Use directly annotated CountRestriction annotations when creating $count segments for col-valued navigation properties (#374)

* Get the directly annotated restriction annotation of the navigation property

* Update tests and integration file

* Update release notes

* Add unit test

Author: irvinesunday

src/Microsoft.OpenApi.OData.Reader/Edm/ODataPathProvider.cs

@@ -484,18 +484,28 @@ private void RetrieveNavigationPropertyPaths(
             {
                 IEdmEntityType navEntityType = navigationProperty.ToEntityType();
                 var targetsMany = navigationProperty.TargetMultiplicity() == EdmMultiplicity.Many;
-                var propertyPath = navigationProperty.GetPartnerPath()?.Path;
-                var propertyPathIsEmpty = string.IsNullOrEmpty(propertyPath);
-
-                if (targetsMany) 
+                
+                if (targetsMany)
                 {
-                    if(propertyPathIsEmpty ||
-                        (count?.IsNonCountableNavigationProperty(propertyPath) ?? true))
+                    bool? createCountPath = null;
+                    if (count == null)
+                    {
+                        // First, get the directly annotated restriction annotation of the navigation property
+                        count = _model.GetRecord<CountRestrictionsType>(navigationProperty, CapabilitiesConstants.CountRestrictions);
+                        createCountPath = count?.Countable;
+                    }
+
+                    var propertyPath = navigationProperty.GetPartnerPath()?.Path;
+                    createCountPath ??= string.IsNullOrEmpty(propertyPath)
+                        || (count?.IsNonCountableNavigationProperty(propertyPath) ?? true);
+
+                    if (createCountPath.Value)
                     {
                         // ~/entityset/{key}/collection-valued-Nav/$count
                         CreateCountPath(currentPath, convertSettings);
                     }
                 }
+
                 // ~/entityset/{key}/collection-valued-Nav/subtype
                 // ~/entityset/{key}/single-valued-Nav/subtype
                 CreateTypeCastPaths(currentPath, convertSettings, navEntityType, navigationProperty, targetsMany);

src/Microsoft.OpenApi.OData.Reader/Microsoft.OpenAPI.OData.Reader.csproj

@@ -15,7 +15,7 @@
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <PackageId>Microsoft.OpenApi.OData</PackageId>
     <SignAssembly>true</SignAssembly>
-    <Version>1.4.0-preview3</Version>
+    <Version>1.4.0-preview4</Version>
     <Description>This package contains the codes you need to convert OData CSDL to Open API Document of Model.</Description>
     <Copyright>© Microsoft Corporation. All rights reserved.</Copyright>
     <PackageTags>Microsoft OpenApi OData EDM</PackageTags>
@@ -24,6 +24,7 @@
 - DELETE methods should always return response status code #204
 - Aliases or strips namespace prefixes from segment names when and where applicable #365
 - Adds support for all Org.OData.Core.V1.RevisionKind enum values #372
+- Use directly annotated CountRestriction annotations when creating $count segments for collection-valued navigation properties #328
     </PackageReleaseNotes>
     <AssemblyName>Microsoft.OpenApi.OData.Reader</AssemblyName>
     <AssemblyOriginatorKeyFile>..\..\tool\Microsoft.OpenApi.OData.snk</AssemblyOriginatorKeyFile>

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

@@ -52,7 +52,7 @@ public void GetPathsForGraphBetaModelReturnsAllPaths()
 
             // Assert
             Assert.NotNull(paths);
-            Assert.Equal(18054, paths.Count());
+            Assert.Equal(18050, paths.Count());
             AssertGraphBetaModelPaths(paths);
         }
 
@@ -64,6 +64,9 @@ private void AssertGraphBetaModelPaths(IEnumerable<ODataPath> paths)
 
             // Test that $value segments are created for entity types with base types with HasStream="true"
             Assert.NotNull(paths.FirstOrDefault(p => p.GetPathItemName().Equals("/me/chats({id})/messages({id1})/hostedContents({id2})/$value")));
+
+            // Test that count restrictions annotations for navigation properties work
+            Assert.Null(paths.FirstOrDefault(p => p.GetPathItemName().Equals("/me/drives/$count")));
         }
 
         [Fact]
@@ -84,7 +87,50 @@ public void GetPathsForGraphBetaModelWithDerivedTypesConstraintReturnsAllPaths()
 
             // Assert
             Assert.NotNull(paths);
-            Assert.Equal(18705, paths.Count());
+            Assert.Equal(18701, paths.Count());
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, false)]
+        public void UseCountRestrictionsAnnotationsToAppendDollarCountSegmentsToNavigationPropertyPaths(bool useCountRestrictionsAnnotation, bool countable)
+        {
+            // Arrange
+            string countRestrictionAnnotation = @"
+<Annotation Term=""Org.OData.Capabilities.V1.CountRestrictions"">
+    <Record>
+        <PropertyValue Property=""Countable"" Bool=""{0}"" />
+    </Record>
+</Annotation>";
+            countRestrictionAnnotation = string.Format(countRestrictionAnnotation, countable);
+            IEdmModel model = useCountRestrictionsAnnotation ? GetNavPropModel(countRestrictionAnnotation)
+                : GetNavPropModel(string.Empty);
+            ODataPathProvider provider = new();
+            var settings = new OpenApiConvertSettings();
+
+            // Act
+            var paths = provider.GetPaths(model, settings);
+
+            // Assert
+            Assert.NotNull(paths);
+            var testPath = paths.FirstOrDefault(p => p.GetPathItemName().Equals("/Root/Customers/$count"));
+
+            if (useCountRestrictionsAnnotation)
+            {
+                if (countable)
+                {
+                    Assert.NotNull(testPath);
+                }                    
+                else
+                {
+                    Assert.Null(testPath);
+                }                    
+            }
+            else
+            {
+                Assert.NotNull(testPath);
+            }
         }
 
         [Fact]

test/Microsoft.OpenAPI.OData.Reader.Tests/Resources/Graph.Beta.OData.xml

@@ -112362,6 +112362,13 @@
       <Term Name="teamCreationMode" Type="Edm.String" AppliesTo="microsoft.graph.team">
         <Annotation Term="Org.OData.Core.V1.LongDescription" String="Indicates that the team is in migration state and is currently being used for migration purposes. It accepts one value: migration. Note: In the future, Microsoft may require you or your customers to pay additional fees based on the amount of data imported." />
       </Term>
+	  <Annotations Target="microsoft.graph.user/drives">
+        <Annotation Term="Org.OData.Capabilities.V1.CountRestrictions">
+          <Record>
+            <PropertyValue Property="Countable" Bool="false" />
+          </Record>
+        </Annotation>
+      </Annotations>
       <Annotations Target="microsoft.graph.user/joinedGroups">
         <Annotation Term="Org.OData.Capabilities.V1.NavigationRestrictions">
           <Record>