feat(#141): add support for link entities using the exists join operator

CHANGELOG.md

@@ -1,3 +1,9 @@
+## [2.7.0]
+
+### Added
+
+- Added support for link entities that use the `Exists` join operator - https://github.com/DynamicsValue/fake-xrm-easy/issues/141
+
 ## [2.6.0]
 
 ### Added

src/FakeXrmEasy.Core/FakeXrmEasy.Core.csproj

@@ -25,6 +25,7 @@
 		<SignAssembly>True</SignAssembly>
     <PublicSign Condition="'$(OS)'=='Unix'">true</PublicSign>
     <SonarQubeTestProject>False</SonarQubeTestProject>
+    <Version>2.7.0</Version>
   </PropertyGroup>
 
   <ItemGroup>

src/FakeXrmEasy.Core/Query/LinkEntityQueryExtensions.cs

@@ -87,8 +87,16 @@ internal static IQueryable<Entity> ToQueryable(this LinkEntity le, IXrmFakedCont
                                                             , (x, y) => x.outerEl
                                                                             .JoinAttributes(y, new ColumnSet(true), leAlias, context));
 
-
                     break;
+#if FAKE_XRM_EASY_9
+                case JoinOperator.Exists:
+                    // This is most likely not the most performant implementation, but it is probably the closest match
+                    // to the generated sql query, which will be a correlated subquery.
+                    query = query.Where(outerEl => 
+                        inner.Any(innerEl => 
+                            outerEl.KeySelector(linkFromAlias, context).Equals(innerEl.KeySelector(le.LinkToAttributeName, context))));
+                    break;
+#endif
                 default: //This shouldn't be reached as there are only 3 types of Join...
                     throw UnsupportedExceptionFactory.New(context.LicenseContext.Value, string.Format("The join operator {0} is currently not supported. ", le.JoinOperator));
 

tests/FakeXrmEasy.Core.Tests/Middleware/Crud/FakeMessageExecutors/RetrieveMultipleRequestTests/QueryLinkEntityTests.cs

@@ -1127,5 +1127,101 @@ public void TestRetriveMultipleWithLinkEntityWithAlternateNullField()
             // this fails (entity2Value is "value")
             Assert.Null(entity2Value);
         }
+
+        [Fact]
+        public void Should_Find_Record_With_Associations_When_Exists_Join_Is_Used()
+        {
+            // Arrange
+            Entity account = new Entity("account", Guid.NewGuid());
+
+            Entity contact = new Entity("contact", Guid.NewGuid())
+            {
+                ["parentcustomerid"] = account.ToEntityReference(),
+            };
+            List<Entity> entities = new List<Entity>()
+            {
+                account, contact
+            };
+
+            _context.Initialize(entities);
+
+            QueryExpression queryExpression = new QueryExpression("account");
+            queryExpression.ColumnSet = new ColumnSet(true);
+
+            LinkEntity contactQuery = queryExpression.AddLink("contact", "accountid", "parentcustomerid");
+            contactQuery.JoinOperator = JoinOperator.Exists;
+            contactQuery.EntityAlias = "c";
+
+            // Act
+            EntityCollection results = _service.RetrieveMultiple(queryExpression);
+
+            // Assert
+            Assert.Single(results.Entities);
+        }
+
+
+        [Fact]
+        public void Should_Not_Find_Record_Without_Associations_When_Exists_Join_Is_Used()
+        {
+            // Arrange
+            Entity account = new Entity("account", Guid.NewGuid());
+
+            Entity contact = new Entity("contact", Guid.NewGuid());
+            List<Entity> entities = new List<Entity>()
+            {
+                account, contact
+            };
+
+            _context.Initialize(entities);
+
+            QueryExpression queryExpression = new QueryExpression("account");
+            queryExpression.ColumnSet = new ColumnSet(true);
+
+            LinkEntity contactQuery = queryExpression.AddLink("contact", "accountid", "parentcustomerid");
+            contactQuery.JoinOperator = JoinOperator.Exists;
+            contactQuery.EntityAlias = "c";
+
+            // Act
+            EntityCollection result = _service.RetrieveMultiple(queryExpression);
+
+            // Assert
+            Assert.Empty(result.Entities);
+        }
+
+        [Fact]
+        public void Should_Return_Only_Outer_Record_When_Exists_Join_Is_Used()
+        {
+            // Arrange
+            Entity account = new Entity("account", Guid.NewGuid());
+
+            Entity contact = new Entity("contact", Guid.NewGuid())
+            {
+                ["parentcustomerid"] = account.ToEntityReference(),
+                ["firstname"] = "firstname"
+            };
+            List<Entity> entities = new List<Entity>()
+            {
+                account, contact
+            };
+
+            _context.Initialize(entities);
+
+            QueryExpression queryExpression = new QueryExpression("account");
+            queryExpression.ColumnSet = new ColumnSet(true);
+
+            LinkEntity contactQuery = queryExpression.AddLink("contact", "accountid", "parentcustomerid");
+            contactQuery.JoinOperator = JoinOperator.Exists;
+            contactQuery.EntityAlias = "c";
+            contactQuery.Columns = new ColumnSet(true);
+
+            // Act
+            EntityCollection result = _service.RetrieveMultiple(queryExpression);
+
+            // Assert
+            Assert.Single(result.Entities);
+
+            Entity outerRecord = result.Entities.First();
+            Assert.Null(outerRecord.GetAttributeValue<AliasedValue>("c.firstname"));
+        }
     }
 }