From 747871656a906ba2032087bf460377b497fcb50b Mon Sep 17 00:00:00 2001
From: Oleksandr Liakhevych <liakh.oleksandr32@gmail.com>
Date: Sat, 29 Jun 2024 10:39:58 +0300
Subject: [PATCH] Generate matching IServiceProvider parameter name

---
 .../GeneratedMethodTests.cs                   | 40 +++++++++++++++++++
 .../DependencyInjectionGenerator.cs           |  4 +-
 .../Model/MethodModel.cs                      |  4 ++
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/ServiceScan.SourceGenerator.Tests/GeneratedMethodTests.cs b/ServiceScan.SourceGenerator.Tests/GeneratedMethodTests.cs
index 89c8c91..210c6ac 100644
--- a/ServiceScan.SourceGenerator.Tests/GeneratedMethodTests.cs
+++ b/ServiceScan.SourceGenerator.Tests/GeneratedMethodTests.cs
@@ -219,6 +219,46 @@ public static partial IServiceCollection AddServices(this IServiceCollection ser
         Assert.Equal(expected, results.GeneratedTrees[1].ToString());
     }
 
+    [Fact]
+    public void MethodWithCustomParameterName()
+    {
+        var compilation = CreateCompilation(Services,
+            """
+            using ServiceScan.SourceGenerator;
+            using Microsoft.Extensions.DependencyInjection;
+            
+            namespace GeneratorTests;
+                    
+            public static partial class ServicesExtensions
+            {
+                [GenerateServiceRegistrations(AssignableTo = typeof(IService))]
+                public static partial IServiceCollection AddServices(this IServiceCollection strangeServices);
+            }
+            """);
+
+        var results = CSharpGeneratorDriver
+            .Create(_generator)
+            .RunGenerators(compilation)
+            .GetRunResult();
+
+        var expected = """
+            using Microsoft.Extensions.DependencyInjection;
+
+            namespace GeneratorTests;
+
+            public static partial class ServicesExtensions
+            {
+                public static partial IServiceCollection AddServices(this IServiceCollection strangeServices)
+                {
+                    return strangeServices
+                        .AddTransient<GeneratorTests.IService, GeneratorTests.MyService>();
+                }
+            }
+            """;
+
+        Assert.Equal(expected, results.GeneratedTrees[1].ToString());
+    }
+
     private static Compilation CreateCompilation(params string[] source)
     {
         var path = Path.GetDirectoryName(typeof(object).Assembly.Location)!;
diff --git a/ServiceScan.SourceGenerator/DependencyInjectionGenerator.cs b/ServiceScan.SourceGenerator/DependencyInjectionGenerator.cs
index bf67db5..1d5c265 100644
--- a/ServiceScan.SourceGenerator/DependencyInjectionGenerator.cs
+++ b/ServiceScan.SourceGenerator/DependencyInjectionGenerator.cs
@@ -68,9 +68,9 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
                 {{method.TypeModifiers}} class {{method.TypeName}}
                 {
-                    {{method.MethodModifiers}} {{returnType}} {{method.MethodName}}({{(method.IsExtensionMethod ? "this" : "")}} IServiceCollection services)
+                    {{method.MethodModifiers}} {{returnType}} {{method.MethodName}}({{(method.IsExtensionMethod ? "this" : "")}} IServiceCollection {{method.ParameterName}})
                     {
-                        {{(method.ReturnsVoid ? "" : "return ")}}services
+                        {{(method.ReturnsVoid ? "" : "return ")}}{{method.ParameterName}}
                             {{sb.ToString().Trim()}};
                     }
                 }
diff --git a/ServiceScan.SourceGenerator/Model/MethodModel.cs b/ServiceScan.SourceGenerator/Model/MethodModel.cs
index 2c411ec..9c74501 100644
--- a/ServiceScan.SourceGenerator/Model/MethodModel.cs
+++ b/ServiceScan.SourceGenerator/Model/MethodModel.cs
@@ -10,11 +10,14 @@ record MethodModel(
     string TypeModifiers,
     string MethodName,
     string MethodModifiers,
+    string ParameterName,
     bool IsExtensionMethod,
     bool ReturnsVoid)
 {
     public static MethodModel Create(IMethodSymbol method, SyntaxNode syntax)
     {
+        var parameterName = method.Parameters[0].Name;
+
         return new MethodModel(
             Namespace: method.ContainingNamespace.IsGlobalNamespace ? null : method.ContainingNamespace.ToDisplayString(),
             TypeName: method.ContainingType.Name,
@@ -22,6 +25,7 @@ public static MethodModel Create(IMethodSymbol method, SyntaxNode syntax)
             TypeModifiers: GetModifiers(GetTypeSyntax(syntax)),
             MethodName: method.Name,
             MethodModifiers: GetModifiers(syntax),
+            ParameterName: parameterName,
             IsExtensionMethod: method.IsExtensionMethod,
             ReturnsVoid: method.ReturnsVoid);
     }