Fix relation enumeration naming for 0.10 (breaking change)

src/DataLinq.Tests.Compliance/Relations/EmployeesRelationAndThreadingTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using DataLinq.Instances;
 using DataLinq.Tests.Models.Employees;
 using DataLinq.Testing;
 
@@ -53,6 +54,22 @@ public async Task Relations_DepartmentManagersLazyLoad_ResolvesCollection(TestPr
 
         await Assert.That(department.Managers).IsNotEmpty();
         await Assert.That(department.Managers.All(x => x.Department.DeptNo == department.Department.DeptNo)).IsTrue();
+
+        var relation = department.Department.Managers;
+        IEnumerable<Manager> rows = relation.AsEnumerable();
+        var expectedByKey = rows.ToDictionary(manager => manager.PrimaryKeys());
+
+        // Manager keys are composite; keyed enumeration must not use the parent department key.
+        relation.Clear();
+        IEnumerable<KeyValuePair<DataLinqKey, Manager>> keyedRows = relation.AsKeyValuePairs();
+        var pairs = keyedRows.ToArray();
+        await Assert.That(pairs.Length).IsEqualTo(expectedByKey.Count);
+        foreach (var pair in pairs)
+        {
+            await Assert.That(pair.Key).IsEqualTo(DataLinqKey.FromValues([pair.Value.dept_fk, pair.Value.emp_no]));
+            await Assert.That(ReferenceEquals(pair.Value, expectedByKey[pair.Key])).IsTrue();
+            await Assert.That(ReferenceEquals(relation.Get(pair.Key), pair.Value)).IsTrue();
+        }
     }
 
     [Test]

src/DataLinq.Tests.Compliance/Relations/MultipleForeignKeyRelationTests.cs

@@ -1,6 +1,8 @@
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using DataLinq.Attributes;
+using DataLinq.Diagnostics;
 using DataLinq.Instances;
 using DataLinq.Interfaces;
 using DataLinq.Metadata;
@@ -12,6 +14,7 @@ namespace DataLinq.Tests.Compliance;
 public class MultipleForeignKeyRelationTests
 {
     [Test]
+    [NotInParallel]
     [Property(TestProviderAffinity.PropertyName, TestProviderAffinity.EveryProvider)]
     [MethodDataSource(typeof(TestProviderDataSources), nameof(TestProviderDataSources.ActiveProviders))]
     public async Task Transaction_MultipleForeignKeysToSameTable_LazyLoadsDistinctRelations(TestProviderDescriptor provider)
@@ -40,18 +43,46 @@ public async Task Transaction_MultipleForeignKeysToSameTable_LazyLoadsDistinctRe
         await Assert.That(ReferenceEquals(createdBy, creator)).IsTrue();
         await Assert.That(ReferenceEquals(approvedBy, approver)).IsTrue();
 
-        var createdInvoices = creator.CreatedInvoices.ToArray();
+        var relation = creator.CreatedInvoices;
+        var concreteRelation = (ImmutableRelation<RuntimeInvoice, int>)relation;
+        var loadsBeforeRowViews = GetCollectionLoads(databaseScope.Database);
+
+        // Both receiver types must bind to the standard row extension without loading.
+        IEnumerable<RuntimeInvoice> rows = relation.AsEnumerable();
+        IEnumerable<RuntimeInvoice> concreteRows = concreteRelation.AsEnumerable();
+
+        await Assert.That(ReferenceEquals(rows, relation)).IsTrue();
+        await Assert.That(ReferenceEquals(concreteRows, relation)).IsTrue();
+        await Assert.That(GetCollectionLoads(databaseScope.Database)).IsEqualTo(loadsBeforeRowViews);
+
+        var createdInvoices = rows.ToArray();
+        await Assert.That(GetCollectionLoads(databaseScope.Database)).IsEqualTo(loadsBeforeRowViews + 1);
         var approvedInvoices = approver.ApprovedInvoices.ToArray();
 
