Rework tests from 1-to-1 mapping into specifications (#46)

CliFx.Tests/DependencyInjectionSpecs.Commands.cs

@@ -0,0 +1,37 @@
+using System.Threading.Tasks;
+using CliFx.Attributes;
+
+namespace CliFx.Tests
+{
+    public partial class DependencyInjectionSpecs
+    {
+        [Command]
+        private class WithoutDependenciesCommand : ICommand
+        {
+            public ValueTask ExecuteAsync(IConsole console) => default;
+        }
+
+        private class DependencyA
+        {
+        }
+
+        private class DependencyB
+        {
+        }
+
+        [Command]
+        private class WithDependenciesCommand : ICommand
+        {
+            private readonly DependencyA _dependencyA;
+            private readonly DependencyB _dependencyB;
+
+            public WithDependenciesCommand(DependencyA dependencyA, DependencyB dependencyB)
+            {
+                _dependencyA = dependencyA;
+                _dependencyB = dependencyB;
+            }
+
+            public ValueTask ExecuteAsync(IConsole console) => default;
+        }
+    }
+}