Improve OBject generation

Author: NeonGraal

Diff for: src/GqlPlus.Abstractions/GeneralHelpers.cs

@@ -1,6 +1,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using System.Runtime.CompilerServices;
+using System.Runtime.Serialization;
 using GqlPlus.Structures;
 
 namespace GqlPlus;
@@ -73,13 +74,19 @@ public static string Surround(
     string before,
     string after,
     string by = " ")
-   => before + items.Joined(by) + after;
+  {
+    string inner = items.Joined(by);
+    return string.IsNullOrWhiteSpace(inner) ? "" : before + inner + after;
+  }
 
   public static string Surround<T>(
     this IEnumerable<T>? items,
     string before,
     string after,
     Func<T?, string> formatter,
     string by = " ")
-   => before + items.Joined(formatter, by) + after;
+  {
+    string inner = items.Joined(formatter, by);
+    return string.IsNullOrWhiteSpace(inner) ? "" : before + inner + after;
+  }
 }

Diff for: src/GqlPlus.Generators/Generating/Objects/DualGenerator.cs

@@ -1,7 +1,7 @@
 namespace GqlPlus.Generating.Objects;
 
 internal class DualGenerator
-  : GenerateForObject<IGqlpDualObject>
+  : GenerateForObject<IGqlpDualObject, IGqlpDualBase, IGqlpDualField, IGqlpDualAlternate>
 {
   public override string TypePrefix => "Dual";
 }

Diff for: src/GqlPlus.Generators/Generating/Objects/GenerateForObject.cs

@@ -1,10 +1,15 @@
-namespace GqlPlus.Generating.Objects;
+using GqlPlus.Ast;
 
-internal abstract class GenerateForObject<T>
-  : GenerateForClass<T>
-  where T : IGqlpObject
+namespace GqlPlus.Generating.Objects;
+
+internal abstract class GenerateForObject<TObj, TBase, TField, TAlt>
+  : GenerateForClass<TObj>
+  where TObj : IGqlpObject<TBase, TField, TAlt>
+  where TBase : IGqlpObjBase
+  where TField : IGqlpObjField
+  where TAlt : IGqlpObjAlternate
 {
-  internal override IEnumerable<MapPair<string>> TypeMembers(T ast, GeneratorContext context)
+  internal override IEnumerable<MapPair<string>> TypeMembers(TObj ast, GeneratorContext context)
     => [.. ast.Fields.Select(FieldMember(context)), .. ast.Alternates.Select(AlternateMember(context))];
 
   private Func<IGqlpObjField, MapPair<string>> FieldMember(GeneratorContext context)
@@ -14,5 +19,30 @@ private Func<IGqlpObjAlternate, MapPair<string>> AlternateMember(GeneratorContex
     => alternate => new("As" + alternate.Name, TypeString(alternate, context));
 
   protected virtual string TypeString(IGqlpObjType type, GeneratorContext context)
-    => context.GetTypeAst<IGqlpType>(type.FullType)?.Name ?? type.FullType;
+    => context.GetTypeAst<IGqlpType>(type.Name)?.Name
+      ?? (type.IsTypeParam ? "T" : "") + type.Name;
+
+  protected override void TypeHeader(TObj ast, GeneratorContext context)
+  {
+    string typeParams = ast.TypeParams.Select(p => "T" + p.Name).Surround("<", ">", ",");
+
+    context.AppendLine($"public interface I{ast.Name}{typeParams}");
+    if (ast.Parent is not null) {
+      context.AppendLine("  : I" + ast.Parent.Name);
+    }
+  }
+
+  protected override void ClassHeader(TObj ast, GeneratorContext context)
+  {
+    string typeParams = ast.TypeParams.Select(p => "T" + p.Name).Surround("<", ">", ",");
+
+    context.AppendLine($"public class {TypePrefix}{ast.Name}{typeParams}");
+
+    if (ast.Parent is not null) {
+      context.AppendLine("  : " + TypePrefix + ast.Parent.Name);
+      context.AppendLine("  , I" + ast.Name + typeParams);
+    } else {
+      context.AppendLine("  : I" + ast.Name + typeParams);
+    }
+  }
 }

Diff for: src/GqlPlus.Generators/Generating/Objects/InputGenerator.cs

@@ -1,7 +1,7 @@
 namespace GqlPlus.Generating.Objects;
 
 internal class InputGenerator
-  : GenerateForObject<IGqlpInputObject>
+  : GenerateForObject<IGqlpInputObject, IGqlpInputBase, IGqlpInputField, IGqlpInputAlternate>
 {
   public override string TypePrefix => "Input";
 }

Diff for: src/GqlPlus.Generators/Generating/Objects/OutputGenerator.cs

@@ -1,7 +1,7 @@
 namespace GqlPlus.Generating.Objects;
 
 internal class OutputGenerator
-  : GenerateForObject<IGqlpOutputObject>
+  : GenerateForObject<IGqlpOutputObject, IGqlpOutputBase, IGqlpOutputField, IGqlpOutputAlternate>
 {
   public override string TypePrefix => "Output";
 }

Diff for: src/GqlPlus.Generators/Generating/Simple/GenerateForSimple.cs

@@ -21,7 +21,7 @@ protected override void TypeHeader(T ast, GeneratorContext context)
     base.TypeHeader(ast, context);
 
     if (!string.IsNullOrWhiteSpace(ast.Parent)) {
-      context.AppendLine("  : I" + ast.Name);
+      context.AppendLine("  : I" + ast.Parent);
     }
   }
 }

Diff for: test/GqlPlus.Abstractions.ClassTests/GeneralHelpersTests.cs

@@ -87,22 +87,22 @@ public void Quoted_NullInput_ReturnsEmptyString()
   }
 
   [Fact]
-  public void Surround_NullInput_ReturnsEmptyStringWithSurrounding()
+  public void Surround_NullInput_ReturnsEmptyString()
   {
     IEnumerable<string>? input = null;
 
     string result = input.Surround("[", "]");
 
-    result.ShouldBe("[]");
+    result.ShouldBe("");
   }
 
   [Fact]
-  public void Surround_WithMapping_NullInput_ReturnsEmptyStringWithSurrounding()
+  public void Surround_WithMapping_NullInput_ReturnsEmptyString()
   {
     IEnumerable<int>? input = null;
 
     string result = input.Surround("[", "]", i => $"{i}");
 
-    result.ShouldBe("[]");
+    result.ShouldBe("");
   }
 }