         await Assert.That(createdInvoices.Length).IsEqualTo(1);
         await Assert.That(approvedInvoices.Length).IsEqualTo(1);
         await Assert.That(ReferenceEquals(invoice, createdInvoices.Single())).IsTrue();
         await Assert.That(ReferenceEquals(invoice, approvedInvoices.Single())).IsTrue();
-        await Assert.That(creator.ApprovedInvoices).IsEmpty();
-        await Assert.That(approver.CreatedInvoices).IsEmpty();
+
+        IEnumerable<KeyValuePair<DataLinqKey, RuntimeInvoice>> keyedRows = relation.AsKeyValuePairs();
+        var pair = keyedRows.Single();
+        await Assert.That(pair.Key).IsEqualTo(DataLinqKey.FromValue(100));
+        await Assert.That(ReferenceEquals(pair.Value, createdInvoices.Single())).IsTrue();
+        await Assert.That(ReferenceEquals(relation.Get(pair.Key), pair.Value)).IsTrue();
+        await Assert.That(ReferenceEquals(concreteRelation.AsKeyValuePairs().Single().Value, pair.Value)).IsTrue();
+
+        await Assert.That(creator.ApprovedInvoices.AsEnumerable()).IsEmpty();
+        await Assert.That(creator.ApprovedInvoices.AsKeyValuePairs()).IsEmpty();
+        await Assert.That(approver.CreatedInvoices.AsEnumerable()).IsEmpty();
+        await Assert.That(approver.CreatedInvoices.AsKeyValuePairs()).IsEmpty();
 
         transaction.Commit();
     }
+
+    private static long GetCollectionLoads(Database<MultipleForeignKeyRelationDb> database)
+        => DataLinqMetrics.Snapshot().Providers
+            .Single(provider => provider.ProviderInstanceId == database.Provider.TelemetryInstanceId)
+            .Tables.Sum(table => table.Relations.CollectionLoads);
 }
 
 [Database("multiple_fk_relation")]

src/DataLinq/Instances/ImmutableRelation.cs

@@ -21,7 +21,11 @@ public interface IImmutableRelation<T> : IEnumerable<T> where T : IModelInstance
     ImmutableArray<DataLinqKey> Keys { get; }
     ImmutableArray<T> Values { get; }
 
-    IEnumerable<KeyValuePair<DataLinqKey, T>> AsEnumerable();
+    /// <summary>
+    /// Returns relation rows paired with their primary keys.
+    /// Resolving the keyed collection may synchronously load the relation.
+    /// </summary>
+    IEnumerable<KeyValuePair<DataLinqKey, T>> AsKeyValuePairs();
     void Clear();
     bool Any() => Count != 0;
 
@@ -100,7 +104,7 @@ public ImmutableRelationMock(IEnumerable<T> list)
 
     public ImmutableArray<T> Values => throw new System.NotImplementedException();
 
-    public IEnumerable<KeyValuePair<DataLinqKey, T>> AsEnumerable()
+    public IEnumerable<KeyValuePair<DataLinqKey, T>> AsKeyValuePairs()
     {
         throw new System.NotImplementedException();
     }
@@ -172,7 +176,8 @@ public class ImmutableRelation<T, TKey>(TKey foreignKey, IDataSourceAccess dataS
     public ImmutableArray<DataLinqKey> Keys => GetInstances().Keys;
     public int Count => GetValues().Length;
     public bool ContainsKey(DataLinqKey key) => GetInstances().ContainsKey(key);
-    public IEnumerable<KeyValuePair<DataLinqKey, T>> AsEnumerable() => GetInstances().AsEnumerable();
+    /// <inheritdoc />
+    public IEnumerable<KeyValuePair<DataLinqKey, T>> AsKeyValuePairs() => GetInstances().AsEnumerable();
     public FrozenDictionary<DataLinqKey, T> ToFrozenDictionary() => GetInstances();
 
     protected TableCache GetTableCache() => GetTableCache(GetDataSource());