Add support for generating multiple files per Refit interface

src/Refitter.Core/FilenameConstants.cs

@@ -1,8 +1,8 @@
 namespace Refitter.Core;
 
-public static class FilenameConstants
+public static class TypenameConstants
 {
-    public const string RefitInterfaces = "RefitInterfaces.cs";
-    public const string Contracts = "Contracts.cs";
-    public const string DependencyInjection = "DependencyInjection.cs";
+    public const string RefitInterfaces = "RefitInterfaces";
+    public const string Contracts = "Contracts";
+    public const string DependencyInjection = "DependencyInjection";
 }

src/Refitter.Core/GeneratedCode.cs

@@ -3,4 +3,7 @@
 namespace Refitter.Core;
 
 [ExcludeFromCodeCoverage]
-public record GeneratedCode(string Filename, string Content);
+public record GeneratedCode(string TypeName, string Content)
+{
+    public string Filename { get; } = $"{TypeName}.cs";
+}

src/Refitter.Core/IRefitInterfaceGenerator.cs

@@ -2,5 +2,5 @@ namespace Refitter.Core;
 
 internal interface IRefitInterfaceGenerator
 {
-    RefitGeneratedCode GenerateCode();
-}
+    IEnumerable<GeneratedCode> GenerateCode();
+}

src/Refitter.Core/RefitGenerator.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 using System.Text.RegularExpressions;
 using NSwag;
 
@@ -141,17 +141,20 @@ public string Generate()
             _ => new RefitInterfaceGenerator(settings, document, generator, docGenerator),
         };
 
-        var generatedCode = GenerateClient(interfaceGenerator);
+        var refitInterfaces = GenerateClient(interfaceGenerator);
+        var interfaceNames = refitInterfaces.Select(c => c.TypeName).ToArray();
+        var refitInterfacesCode = string.Join("", refitInterfaces.Select(c => c.Content));
         var title = settings.Naming.UseOpenApiTitle && !string.IsNullOrWhiteSpace(document.Info?.Title)
             ? document.Info!.Title.Sanitize()
             : settings.Naming.InterfaceName;
         return new StringBuilder()
-            .AppendLine(settings.GenerateClients ? generatedCode.SourceCode : string.Empty)
+            .AppendLine(settings.GenerateClients ? refitInterfacesCode : string.Empty)
             .AppendLine()
             .AppendLine(settings.GenerateContracts ? contracts : string.Empty)
-            .AppendLine(settings.ApizrSettings != null
-                ? ApizrRegistrationGenerator.Generate(settings, generatedCode.InterfaceNames, title)
-                : DependencyInjectionGenerator.Generate(settings, generatedCode.InterfaceNames))
+            .AppendLine(
+                settings.ApizrSettings != null
+                    ? ApizrRegistrationGenerator.Generate(settings, interfaceNames, title)
+                    : DependencyInjectionGenerator.Generate(settings, interfaceNames))
             .ToString()
             .TrimEnd();
     }
@@ -174,12 +177,15 @@ public GeneratorOutput GenerateMultipleFiles()
 
         var generatedFiles = new List<GeneratedCode>();
 
-        var interfaces = GenerateClient(interfaceGenerator);
-        generatedFiles.Add(new GeneratedCode(FilenameConstants.RefitInterfaces, interfaces.SourceCode));
+        var refitInterfaces = GenerateClient(interfaceGenerator);
+        generatedFiles.AddRange(refitInterfaces);
 
         if (settings.GenerateContracts)
         {
-            generatedFiles.Add(new GeneratedCode(FilenameConstants.Contracts, contracts));
+            generatedFiles.Add(
+                new GeneratedCode(
+                    TypenameConstants.Contracts,
+                    contracts));
         }
 
         if (settings.DependencyInjectionSettings is not null || settings.ApizrSettings is not null)
@@ -188,13 +194,17 @@ public GeneratorOutput GenerateMultipleFiles()
                 ? document.Info!.Title.Sanitize()
                 : settings.Naming.InterfaceName;
 
