Fix indentation when scaffolding with no namespace

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

@@ -261,15 +261,9 @@ protected virtual void GenerateOnConfiguring(
                 {
                     if (!suppressConnectionStringWarning)
                     {
-                        _builder.DecrementIndent()
-                            .DecrementIndent()
-                            .DecrementIndent()
-                            .DecrementIndent()
-                            .AppendLine("#warning " + DesignStrings.SensitiveInformationWarning)
-                            .IncrementIndent()
-                            .IncrementIndent()
-                            .IncrementIndent()
-                            .IncrementIndent();
+                        using var _ = _builder.SuspendIndent();
+
+                        _builder.AppendLine("#warning " + DesignStrings.SensitiveInformationWarning);
                     }
 
                     var useProviderCall = _providerConfigurationCodeGenerator.GenerateUseProvider(

src/EFCore/Infrastructure/IndentedStringBuilder.cs

@@ -215,6 +215,13 @@ public virtual IndentedStringBuilder DecrementIndent()
         public virtual IDisposable Indent()
             => new Indenter(this);
 
+        /// <summary>
+        ///     Temporarily disables all indentation. Restores the original indentation when the returned object is disposed.
+        /// </summary>
+        /// <returns> An object that restores the original indentation when disposed. </returns>
+        public virtual IDisposable SuspendIndent()
+            => new IndentSuspender(this);
+
         /// <summary>
         ///     Returns the built string.
         /// </summary>
@@ -246,5 +253,21 @@ public Indenter(IndentedStringBuilder stringBuilder)
             public void Dispose()
                 => _stringBuilder.DecrementIndent();
         }
+
+        private sealed class IndentSuspender : IDisposable
+        {
+            private readonly IndentedStringBuilder _stringBuilder;
+            private readonly byte _indent;
+
+            public IndentSuspender(IndentedStringBuilder stringBuilder)
+            {
+                _stringBuilder = stringBuilder;
+                _indent = _stringBuilder._indent;
+                _stringBuilder._indent = 0;
+            }
+
+            public void Dispose()
+                => _stringBuilder._indent = _indent;
+        }
     }
 }

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

@@ -56,9 +56,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             if (!optionsBuilder.IsConfigured)
             {
-#warning "
-                        + DesignStrings.SensitiveInformationWarning
-                        + @"
+#warning " + DesignStrings.SensitiveInformationWarning + @"
                 optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
             }
         }
@@ -639,9 +637,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             if (!optionsBuilder.IsConfigured)
             {
-#warning "
-                        + DesignStrings.SensitiveInformationWarning
-                        + @"
+#warning " + DesignStrings.SensitiveInformationWarning + @"
                 optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
             }
         }
@@ -721,9 +717,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             if (!optionsBuilder.IsConfigured)
             {
-#warning "
-                        + DesignStrings.SensitiveInformationWarning
-                        + @"
+#warning " + DesignStrings.SensitiveInformationWarning + @"
                 optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
             }
         }
@@ -806,9 +800,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             if (!optionsBuilder.IsConfigured)
             {
-#warning "
-                        + DesignStrings.SensitiveInformationWarning
-                        + @"
+#warning " + DesignStrings.SensitiveInformationWarning + @"
                 optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
             }
         }
@@ -887,9 +879,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             if (!optionsBuilder.IsConfigured)
             {
-#warning "
-                        + DesignStrings.SensitiveInformationWarning
-                        + @"
+#warning " + DesignStrings.SensitiveInformationWarning + @"
                 optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
             }
         }
@@ -941,13 +931,52 @@ public void Global_namespace_works()
         {
             Test(
                 modelBuilder => modelBuilder.Entity("MyEntity"),
-                new ModelCodeGenerationOptions
-                {
-                    ModelNamespace = string.Empty
-                },
+                new ModelCodeGenerationOptions { ModelNamespace = string.Empty },
                 code =>
                 {
-                    Assert.DoesNotContain("namespace ", code.ContextFile.Code);
+                    AssertFileContents(
+                        @"using System;
+using System.Collections.Generic;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+public partial class TestDbContext : DbContext
+{
+    public TestDbContext()
+    {
+    }
+
+    public TestDbContext(DbContextOptions<TestDbContext> options)
+        : base(options)
+    {
+    }
+
+    public virtual DbSet<MyEntity> MyEntity { get; set; }
+
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+    {
+        if (!optionsBuilder.IsConfigured)
+        {
+#warning " + DesignStrings.SensitiveInformationWarning + @"
+            optionsBuilder.UseSqlServer(""Initial Catalog=TestDatabase"");
+        }
+    }
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.Entity<MyEntity>(entity =>
+        {
+            entity.HasNoKey();
+        });
+
+        OnModelCreatingPartial(modelBuilder);
+    }
+
+    partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
+}
+",
+                        code.ContextFile);
+
                     Assert.DoesNotContain("namespace ", Assert.Single(code.AdditionalFiles).Code);
                 },
                 model =>