Capitalize database name (#27966)

When scaffolding from a database the database name is modified in order to respect .NET conventions

#Fixes 27886

Author: ilmalte

src/EFCore.Design/Scaffolding/Internal/CandidateNamingService.cs

@@ -65,7 +65,13 @@ public virtual string GetPrincipalEndCandidateNavigationPropertyName(
             : foreignKey.DeclaringEntityType.ShortName();
     }
 
-    private static string GenerateCandidateIdentifier(string originalIdentifier)
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual string GenerateCandidateIdentifier(string originalIdentifier)
     {
         var candidateStringBuilder = new StringBuilder();
         var previousLetterCharInWordIsLowerCase = false;

src/EFCore.Design/Scaffolding/Internal/ICandidateNamingService.cs

@@ -29,6 +29,15 @@ public interface ICandidateNamingService
     /// </summary>
     string GenerateCandidateIdentifier(DatabaseColumn originalColumn);
 
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    string GenerateCandidateIdentifier(string databaseName);
+
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in

src/EFCore.Design/Scaffolding/Internal/RelationalScaffoldingModelFactory.cs

@@ -166,7 +166,10 @@ protected virtual ModelBuilder VisitDatabaseModel(ModelBuilder modelBuilder, Dat
 
         if (!string.IsNullOrEmpty(databaseModel.DatabaseName))
         {
-            modelBuilder.Model.SetDatabaseName(databaseModel.DatabaseName);
+            modelBuilder.Model.SetDatabaseName(
+                            !_options.UseDatabaseNames && !string.IsNullOrEmpty(databaseModel.DatabaseName)
+                    ? _candidateNamingService.GenerateCandidateIdentifier(databaseModel.DatabaseName)
+                        : databaseModel.DatabaseName);
         }
 
         if (!string.IsNullOrEmpty(databaseModel.Collation))

test/EFCore.Design.Tests/Scaffolding/Internal/RelationalScaffoldingModelFactoryTest.cs

@@ -50,6 +50,14 @@ public RelationalScaffoldingModelFactoryTest()
         _reporter.Clear();
     }
 
+    [ConditionalFact]
+    public void Capitalize_DatabaseName()
+    {
+        var database = new DatabaseModel { DatabaseName = "northwind" };
+        var model = _factory.Create(database, new ModelReverseEngineerOptions { UseDatabaseNames = false });
+        Assert.Equal("Northwind", model.GetDatabaseName());
+    }
+
     [ConditionalFact]
     public void Creates_entity_types()
     {
@@ -131,6 +139,27 @@ public void Creates_entity_types_case_insensitive()
         Assert.Equal(2, model.GetEntityTypes().Select(et => et.Name).Distinct(StringComparer.OrdinalIgnoreCase).Count());
     }
 
+    [ConditionalTheory]
+    [InlineData("PascalCase")]
+    [InlineData("camelCase")]
+    [InlineData("snake-case")]
+    [InlineData("MixedCASE")]
+    [InlineData("separated_by_underscores")]
+    [InlineData("PascalCase_withUnderscore")]
+    [InlineData("ALL_CAPS")]
+    [InlineData("numbers0Dont1Affect23Upper45Case678To9LowerCase10Boundary999")]
+    [InlineData("We1!*~&%rdCh@r^act()0rs")]
+    public void Get_DatabaseName(string expectedValue)
+    {
+        var options = new ModelReverseEngineerOptions { UseDatabaseNames = true };
+
+        var database = new DatabaseModel { DatabaseName = expectedValue };
+        var model = _factory.Create(database, options);
+        Assert.Equal(expectedValue, model.GetDatabaseName());
+
+    }
+
+
     [ConditionalFact]
     public void Loads_column_types()
     {