Add explicit support for OpenAPI configuration files

README.md

@@ -55,6 +55,10 @@ A collection of Visual Studio C# custom tool code generators for Swagger / OpenA
   - `.refitter` settings files from [Refitter](https://github.com/christianhelle/refitter) by including it in the project and using the **Generate Refitter output** context menu
   - `kiota-lock.json` configuration files from [Microsoft Kiota](https://github.com/microsoft/kiota) by including it in the project and using the **Generate Kiota output** context menu
 
+### OpenAPI Generator configuration files
+
+For the `rapicgen csharp openapi` command, you can now pass `--config-file <path>` to use a specific OpenAPI Generator configuration file. When no explicit file is supplied, Rapicgen also auto-discovers adjacent files named `<spec>.config.<ext>`, `<spec>.config.json`, and `<spec>.config.yaml` when `--use-configuration-file` is enabled. This makes it easier to drive package name, output layout, project format, and similar OpenAPI Generator options from configuration rather than relying only on the defaults.
+
 ### Custom Tools
 
 Custom tools let you associate a tool with an item in a project and run that tool whenever the file is saved

src/CLI/ApiClientCodeGen.CLI/Commands/CSharp/OpenApiCSharpGeneratorCommand.cs

@@ -57,6 +57,10 @@ public class OpenApiCSharpGeneratorCommandSettings :
         [Description("Path to directory containing additional mustache template files")]
         public string? TemplatesPath { get; set; }
 
+        [CommandOption("--config-file")]
+        [Description("Path to an OpenAPI Generator configuration file to use instead of auto-discovery")]
+        public string? ConfigurationFile { get; set; }
+
         [CommandOption("--use-configuration-file")]
         [Description("Use the configuration file if present")]
         public bool UseConfigurationFile { get; set; } = true;

src/Core/ApiClientCodeGen.Core.Tests/Generators/OpenApi/OpenApiCSharpCodeGeneratorTests.cs

@@ -1,9 +1,17 @@
-using ApiClientCodeGen.Tests.Common;
+using System;
+using System.IO;
+using ApiClientCodeGen.Tests.Common;
 using ApiClientCodeGen.Tests.Common.Infrastructure;
 using AutoFixture.Xunit2;
+using Moq;
 using Rapicgen.Core;
+using Rapicgen.Core.External;
+using Rapicgen.Core.Generators;
 using Rapicgen.Core.Generators.OpenApi;
-using Moq;
+using Rapicgen.Core.Installer;
+using Rapicgen.Core.Options.General;
+using Rapicgen.Core.Options.OpenApiGenerator;
+using Rapicgen.Core.Extensions;
 using Xunit;
 
 namespace ApiClientCodeGen.Core.Tests.Generators.OpenApi
@@ -23,5 +31,60 @@ public void Updates_Progress(
                         It.IsAny<uint>()),
                     Times.Exactly(5));
         }
+
+        [Fact]
+        public void GenerateCode_Uses_Explicit_Configuration_File_When_Specified()
+        {
+            var tempDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(tempDirectory);
+
+            try
+            {
+                var swaggerFile = Path.Combine(tempDirectory, "petstore.yaml");
+                File.WriteAllText(swaggerFile, "openapi: 3.0.0");
+
+                var configFile = Path.Combine(tempDirectory, "petstore.config.yaml");
+                File.WriteAllText(configFile, "generatorName: csharp");
+
+                var version = OpenApiSupportedVersion.V7230;
+                var jarFile = Path.Combine(Path.GetTempPath(), $"openapi-generator-cli-{version.GetDescription()}.jar");
+                File.WriteAllText(jarFile, "jar");
+
+                var processLauncher = new Mock<IProcessLauncher>();
+                var dependencyInstaller = new Mock<IDependencyInstaller>();
+                var options = new DefaultGeneralOptions();
+                var openApiGeneratorOptions = new DefaultOpenApiGeneratorOptions
+                {
+                    Version = version,
+                    ConfigurationFile = configFile,
+                    UseConfigurationFile = false
+                };
+
+                var sut = new OpenApiCSharpCodeGenerator(
+                    swaggerFile,
+                    "GeneratedCode",
+                    options,
+                    openApiGeneratorOptions,
+                    processLauncher.Object,
+                    dependencyInstaller.Object);
+
+                sut.GenerateCode(null);
+
+                processLauncher.Verify(
+                    p => p.Start(
+                        It.IsAny<string>(),
+                        It.Is<string>(arguments => arguments.Contains($"-c \"{configFile}\"")),
+                        It.IsAny<string?>()),
+                    Times.Once);
+            }
+            finally
+            {
+                Directory.Delete(tempDirectory, recursive: true);
+                if (File.Exists(Path.Combine(Path.GetTempPath(), $"openapi-generator-cli-{OpenApiSupportedVersion.V7230.GetDescription()}.jar")))
+                {
+                    File.Delete(Path.Combine(Path.GetTempPath(), $"openapi-generator-cli-{OpenApiSupportedVersion.V7230.GetDescription()}.jar"));
+                }
+            }
+        }
     }
 }