+            var interfaceNames = refitInterfaces.Select(c => c.TypeName).ToArray();
             var configurationCode = settings.ApizrSettings != null
-                ? ApizrRegistrationGenerator.Generate(settings, interfaces.InterfaceNames, title)
-                : DependencyInjectionGenerator.Generate(settings, interfaces.InterfaceNames);
+                ? ApizrRegistrationGenerator.Generate(settings, interfaceNames, title)
+                : DependencyInjectionGenerator.Generate(settings, interfaceNames);
 
             if (!string.IsNullOrWhiteSpace(configurationCode))
             {
-                generatedFiles.Add(new GeneratedCode(FilenameConstants.DependencyInjection, configurationCode));
+                generatedFiles.Add(
+                    new GeneratedCode(
+                        TypenameConstants.DependencyInjection,
+                        configurationCode));
             }
         }
 
@@ -206,7 +216,7 @@ public GeneratorOutput GenerateMultipleFiles()
     /// </summary>
     /// <param name="interfaceGenerator">The interface generator used to generate the client code.</param>
     /// <returns>The generated client code as a string.</returns>
-    private RefitGeneratedCode GenerateClient(IRefitInterfaceGenerator interfaceGenerator)
+    private IReadOnlyCollection<GeneratedCode> GenerateClient(IRefitInterfaceGenerator interfaceGenerator)
     {
         var code = new StringBuilder();
         GenerateAutoGeneratedHeader(code);
@@ -229,14 +239,42 @@ private RefitGeneratedCode GenerateClient(IRefitInterfaceGenerator interfaceGene
         code.AppendLine();
 
         var refitInterfaces = interfaceGenerator.GenerateCode();
-        code.AppendLine($$"""
-                          namespace {{settings.Namespace}}
-                          {
-                          {{refitInterfaces}}
-                          }
-                          """);
-
-        return new RefitGeneratedCode(code.ToString(), refitInterfaces.InterfaceNames);
+        var generatedCodes = refitInterfaces as GeneratedCode[] ?? refitInterfaces.ToArray();
+
+        if (settings.GenerateMultipleFiles)
+        {
+            for (int i = 0; i < generatedCodes.Length; i++)
+            {
+                generatedCodes[i] = generatedCodes[i] with
+                {
+                    Content = code +
+                              $$"""
+                                namespace {{settings.Namespace}}
+                                {
+                                {{generatedCodes[i].Content}}
+                                }
+                                """
+                };
+            }
+            return generatedCodes;
+        }
+
+        code.AppendLine($"namespace {settings.Namespace}");
+        code.AppendLine("{");
+
+        foreach (var generatedCode in generatedCodes)
+        {
+            code.AppendLine(generatedCode.Content);
+        }
+
+        code.Append("}");
+
+        return new[] { new GeneratedCode(generatedCodes.First().TypeName, code.ToString()) }
+            .Union(
+                generatedCodes
+                    .Skip(1)
+                    .Select(c => new GeneratedCode(c.TypeName, string.Empty)))
+            .ToArray();
     }
 
     /// <summary>

src/Refitter.Core/RefitInterfaceGenerator.cs

@@ -27,17 +27,18 @@ internal RefitInterfaceGenerator(
         generator.BaseSettings.OperationNameGenerator = new OperationNameGenerator(document, settings);
     }
 
-    public virtual RefitGeneratedCode GenerateCode()
+    public virtual IEnumerable<GeneratedCode> GenerateCode()
     {
-        return new RefitGeneratedCode(
+        var interfaceDeclaration = GenerateInterfaceDeclaration(out var interfaceName);
+        yield return new GeneratedCode(
+            interfaceName,
             $$"""
-              {{GenerateInterfaceDeclaration(out var interfaceName)}}
+              {{interfaceDeclaration}}
               {{Separator}}{
               {{GenerateInterfaceBody(out var dynamicQuerystringParameters)}}
               {{Separator}}}
               {{dynamicQuerystringParameters}}
-              """,
-            interfaceName);
+              """);
     }
 
     private string GenerateInterfaceBody(out string? dynamicQuerystringParameters)

src/Refitter.Core/RefitMultipleInterfaceByTagGenerator.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 using NSwag;
 
 namespace Refitter.Core;
@@ -16,7 +16,7 @@ internal RefitMultipleInterfaceByTagGenerator(
     {
     }
 
