Adds mapping object to discriminator objects

src/Microsoft.OpenApi.OData.Reader/Generator/OpenApiSchemaGenerator.cs

@@ -397,20 +397,25 @@ private static OpenApiSchema CreateStructuredTypeSchema(this ODataContext contex
             }
             else
             {
+                var structuredTypeName = (structuredType as IEdmSchemaElement)?.Name;
                 // The discriminator object is added to structured types which have derived types.
                 OpenApiDiscriminator discriminator = null;
                 if (context.Settings.EnableDiscriminatorValue && derivedTypes.Any() && structuredType.BaseType != null)
                 {
                     discriminator = new OpenApiDiscriminator
                     {
-                        PropertyName = "@odata.type"
+                        PropertyName = "@odata.type",
+                        Mapping = new Dictionary<string, string>
+                        {
+                            {structuredTypeName, "#" + structuredType.FullTypeName()}
+                        }
                     };
                 }
 
                 // A structured type without a base type is represented as a Schema Object of type object
                 OpenApiSchema schema = new OpenApiSchema
                 {
-                    Title = (structuredType as IEdmSchemaElement)?.Name,
+                    Title = structuredTypeName,
 
                     Type = "object",
 
@@ -425,7 +430,7 @@ private static OpenApiSchema CreateStructuredTypeSchema(this ODataContext contex
                     OneOf = null,
                     AnyOf = null
                 };
-
+              
                 // It optionally can contain the field description,
                 // whose value is the value of the unqualified annotation Core.Description of the structured type.
                 if (structuredType.TypeKind == EdmTypeKind.Complex)

test/Microsoft.OpenAPI.OData.Reader.Tests/Edm/EdmOperationProviderTests.cs

@@ -34,15 +34,15 @@ public void FindOperationsReturnsCorrectCollectionOrOperations()
             var operations = provider.FindOperations(entitySet.EntityType(), false);
 
             // Assert
-            Assert.Equal(15, operations.Count());
+            Assert.Equal(29, operations.Count());
 
             // Act
             entitySet = model.EntityContainer.FindEntitySet("directoryObjects");
 
             operations = provider.FindOperations(entitySet.EntityType(), false);
 
             // Assert
-            Assert.Equal(30, operations.Count());
+            Assert.Equal(57, operations.Count());
         }
     }
 }

test/Microsoft.OpenAPI.OData.Reader.Tests/Edm/ODataPathProviderTests.cs

@@ -48,7 +48,7 @@ public void GetPathsForGraphBetaModelReturnsAllPaths()
 
             // Assert
             Assert.NotNull(paths);
-            Assert.Equal(50085, paths.Count());
+            Assert.Equal(29188, paths.Count());
         }
 
         [Fact]
@@ -67,7 +67,7 @@ public void GetPathsForGraphBetaModelWithDerivedTypesConstraintReturnsAllPaths()
 
             // Assert
             Assert.NotNull(paths);
-            Assert.Equal(50070, paths.Count());
+            Assert.Equal(29154, paths.Count());
         }
 
         [Fact]

test/Microsoft.OpenAPI.OData.Reader.Tests/Generator/OpenApiSchemaGeneratorTests.cs

@@ -80,6 +80,52 @@ public void CreateStructuredTypeSchemaThrowArgumentNullEnumType()
             Assert.Throws<ArgumentNullException>("structuredType", () => context.CreateStructuredTypeSchema(structuredType: null));
         }
 
+        [Fact]
+        public void CreateStructuredTypeSchemaWithDiscriminatorValueEnabledReturnsCorrectSchema()
+        {
+            // Arrange
+            IEdmModel model = EdmModelHelper.GraphBetaModel;
+            ODataContext context = new(model, new OpenApiConvertSettings
+            {
+                EnableDiscriminatorValue = true,
+            });
+
+            IEdmEntityType entity = model.SchemaElements.OfType<IEdmEntityType>().First(t => t.Name == "directoryObject");
+            Assert.NotNull(entity); // Guard
+
+            // Act
+            var schema = context.CreateStructuredTypeSchema(entity);
+            string json = schema.SerializeAsJson(OpenApiSpecVersion.OpenApi3_0);
+
+            // Assert
+            Assert.NotNull(json);
+            Assert.Equal(@"{
+  ""allOf"": [
+    {
+      ""$ref"": ""#/components/schemas/microsoft.graph.entity""
+    },
+    {
+      ""title"": ""directoryObject"",
+      ""type"": ""object"",
+      ""properties"": {
+        ""deletedDateTime"": {
+          ""pattern"": ""^[0-9]{4,}-(0[1-9]|1[012])-(0[1-9]|[12][0-9]|3[01])T([01][0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]([.][0-9]{1,12})?(Z|[+-][0-9][0-9]:[0-9][0-9])$"",
+          ""type"": ""string"",
+          ""format"": ""date-time"",
+          ""nullable"": true
+        }
+      },
+      ""discriminator"": {
+        ""propertyName"": ""@odata.type"",
+        ""mapping"": {
+          ""directoryObject"": ""#microsoft.graph.directoryObject""
+        }
+      }
+    }
+  ]
+}".ChangeLineBreaks(), json);
+        }
+
         [Fact]
         public void CreateComplexTypeWithoutBaseSchemaReturnCorrectSchema()
         {