src/Core/ApiClientCodeGen.Core/Generators/OpenApi/OpenApiCSharpCodeGenerator.cs

@@ -76,7 +76,18 @@ public string GenerateCode(IProgressReporter? pGenerateProgress)
                     arguments += $"--http-user-agent \"{openApiGeneratorOptions.HttpUserAgent}\" ";
                 }
 
-                if (openApiGeneratorOptions.UseConfigurationFile)
+                if (!string.IsNullOrWhiteSpace(openApiGeneratorOptions.ConfigurationFile))
+                {
+                    var configFile = openApiGeneratorOptions.ConfigurationFile;
+                    if (!Path.IsPathRooted(configFile))
+                    {
+                        var swaggerDirectory = Path.GetDirectoryName(swaggerFile) ?? Directory.GetCurrentDirectory();
+                        configFile = Path.GetFullPath(Path.Combine(swaggerDirectory, configFile));
+                    }
+
+                    arguments += $"-c \"{configFile}\" ";
+                }
+                else if (openApiGeneratorOptions.UseConfigurationFile)
                 {
                     var extension = Path.GetExtension(swaggerFile);
                     if (extension != null)

src/Core/ApiClientCodeGen.Core/Options/OpenApiGenerator/DefaultOpenApiGeneratorOptions.cs

@@ -23,6 +23,8 @@ public class DefaultOpenApiGeneratorOptions : IOpenApiGeneratorOptions
 
         public string? TemplatesPath { get; set; }
 
+        public string? ConfigurationFile { get; set; }
+
         public bool UseConfigurationFile { get; set; } = false;
 
         public bool GenerateMultipleFiles { get; set; }

src/Core/ApiClientCodeGen.Core/Options/OpenApiGenerator/IOpenApiGeneratorOptions.cs

@@ -11,6 +11,7 @@ public interface IOpenApiGeneratorOptions
         string? CustomAdditionalProperties { get; set; }
         bool SkipFormModel { get; set; }
         string? TemplatesPath { get; set; }
+        string? ConfigurationFile { get; set; }
         bool UseConfigurationFile { get; set; }
         bool GenerateMultipleFiles { get; set; }
         public OpenApiSupportedVersion Version { get; set; }

src/VSIX/ApiClientCodeGen.VSIX.Extensibility/Settings/ExtensionSettingsProvider.cs

@@ -220,6 +220,7 @@ private sealed class OpenApiOptions(SettingValues values) : IOpenApiGeneratorOpt
             = NormalizeEmpty(values.ValueOrDefault(OpenApiGeneratorSettings.OpenApiCustomAdditionalProperties, string.Empty));
         public bool SkipFormModel { get; set; } = values.ValueOrDefault(OpenApiGeneratorSettings.OpenApiSkipFormModel, true);
         public string? TemplatesPath { get; set; } = NormalizeEmpty(values.ValueOrDefault(OpenApiGeneratorSettings.OpenApiTemplatesPath, string.Empty));
+        public string? ConfigurationFile { get; set; }
         public bool UseConfigurationFile { get; set; } = values.ValueOrDefault(OpenApiGeneratorSettings.OpenApiUseConfigurationFile, true);
         public bool GenerateMultipleFiles { get; set; } = values.ValueOrDefault(OpenApiGeneratorSettings.OpenApiGenerateMultipleFiles, false);
         public OpenApiSupportedVersion Version { get; set; }

src/VSIX/ApiClientCodeGen.VSIX.Shared/Options/OpenApiGenerator/OpenApiGeneratorOptionsPage.cs

@@ -60,6 +60,11 @@ public class OpenApiGeneratorOptionsPage : DialogPage, IOpenApiGeneratorOptions
                      "This should be either an absolute path or a path relative to the swagger file.")]
         public string? TemplatesPath { get; set; } = null!;
 
+        [Category(Name)]
+        [DisplayName("Configuration File")]
+        [Description("Optional path to an OpenAPI Generator configuration file. When set, the generator uses this file instead of auto-discovering one next to the swagger file.")]
+        public string? ConfigurationFile { get; set; } = null!;
+
         [Category(Name)]
         [DisplayName("Use Configuration File")]
         [Description("Use the configuration file if present.")]