Test additional cases of imprecise typemapping computation

Author: ranma42

test/EFCore.Cosmos.FunctionalTests/Query/NorthwindMiscellaneousQueryCosmosTest.cs

@@ -3269,6 +3269,38 @@ public override Task Coalesce_Correct_TypeMapping_String(bool async)
 SELECT VALUE ((c["Region"] != null) ? c["Region"] : "no region specified")
 FROM root c
 ORDER BY c["id"]
+""");
+            });
+
+    public override Task Coalesce_Correct_TypeMapping_String_Sum(bool async)
+        => Fixture.NoSyncTest(
+            async, async a =>
+            {
+                await base.Coalesce_Correct_TypeMapping_String_Sum(async);
+
+                AssertSql(
+                    """
+SELECT VALUE ((((c["Region"] != null) ? ("R" || c["Region"]) : null) != null) ? ((c["Region"] != null) ? ("R" || c["Region"]) : null) : "no region specified")
+FROM root c
+ORDER BY c["id"]
+""");
+            });
+
+    public override Task Coalesce_Correct_TypeMapping_String_Join(bool async)
+        => Fixture.NoSyncTest(
+            async, async a =>
+            {
+                await base.Coalesce_Correct_TypeMapping_String_Join(async);
+
+                AssertSql(
+                    """
+SELECT VALUE
+{
+    "c" : (c["Region"] != null),
+    "c0" : ["R", c["Region"]]
+}
+FROM root c
+ORDER BY c["id"]
 """);
             });
 
@@ -3390,7 +3422,7 @@ public override async Task SelectMany_primitive_select_subquery(bool async)
         // Cosmos client evaluation. Issue #17246.
         Assert.Equal(
             CoreStrings.ExpressionParameterizationExceptionSensitive(
-                "value(Microsoft.EntityFrameworkCore.Query.NorthwindMiscellaneousQueryTestBase`1+<>c__DisplayClass175_0[Microsoft.EntityFrameworkCore.Query.NorthwindQueryCosmosFixture`1[Microsoft.EntityFrameworkCore.TestUtilities.NoopModelCustomizer]]).ss.Set().Any()"),
+                "value(Microsoft.EntityFrameworkCore.Query.NorthwindMiscellaneousQueryTestBase`1+<>c__DisplayClass177_0[Microsoft.EntityFrameworkCore.Query.NorthwindQueryCosmosFixture`1[Microsoft.EntityFrameworkCore.TestUtilities.NoopModelCustomizer]]).ss.Set().Any()"),
             (await Assert.ThrowsAsync<InvalidOperationException>(
                 () => base.SelectMany_primitive_select_subquery(async))).Message);
 

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

@@ -748,6 +748,23 @@ public virtual Task Coalesce_Correct_TypeMapping_String(bool async)
             ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Select(c => c.Region ?? "no region specified"),
             assertOrder: true);
 
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))]
+    public virtual Task Coalesce_Correct_TypeMapping_String_Sum(bool async)
+        => AssertQuery(
+            async,
+            ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Select(c => (c.Region != null ? "R" + c.Region : null) ?? "no region specified"),
+            assertOrder: true);
+
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))]
+    public virtual Task Coalesce_Correct_TypeMapping_String_Join(bool async)
+        => AssertQuery(
+            async,
+            ss => ss.Set<Customer>().OrderBy(c => c.CustomerID)
+                .Select(c => (c.Region != null ? string.Join("|", new[] { "R", c.Region }) : null) ?? "no region specified"),
+            assertOrder: true);
+
     [ConditionalTheory]
     [MemberData(nameof(IsAsyncData))]
     public virtual Task Null_Coalesce_Short_Circuit(bool async)

test/EFCore.SqlServer.FunctionalTests/Query/NorthwindMiscellaneousQuerySqlServerTest.cs

@@ -2879,6 +2879,34 @@ ORDER BY [c].[CustomerID]
 """);
     }
 
+    public override async Task Coalesce_Correct_TypeMapping_String_Sum(bool async)
+    {
+        await base.Coalesce_Correct_TypeMapping_String_Sum(async);
+
+        AssertSql(
+            """
+SELECT COALESCE(CASE
+    WHEN [c].[Region] IS NOT NULL THEN N'R' + [c].[Region]
+END, N'no region specified')
+FROM [Customers] AS [c]
+ORDER BY [c].[CustomerID]
+""");
+    }
+
+    public override async Task Coalesce_Correct_TypeMapping_String_Join(bool async)
+    {
+        await base.Coalesce_Correct_TypeMapping_String_Join(async);
+
+        AssertSql(
+            """
+SELECT COALESCE(CASE
+    WHEN [c].[Region] IS NOT NULL THEN CONCAT_WS(N'|', N'R', [c].[Region])
+END, N'no region specified')
+FROM [Customers] AS [c]
+ORDER BY [c].[CustomerID]
+""");
+    }
+
     public override async Task Null_Coalesce_Short_Circuit(bool async)
     {
         await base.Null_Coalesce_Short_Circuit(async);