[CodeAction] IterateViaForeachAction: Add tests for slightly invalid expression statements and use Script.InsertAfter() to avoid problematic formatting.

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/IterateViaForeachAction.cs

@@ -76,14 +76,10 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				return null;
 			return new CodeAction(context.TranslateString("Iterate via foreach"), script => {
 				var iterator = MakeForeach(expression.Clone(), context);
-				if (expression == expressionStatement.Expression) {
+				if (expression == expressionStatement.Expression)
 					script.Replace(expressionStatement, iterator);
-				} else {
-					script.InsertBefore(expressionStatement.NextSibling, iterator);
-					// Work around incorrect formatting when inserting relatively to
-					// a node on a different indentation level
-					script.FormatText(context.GetNode<BlockStatement>());
-				}
+				else
+					script.InsertAfter(expressionStatement, iterator);
 			});
 
 		}

ICSharpCode.NRefactory.Tests/CSharp/CodeActions/IterateViaForeachTests.cs

@@ -124,6 +124,56 @@ class TestClass
 }");
 		}
 
+		[Test]
+		public void HandlesAsExpressionStatement()
+		{
+			Test<IterateViaForeachAction>(@"
+using System.Collections.Generic;
+class TestClass
+{
+	public void F()
+	{
+		object s = """";
+		s as IEnumerable$<char>;
+	}
+}", @"
+using System.Collections.Generic;
+class TestClass
+{
+	public void F()
+	{
+		object s = """";
+		foreach (var item in s as IEnumerable<char>) {
+		}
+	}
+}", 0, true);
+		}
+
+		[Test]
+		public void HandlesAsExpression()
+		{
+			Test<IterateViaForeachAction>(@"
+using System.Collections.Generic;
+class TestClass
+{
+	public void F()
+	{
+		object s = """";
+		s as IEnumerable$<char>
+	}
+}", @"
+using System.Collections.Generic;
+class TestClass
+{
+	public void F()
+	{
+		object s = """";
+		foreach (var item in s as IEnumerable<char>) {
+		}
+	}
+}", 0, true);
+		}
+
 		[Test]
 		public void HandlesLinqExpressionAssignment()
 		{