style: move using directive to top

.editorconfig

@@ -91,6 +91,7 @@ csharp_prefer_braces = when_multiline:warning
 csharp_prefer_simple_using_statement = true:warning
 
 csharp_using_directive_placement = outside_namespace
+csharp_style_namespace_declarations = file_scoped
 
 csharp_prefer_static_local_function = true:warning
 

sandbox/Benchmark/BenchmarkConfig.cs

@@ -1,9 +1,9 @@
-namespace Benchmark;
-
 using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Environments;
 using BenchmarkDotNet.Jobs;
 
+namespace Benchmark;
+
 public class BenchmarkConfig : ManualConfig
 {
     public BenchmarkConfig()

sandbox/Benchmark/WritableOptionsBenchmark.cs

@@ -1,9 +1,8 @@
 #nullable disable
-namespace Benchmark;
-
-using System.IO;
 using BenchmarkDotNet.Attributes;
 
+namespace Benchmark;
+
 [Config(typeof(BenchmarkConfig))]
 public class WritableOptionsBenchmark
 {

src/Nogic.WritableOptions/IWritableOptions.cs

@@ -1,7 +1,7 @@
-namespace Nogic.WritableOptions;
-
 using Microsoft.Extensions.Options;
 
+namespace Nogic.WritableOptions;
+
 /// <summary>
 /// Used to access or update the value of <typeparamref name="TOptions"/>.
 /// </summary>

src/Nogic.WritableOptions/JsonWritableOptions.cs

@@ -1,12 +1,11 @@
-namespace Nogic.WritableOptions;
-
-using System.IO;
 using System.Text;
 using System.Text.Encodings.Web;
 using System.Text.Json;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Options;
 
+namespace Nogic.WritableOptions;
+
 /// <summary>
 /// Read and write <typeparamref name="TOptions"/> in JSON file.
 /// </summary>

src/Nogic.WritableOptions/ServiceCollectionExtension.cs

@@ -1,11 +1,10 @@
-namespace Nogic.WritableOptions;
-
-using System.IO;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Options;
 
+namespace Nogic.WritableOptions;
+
 /// <summary>
 /// Extension methods for adding configuration related writable options services to the DI container.
 /// </summary>

test/Nogic.WritableOptions.Tests/JsonWritableOptions.Test.cs

@@ -1,11 +1,10 @@
-namespace Nogic.WritableOptions.Tests;
-
-using System.IO;
 using System.Text;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Options;
 using Moq;
 
+namespace Nogic.WritableOptions.Tests;
+
 /// <summary>
 /// Unit Test Class for <see cref="JsonWritableOptions{TOptions}"/>.
 /// </summary>

test/Nogic.WritableOptions.Tests/ServiceCollectionExtension.Test.cs

@@ -1,8 +1,8 @@
-namespace Nogic.WritableOptions.Tests;
-
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
+namespace Nogic.WritableOptions.Tests;
+
 /// <summary>
 /// Unit Test Class for <see cref="ServiceCollectionExtension"/>.
 /// </summary>