-    public override RefitGeneratedCode GenerateCode()
+    public override IEnumerable<GeneratedCode> GenerateCode()
     {
         var ungroupedTitle = settings.Naming.UseOpenApiTitle
             ? IdentifierUtils.Sanitize(document.Info?.Title ?? "ApiClient")
@@ -28,8 +28,7 @@ public override RefitGeneratedCode GenerateCode()
             .GroupBy(x => GetGroupName(x.Operation.Value, ungroupedTitle), (k, v) => new { Key = k, Combined = v });
 
         Dictionary<string, StringBuilder> interfacesByGroup = new();
-        var interfaceNames = new List<string>();
-        var dynamicQuerystringParametersCodeBuilder = new StringBuilder();
+        Dictionary<string, string> interfacesNamesByGroup = new();
 
         foreach (var kv in byGroup)
         {
@@ -53,21 +52,31 @@ public override RefitGeneratedCode GenerateCode()
                     this.docGenerator.AppendInterfaceDocumentation(operation, sb);
 
                     interfaceName = GetInterfaceName(kv.Key);
-                    interfaceNames.Add(interfaceName);
                     sb.AppendLine($$"""
                                     {{GenerateInterfaceDeclaration(interfaceName)}}
                                     {{Separator}}{
                                     """);
+
+                    interfacesNamesByGroup[kv.Key] = interfaceName;
                 }
 
                 var operationName = GetOperationName(interfaceName, op.PathItem.Key, operations.Key, operation);
                 var dynamicQuerystringParameterType = operationName + "QueryParams";
                 var operationModel = generator.CreateOperationModel(operation);
-                var parameters = ParameterExtractor.GetParameters(operationModel, operation, settings, dynamicQuerystringParameterType, out var operationDynamicQuerystringParameters).ToList();
+                var parameters = ParameterExtractor
+                    .GetParameters(
+                        operationModel,
+                        operation,
+                        settings,
+                        dynamicQuerystringParameterType,
+                        out var operationDynamicQuerystringParameters)
+                    .ToList();
 
                 var hasDynamicQuerystringParameter = !string.IsNullOrWhiteSpace(operationDynamicQuerystringParameters);
                 if (hasDynamicQuerystringParameter)
-                    dynamicQuerystringParametersCodeBuilder.AppendLine(operationDynamicQuerystringParameters);
+                    yield return new GeneratedCode(
+                        dynamicQuerystringParameterType,
+                        operationDynamicQuerystringParameters!);
 
                 var parametersString = string.Join(", ", parameters);
                 var hasApizrRequestOptionsParameter = settings.ApizrSettings?.WithRequestOptions == true;
@@ -97,23 +106,24 @@ public override RefitGeneratedCode GenerateCode()
             }
         }
 
-        var code = new StringBuilder();
-        foreach (var value in interfacesByGroup.Select(kv => kv.Value))
+        foreach (var keyValuePair in interfacesByGroup)
         {
+            var code = new StringBuilder();
+            var key = keyValuePair.Key;
+            var value = keyValuePair.Value;
+
             while (char.IsWhiteSpace(value[value.Length - 1]))
             {
                 value.Length--;
             }
 
             code.AppendLine(value.ToString());
             code.AppendLine($"{Separator}}}");
-            code.AppendLine();
-        }
 
-        if (dynamicQuerystringParametersCodeBuilder.Length > 0) 
-            code.AppendLine(dynamicQuerystringParametersCodeBuilder.ToString());
-
-        return new RefitGeneratedCode(code.ToString(), interfaceNames.ToArray());
+            yield return new GeneratedCode(
+                interfacesNamesByGroup[key],
+                code.ToString());
+        }
     }
 
     private string GetGroupName(OpenApiOperation operation, string ungroupedTitle)
@@ -158,4 +168,4 @@ private string GenerateInterfaceDeclaration(string name)
                 {Separator}{modifier} partial interface {name}
                 """;
     }
-}
+}

