From 8f7528a8b60fc7ffc3a3378e46ba48d88f54ab9b Mon Sep 17 00:00:00 2001
From: Tim M <49349513+TimothyMakkison@users.noreply.github.com>
Date: Wed, 20 Sep 2023 07:11:16 +0100
Subject: [PATCH] fix: escape method parameters with reserved keywords (#756)

---
 src/Riok.Mapperly/Symbols/MethodParameter.cs   | 8 +++++++-
 test/Riok.Mapperly.Tests/Mapping/MapperTest.cs | 7 +++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/Riok.Mapperly/Symbols/MethodParameter.cs b/src/Riok.Mapperly/Symbols/MethodParameter.cs
index 6f828d030e..4bc9a60227 100644
--- a/src/Riok.Mapperly/Symbols/MethodParameter.cs
+++ b/src/Riok.Mapperly/Symbols/MethodParameter.cs
@@ -6,8 +6,14 @@ namespace Riok.Mapperly.Symbols;
 
 public readonly record struct MethodParameter(int Ordinal, string Name, ITypeSymbol Type)
 {
+    private static readonly SymbolDisplayFormat _parameterNameFormat =
+        new(
+            parameterOptions: SymbolDisplayParameterOptions.IncludeName,
+            miscellaneousOptions: SymbolDisplayMiscellaneousOptions.EscapeKeywordIdentifiers
+        );
+
     public MethodParameter(IParameterSymbol symbol)
-        : this(symbol.Ordinal, symbol.Name, symbol.Type.UpgradeNullable()) { }
+        : this(symbol.Ordinal, symbol.ToDisplayString(_parameterNameFormat), symbol.Type.UpgradeNullable()) { }
 
     public MethodArgument WithArgument(ExpressionSyntax? argument) =>
         new(this, argument ?? throw new ArgumentNullException(nameof(argument)));
diff --git a/test/Riok.Mapperly.Tests/Mapping/MapperTest.cs b/test/Riok.Mapperly.Tests/Mapping/MapperTest.cs
index 511be80714..73a05b45a1 100644
--- a/test/Riok.Mapperly.Tests/Mapping/MapperTest.cs
+++ b/test/Riok.Mapperly.Tests/Mapping/MapperTest.cs
@@ -147,4 +147,11 @@ enum E2 { Value1 }
 
         return TestHelper.VerifyGenerator(source);
     }
+
+    [Fact]
+    public void RestrictedKeywordParametersShouldBeEscaped()
+    {
+        var source = TestSourceBuilder.MapperWithBody("public partial string Map(int @object);");
+        TestHelper.GenerateMapper(source).Should().HaveSingleMethodBody("return @object.ToString();");
+    }
 }