Maintaining surrounding parentheses of multi-parameter lambda method arguments

Author: SteveWilkes

ReadableExpressions.UnitTests/WhenFormattingCode.cs

@@ -506,6 +506,18 @@ public void ShouldNotRemoveParenthesesFromACastObjectChainedMethodCall()
             Assert.AreEqual("strings = ((int[])ints).ToString().Split(',')", translated);
         }
 
+        [TestMethod]
+        public void ShouldNotRemoveParenthesesFromMultiParameterLambdaArguments()
+        {
+            Expression<Func<IEnumerable<string>, string[]>> stringsConverter =
+                strings => strings.Select((str, i) => string.Join(i + ": ", str)).ToArray();
+
+            const string EXPECTED = "strings.Select((str, i) => string.Join(i + \": \", str)).ToArray()";
+            var translated = stringsConverter.Body.ToReadableString();
+
+            Assert.AreEqual(EXPECTED, translated);
+        }
+
         [TestMethod]
         public void ShouldUseMethodGroupsForStaticMethods()
         {

ReadableExpressions/StringExtensions.cs

@@ -117,6 +117,9 @@ private static bool KeepSurroundingParentheses(Expression expression)
                     }
 
                     return (expression.NodeType == ExpressionType.Convert);
+
+                case ExpressionType.Lambda:
+                    return ((LambdaExpression)expression).Parameters.Count > 1;
             }
 
             return false;