src/Refitter.Core/RefitMultipleInterfaceGenerator.cs

@@ -16,12 +16,8 @@ internal RefitMultipleInterfaceGenerator(
     {
     }
 
-    public override RefitGeneratedCode GenerateCode()
+    public override IEnumerable<GeneratedCode> GenerateCode()
     {
-        var code = new StringBuilder();
-        var interfaceNames = new List<string>();
-        var dynamicQuerystringParametersCodeBuilder = new StringBuilder();
-
         foreach (var kv in document.Paths)
         {
             foreach (var operations in kv.Value)
@@ -36,11 +32,11 @@ public override RefitGeneratedCode GenerateCode()
                 var returnType = GetTypeName(operation);
                 var verb = operations.Key.CapitalizeFirstCharacter();
                 var methodName = settings.OperationNameTemplate ?? "Execute";
+                var code = new StringBuilder();
 
                 this.docGenerator.AppendInterfaceDocumentation(operation, code);
-                
+
                 var interfaceName = GetInterfaceName(kv, verb, operation);
-                interfaceNames.Add(interfaceName);
                 code.AppendLine($$"""
                                   {{GenerateInterfaceDeclaration(interfaceName)}}
                                   {{Separator}}{
@@ -52,7 +48,9 @@ public override RefitGeneratedCode GenerateCode()
 
                 var hasDynamicQuerystringParameter = !string.IsNullOrWhiteSpace(methodDynamicQuerystringParameters);
                 if (hasDynamicQuerystringParameter)
-                    dynamicQuerystringParametersCodeBuilder.AppendLine(methodDynamicQuerystringParameters);
+                    yield return new GeneratedCode(
+                        dynamicQuerystringParameterType,
+                        methodDynamicQuerystringParameters!);
 
                 var parametersString = string.Join(", ", parameters);
                 var hasApizrRequestOptionsParameter = settings.ApizrSettings?.WithRequestOptions == true;
@@ -64,8 +62,7 @@ public override RefitGeneratedCode GenerateCode()
 
                 code.AppendLine($"{Separator}{Separator}[{verb}(\"{kv.Key}\")]")
                     .AppendLine($"{Separator}{Separator}{returnType} {methodName}({parametersString});")
-                    .AppendLine($"{Separator}}}")
-                    .AppendLine();
+                    .AppendLine($"{Separator}}}");
 
                 if (parametersString.Contains("?") && settings is { OptionalParameters: true, ApizrSettings: not null })
                 {
@@ -80,13 +77,10 @@ public override RefitGeneratedCode GenerateCode()
                         .AppendLine($"{Separator}{Separator}{returnType} {methodName}({parametersString});")
                         .AppendLine();
                 }
+
+                yield return new GeneratedCode(interfaceName, code.ToString());
             }
         }
-
-        if (dynamicQuerystringParametersCodeBuilder.Length > 0) 
-            code.AppendLine(dynamicQuerystringParametersCodeBuilder.ToString());
-
-        return new RefitGeneratedCode(code.ToString(), interfaceNames.ToArray());
     }
 
     private string GetInterfaceName(
@@ -113,4 +107,4 @@ private string GenerateInterfaceDeclaration(string name)
                 {Separator}{modifier} partial interface {name}
                 """;
     }
-}
+}

src/Refitter.Core/Refitter.Core.csproj

@@ -15,6 +15,7 @@
     <PackageReference Include="NSwag.CodeGeneration.CSharp" Version="14.1.0" />
     <PackageReference Include="NSwag.Core.Yaml" Version="14.1.0" />
     <PackageReference Include="OasReader" Version="1.6.16.15" />
+    <PackageReference Include="System.Text.Json" Version="8.0.4" />
   </ItemGroup>
 
   <ItemGroup>

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/Refitter.g.cs

@@ -375,7 +375,6 @@ public partial interface ISwaggerPetstore
 
 }
 
-
 //----------------------
 // <auto-generated>
 //     Generated using the NSwag toolchain v14.1.0.0 (NJsonSchema v11.0.2.0 (Newtonsoft.Json v13.0.0.0)) (http://NSwag.org)

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/SwaggerPetstoreMultipleInterfaces.g.cs

@@ -451,13 +451,11 @@ public partial interface IDeleteUserEndpoint
         Task Execute(string username);
     }
 
-
 }
 
 
 
 
-
 #nullable enable
 namespace Refitter.Tests.AdditionalFiles.ByEndpoint
 {

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/SwaggerPetstoreMultipleInterfacesByTag.g.cs

@@ -371,5 +371,4 @@ public partial interface IUserApi
         Task DeleteUser(string username);
     }
 
-
 }