fix to validate option argument

Author: smdn

src/Smdn.Reflection.ReverseGenerating/Smdn.Reflection.ReverseGenerating/Generator.Attributes.cs

@@ -39,6 +39,8 @@ GeneratorOptions options
   {
     if (attributeProvider is null)
       throw new ArgumentNullException(nameof(attributeProvider));
+    if (options is null)
+      throw new ArgumentNullException(nameof(options));
 
     const string attributeSectionPrefixDefault = "[";
     const string attributeSectionPrefixField = "[field: ";

tests/Smdn.Reflection.ReverseGenerating/Smdn.Reflection.ReverseGenerating/Generator.cs

@@ -248,4 +248,12 @@ public void GenerateExplicitBaseTypeAndInterfaces_ArgumentOptionsNull()
   [Test]
   public void GenerateExplicitBaseTypeAndInterfaces_ArgumentTypeNull()
     => Assert.Throws<ArgumentNullException>(() => Generator.GenerateExplicitBaseTypeAndInterfaces(t: null!, null, options: new()));
+
+  [Test]
+  public void GenerateAttributeList_ArgumentOptionsNull()
+    => Assert.Throws<ArgumentNullException>(() => Generator.GenerateAttributeList(attributeProvider: typeof(int), null, options: null!));
+
+  [Test]
+  public void GenerateAttributeList_ArgumentAttributeProviderNull()
+    => Assert.Throws<ArgumentNullException>(() => Generator.GenerateAttributeList(attributeProvider: null!, null, options: new()));
 }