameterArray = parameterTypes == string.Empty
+                ? "Array.Empty<IParameter>()"
+                : $@"new IParameter[]
+            {{
+                {parameterTypes}
+            }}";
+
             var parameterAccessors = string.Join(", ",
                 method.Parameters
                     .Select(
@@ -97,6 +104,13 @@ var parameterNamespaces
                 method.Parameters
                     .Select(x => $"typeof({x.ToDisplayString()})"));
 
+            var reflectionArray = reflectionTypes == string.Empty
+                ? "types: Array.Empty<Type>()"
+                : $@"types: new[]
+                    {{
+                        {reflectionTypes}
+                    }}";
+
             return
 $@"{namespaces}
 
@@ -118,10 +132,7 @@ private static readonly MethodInfo Method
                     bindingAttr: {GetBindingFlags(method)},
                     binder: default,
                     callConvention: {GetCallConv(method)},
-                    types: new[]
-                    {{
-                        {reflectionTypes}
-                    }},
+                    {reflectionArray},
                     modifiers: null)!;
 
         private IReadOnlyDictionary<object, object?>? _data;
@@ -129,10 +140,7 @@ private static readonly MethodInfo Method
         public CommandString Name {{ get; }} = {commandPath};
 
         public IReadOnlyList<IParameter> Parameters {{ get; }}
-            = new IParameter[]
-            {{
-                {parameterTypes}
-            }};
+            = {parameterArray};
 
         public IReadOnlyDictionary<object, object?> Data
         {{