Fix non-deterministic tests that fail on postgres

test/EFCore.InMemory.FunctionalTests/Query/Ef6GroupByInMemoryTest.cs

@@ -16,7 +16,8 @@ public override Task Average_Grouped_from_LINQ_101(bool async)
             ss => from p in ss.Set<ProductForLinq>()
                   group p by p.Category
                   into g
-                  select new { Category = g.Key, AveragePrice = g.Average(p => p.UnitPrice) });
+                  select new { Category = g.Key, AveragePrice = g.Average(p => p.UnitPrice) },
+            elementSorter: e => (e.Category, e.AveragePrice));
 
     public class Ef6GroupByInMemoryFixture : Ef6GroupByFixtureBase
     {

test/EFCore.Specification.Tests/Query/Ef6GroupByTestBase.cs

@@ -413,7 +413,8 @@ into g
             ss => from p in ss.Set<ProductForLinq>()
                   group p by p.Category
                   into g
-                  select new { Category = g.Key, AveragePrice = Math.Round(g.Average(p => p.UnitPrice) - 0.0000005m, 6) });
+                  select new { Category = g.Key, AveragePrice = Math.Round(g.Average(p => p.UnitPrice) - 0.0000005m, 6) },
+            elementSorter: e => (e.Category, e.AveragePrice));
 
     [ConditionalTheory]
     [MemberData(nameof(IsAsyncData))]

test/EFCore.Specification.Tests/Query/NorthwindSelectQueryTestBase.cs

@@ -846,7 +846,7 @@ public virtual Task Reverse_in_subquery_via_pushdown(bool async)
                 .Take(5)
                 .Distinct()
                 .Select(e => new { e.EmployeeID, e.City }),
-            assertOrder: true);
+            elementSorter: e => e.EmployeeID);
 
     [ConditionalTheory]
     [MemberData(nameof(IsAsyncData))]

test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs

@@ -771,9 +771,21 @@ public virtual async Task Aggregate_over_subquery_in_group_by_projection(bool as
             ? await query.ToListAsync()
             : query.ToList();
 
-        Assert.Collection(orders,
-            t => Assert.Equal(10, t.CustomerMinHourlyRate),
-            t => Assert.Equal(20, t.CustomerMinHourlyRate));
+        Assert.Collection(orders.OrderBy(x => x.CustomerId),
+            t =>
+            {
+                Assert.Equal(1, t.CustomerId);
+                Assert.Equal(10, t.CustomerMinHourlyRate);
+                Assert.Equal(11, t.HourlyRate);
+                Assert.Equal(1, t.Count);
+            },
+            t =>
+            {
+                Assert.Equal(2, t.CustomerId);
+                Assert.Equal(20, t.CustomerMinHourlyRate);
+                Assert.Equal(20, t.HourlyRate);
+                Assert.Equal(1, t.Count);
+            });
     }
 
     protected class Context27083 : DbContext