From 1d7ca569164b53d4f20718a84afc160018a01abd Mon Sep 17 00:00:00 2001
From: Mohammadreza Taikandi <mrtaikandi@hotmail.com>
Date: Mon, 8 Feb 2021 07:24:10 +0000
Subject: [PATCH] Add null static analysis attribute.

---
 src/MapTo/Sources/MapClassSource.cs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/MapTo/Sources/MapClassSource.cs b/src/MapTo/Sources/MapClassSource.cs
index 10229b7..5b01509 100644
--- a/src/MapTo/Sources/MapClassSource.cs
+++ b/src/MapTo/Sources/MapClassSource.cs
@@ -43,7 +43,8 @@ namespace MapTo.Sources
         private static SourceBuilder WriteUsings(this SourceBuilder builder, MappingModel model)
         {
             return builder
-                .WriteLine("using System;");
+                .WriteLine("using System;")
+                .WriteLineIf(model.Options.SupportNullableReferenceTypes, "using System.Diagnostics.CodeAnalysis;");
         }
         
         private static SourceBuilder GenerateConstructor(this SourceBuilder builder, MappingModel model)
@@ -94,7 +95,8 @@ namespace MapTo.Sources
 
             return builder
                 .GenerateConvertorMethodsXmlDocs(model, sourceClassParameterName)
-                .WriteLine($"{model.Options.GeneratedMethodsAccessModifier.ToLowercaseString()} static {model.ClassName} From({model.SourceClassFullName}{model.Options.NullableReferenceSyntax} {sourceClassParameterName})")
+                .WriteLineIf(model.Options.SupportNullableReferenceTypes, $"[return: NotNullIfNotNull(\"{sourceClassParameterName}\")]")
+                .WriteLine($"{model.Options.GeneratedMethodsAccessModifier.ToLowercaseString()} static {model.ClassName}{model.Options.NullableReferenceSyntax} From({model.SourceClassFullName}{model.Options.NullableReferenceSyntax} {sourceClassParameterName})")
                 .WriteOpeningBracket()
                 .WriteLine($"return {sourceClassParameterName} == null ? null : new {model.ClassName}({sourceClassParameterName});")
                 .WriteClosingBracket();
@@ -131,7 +133,8 @@ namespace MapTo.Sources
 
             return builder
                 .GenerateConvertorMethodsXmlDocs(model, sourceClassParameterName)
-                .WriteLine($"{model.Options.GeneratedMethodsAccessModifier.ToLowercaseString()} static {model.ClassName} To{model.ClassName}(this {model.SourceClassFullName}{model.Options.NullableReferenceSyntax} {sourceClassParameterName})")
+                .WriteLineIf(model.Options.SupportNullableReferenceTypes, $"[return: NotNullIfNotNull(\"{sourceClassParameterName}\")]")
+                .WriteLine($"{model.Options.GeneratedMethodsAccessModifier.ToLowercaseString()} static {model.ClassName}{model.Options.NullableReferenceSyntax} To{model.ClassName}(this {model.SourceClassFullName}{model.Options.NullableReferenceSyntax} {sourceClassParameterName})")
                 .WriteOpeningBracket()
                 .WriteLine($"return {sourceClassParameterName} == null ? null : new {model.ClassName}({sourceClassParameterName});")
                 .WriteClosingBracket();