Issue in generation of C# classes with inheritance fixed (#1319)

* Bug in JsonReferenceResolver fixed which prevented the referencing of definitions in other files.

* Issue in the JsonSchemaAppender for the generation of classes fixed when the definitions reference the root schema. When the passed schema is already the root schema the method returns immediately instead of throwing an exception.

Issue in the CSharpTypeResolver for the generation of base classes without properties fixed. When classes don't contain properties but contain the "descriminator" attribute they should still be generated.

Co-authored-by: Egli, Florian {DMMA~Rotkreuz-Tro} <[email protected]>

src/NJsonSchema.CodeGeneration.CSharp.Tests/InheritanceTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
+using System.IO;
+using System.Reflection;
 using System.Runtime.Serialization;
 using System.Threading.Tasks;
 using Newtonsoft.Json;
@@ -132,5 +133,33 @@ public async Task When_property_references_any_schema_with_inheritance_then_prop
             //// Assert
             Assert.Contains("public Dog Dog { get; set; }", code);
         }
+
+        [Fact]
+        public async Task When_definitions_inherit_from_root_schema()
+        {
+            //// Arrange
+            var path = GetTestDirectory() + "/References/Animal.json";
+
+            //// Act
+            var schema = await JsonSchema.FromFileAsync(path);
+            var generator = new CSharpGenerator(schema, new CSharpGeneratorSettings { ClassStyle = CSharpClassStyle.Record });
+
+            //// Act
+            var code = generator.GenerateFile();
+
+            //// Assert
+            Assert.Contains("public abstract partial class Animal", code);
+            Assert.Contains("public partial class Cat : Animal", code);
+            Assert.Contains("public partial class PersianCat : Cat", code);
+            Assert.Contains("[JsonInheritanceAttribute(\"Cat\", typeof(Cat))]", code);
+            Assert.Contains("[JsonInheritanceAttribute(\"PersianCat\", typeof(PersianCat))]", code);
+        }
+
+        private string GetTestDirectory()
+        {
+            var codeBase = Assembly.GetExecutingAssembly().CodeBase;
+            var uri = new UriBuilder(codeBase);
+            return Path.GetDirectoryName(Uri.UnescapeDataString(uri.Path));
+        }
     }
 }

src/NJsonSchema.CodeGeneration.CSharp.Tests/NJsonSchema.CodeGeneration.CSharp.Tests.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
   <ItemGroup>
     <None Remove="References\A.json" />
+    <None Remove="References\Animal.json" />
     <None Remove="References\B.json" />
     <None Remove="References\C.json" />
     <None Remove="References\D.json" />
@@ -16,6 +17,9 @@
     <Content Include="References\A.json">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Content>
+    <Content Include="References\Animal.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
     <Content Include="References\B.json">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Content>

src/NJsonSchema.CodeGeneration.CSharp.Tests/References/Animal.json

@@ -0,0 +1,25 @@
+{
+    "title": "Animal",
+    "type": "object",
+    "x-abstract": true,
+    "discriminator": "discriminator",
+
+    "definitions": {
+        "Cat": {
+            "type": "object",
+            "allOf": [
+                {
+                    "$ref": "Animal.json"
+                }
+            ]
+        },
+        "PersianCat": {
+            "type": "object",
+            "allOf": [
+                {
+                    "$ref": "#/definitions/Cat"
+                }
+            ]
+        }
+    }
+}

src/NJsonSchema.CodeGeneration.CSharp/CSharpTypeResolver.cs

@@ -78,6 +78,7 @@ schema is JsonSchemaProperty property &&
             var markAsNullableType = Settings.GenerateNullableReferenceTypes && isNullable;
 
             if (schema.ActualTypeSchema.IsAnyType &&
+                schema.ActualDiscriminator == null &&
                 schema.InheritedSchema == null && // not in inheritance hierarchy
                 schema.AllOf.Count == 0 &&
                 !Types.Keys.Contains(schema) &&

src/NJsonSchema/JsonSchemaAppender.cs

@@ -44,7 +44,7 @@ public virtual void AppendSchema(JsonSchema schema, string typeNameHint)
 
             if (schema == RootObject)
             {
-                throw new ArgumentException("The root schema cannot be appended.");
+                return;
             }
 
             if (!RootSchema.Definitions.Values.Contains(schema))