From d36234625f39d6c47d41e23a6c520ca794ae2040 Mon Sep 17 00:00:00 2001
From: Tanner Gooding <tagoo@outlook.com>
Date: Sun, 12 Jul 2026 16:20:57 -0700
Subject: [PATCH] Standardize argument-name validation in OutputBuilderFactory

The five public methods each duplicated the same `string name` guard,
split across two styles: an `if (string.IsNullOrWhiteSpace(name)) throw`
block in `Create`/`CreateTests` and a ternary-throw form in
`GetOutputBuilder`/`GetTestOutputBuilder`/`TryGetOutputBuilder`. Factor
the check into a single private `ValidateName` helper and call it from
every method so the guard lives in one place.

Preserve exception semantics exactly. The existing guard throws
`ArgumentNullException(nameof(name))` for null, empty, and whitespace
names, so `ValidateName` retains the `string.IsNullOrWhiteSpace` check
rather than switching to `ArgumentNullException.ThrowIfNull` (which
would not throw for non-null empty/whitespace) or
`ArgumentException.ThrowIfNullOrWhiteSpace` (which would throw
`ArgumentException` instead). The distinct `ArgumentException` for a
non-test builder in `GetTestOutputBuilder` is left unchanged.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
---
 .../OutputBuilderFactory.cs                   | 34 +++++++++++--------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/sources/ClangSharp.PInvokeGenerator/OutputBuilderFactory.cs b/sources/ClangSharp.PInvokeGenerator/OutputBuilderFactory.cs
index de4693e7..b7621d38 100644
--- a/sources/ClangSharp.PInvokeGenerator/OutputBuilderFactory.cs
+++ b/sources/ClangSharp.PInvokeGenerator/OutputBuilderFactory.cs
@@ -20,10 +20,7 @@ internal sealed class OutputBuilderFactory(PInvokeGenerator generator)
 
     public IOutputBuilder Create(string name)
     {
-        if (string.IsNullOrWhiteSpace(name))
-        {
-            throw new ArgumentNullException(nameof(name));
-        }
+        ValidateName(name);
 
         var outputBuilder = generator.Config.OutputMode switch
         {
@@ -38,10 +35,7 @@ public IOutputBuilder Create(string name)
 
     public CSharpOutputBuilder CreateTests(string name)
     {
-        if (string.IsNullOrWhiteSpace(name))
-        {
-            throw new ArgumentNullException(nameof(name));
-        }
+        ValidateName(name);
 
         var outputBuilder = new CSharpOutputBuilder(name, generator, isTestOutput: true, writeSourceLocation: _writeSourceLocation);
 
@@ -49,21 +43,31 @@ public CSharpOutputBuilder CreateTests(string name)
         return outputBuilder;
     }
 
-    public IOutputBuilder GetOutputBuilder(string name) => string.IsNullOrWhiteSpace(name) ? throw new ArgumentNullException(nameof(name)) : _outputBuilders[name];
+    public IOutputBuilder GetOutputBuilder(string name)
+    {
+        ValidateName(name);
+        return _outputBuilders[name];
+    }
 
     public CSharpOutputBuilder GetTestOutputBuilder(string name)
     {
-        return string.IsNullOrWhiteSpace(name)
-            ? throw new ArgumentNullException(nameof(name))
-            : _outputBuilders[name] is CSharpOutputBuilder csharpOutputBuilder && csharpOutputBuilder.IsTestOutput
+        ValidateName(name);
+        return _outputBuilders[name] is CSharpOutputBuilder csharpOutputBuilder && csharpOutputBuilder.IsTestOutput
             ? csharpOutputBuilder
             : throw new ArgumentException("A test output builder was not found with the given name", nameof(name));
     }
 
     public bool TryGetOutputBuilder(string name, [MaybeNullWhen(false)] out IOutputBuilder outputBuilder)
     {
-        return string.IsNullOrWhiteSpace(name)
-            ? throw new ArgumentNullException(nameof(name))
-            : _outputBuilders.TryGetValue(name, out outputBuilder);
+        ValidateName(name);
+        return _outputBuilders.TryGetValue(name, out outputBuilder);
+    }
+
+    private static void ValidateName([NotNull] string name)
+    {
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            throw new ArgumentNullException(nameof(name));
+        }
     }
 }