fix(api): Don't render enums twice if they appear in separate objects

Fixes an issue with enums in which they're rendered for each object they appear in, instead of just once.

Author: gkinsman

src/Typescript.Tests/Enums/EnumGeneratorTests.Generator_TypesWithSharedEnum_ShouldOnlyGenerateTheEnumOnce.approved.txt

@@ -0,0 +1,15 @@
+declare namespace Api {
+  interface TypeTwoWithEnum {
+    anEnum: 'FirstEnum' | 'SecondEnum' | 'ThirdEnum';
+  }
+  interface TypeOneWithEnum {
+    anEnum: 'FirstEnum' | 'SecondEnum' | 'ThirdEnum';
+  }
+}
+
+---
+enum SharedEnumType {
+  FirstEnum = 'FirstEnum',
+  SecondEnum = 'SecondEnum',
+  ThirdEnum = 'ThirdEnum',
+}

src/Typescript.Tests/Enums/EnumGeneratorTests.cs

@@ -1,7 +1,6 @@
 using System;
 using Assent;
 using Typescriptr;
-using Typescriptr.Formatters;
 using Xunit;
 
 namespace Typescript.Tests.Enums
@@ -74,5 +73,31 @@ public void Generator_TypeWithEnumAndEnumValueFormatter_RendersValues()
 
             this.Assent(generated.JoinTypesAndEnums());
         }
+
+        
+        class TypeOneWithEnum
+        {
+            public SharedEnumType AnEnum { get; set; }
+        }
+        class TypeTwoWithEnum
+        {
+            public SharedEnumType AnEnum { get; set; }
+        }
+
+        public enum SharedEnumType
+        {
+            FirstEnum,
+            SecondEnum,
+            ThirdEnum
+        }
+        
+        [Fact]
+        public void Generator_TypesWithSharedEnum_ShouldOnlyGenerateTheEnumOnce()
+        {
+            var generator = TypeScriptGenerator.CreateDefault();
+            var generated = generator.Generate(new[] {typeof(TypeOneWithEnum), typeof(TypeTwoWithEnum)});
+
+            this.Assent(generated.JoinTypesAndEnums());
+        }
     }
 }

src/Typescriptr/TypeScriptGenerator.cs

@@ -160,9 +160,10 @@ public GenerationResult Generate(IEnumerable<Type> types)
 
         private void RenderEnum(StringBuilder builder, Type enumType)
         {
+            if (_enumNames.Contains(enumType.FullName)) return;
             var enumString = _enumFormatter(enumType, _quoteStyle);
             builder.Append(enumString);
-            _enumNames.Add(enumType.Name);
+            _enumNames.Add(enumType.FullName);
         }
 
         private void RenderType(StringBuilder builder, Type type)