Including a return keyword and statement terminator when returning an object init from a block

Author: SteveWilkes

ReadableExpressions.UnitTests/WhenTranslatingBlocks.cs

@@ -389,6 +389,38 @@ public void ShouldIncludeAReturnKeywordForANewObjectStatement()
             Assert.AreEqual(EXPECTED.TrimStart(), translated);
         }
 
+        [TestMethod]
+        public void ShouldIncludeAReturnKeywordForAnObjectInitStatement()
+        {
+            var exception = Expression.Variable(typeof(Exception), "ex");
+            var newAddress = Expression.New(typeof(Address).GetConstructors().First());
+            var line1Property = newAddress.Type.GetMember("Line1").First();
+            var line1Value = Expression.Constant("Over here");
+            var line1Init = Expression.Bind(line1Property, line1Value);
+            var addressInit = Expression.MemberInit(newAddress, line1Init);
+            var rethrow = Expression.Rethrow(newAddress.Type);
+            var globalCatchAndRethrow = Expression.Catch(exception, rethrow);
+            var tryCatch = Expression.TryCatch(addressInit, globalCatchAndRethrow);
+
+            var tryCatchBlock = Expression.Block(tryCatch);
+
+            var translated = tryCatchBlock.ToReadableString();
+
+            const string EXPECTED = @"
+try
+{
+    return new WhenTranslatingBlocks.Address
+    {
+        Line1 = ""Over here""
+    };
+}
+catch
+{
+    throw;
+}";
+            Assert.AreEqual(EXPECTED.TrimStart(), translated);
+        }
+
         [TestMethod]
         public void ShouldIncludeAReturnKeywordForANewListInitStatement()
         {
@@ -469,5 +501,15 @@ public void ShouldIncludeAReturnKeywordForANewArrayInitStatement()
 }";
             Assert.AreEqual(EXPECTED.TrimStart(), translated);
         }
+
+        #region Helper Classes
+
+        private class Address
+        {
+            // ReSharper disable once UnusedMember.Local
+            public string Line1 { get; set; }
+        }
+
+        #endregion
     }
 }

ReadableExpressions/Extensions/InternalExpressionExtensions.cs

@@ -34,6 +34,7 @@ public static bool IsReturnable(this Expression expression)
                 case ExpressionType.Invoke:
                 case ExpressionType.ListInit:
                 case ExpressionType.MemberAccess:
+                case ExpressionType.MemberInit:
                 case ExpressionType.Multiply:
                 case ExpressionType.MultiplyChecked:
                 case ExpressionType.New:

ReadableExpressions/Translators/Formatting/CodeBlock.cs

@@ -34,11 +34,21 @@ public static bool IsSingleStatement(IList<string> blockLines)
 
             var numberOfNonIndentedLines = blockLines[0]
                 .SplitToLines()
-                .Count(line => line.IsNotIndented() && !line.StartsWith('{') && !line.StartsWith('}'));
+                .Count(RelevantNonIndentedLine);
 
             return numberOfNonIndentedLines == 1;
         }
 
+        private CodeBlock(
+            Expression expression,
+            string[] blockLines,
+            bool isASingleStatement)
+        {
+            _expression = expression;
+            _blockLines = blockLines;
+            IsASingleStatement = isASingleStatement;
+        }
+
         public bool IsASingleStatement { get; }
 
         public string AsExpressionBody()
@@ -59,19 +69,26 @@ public CodeBlock Indented()
 
             return new CodeBlock(
                 _expression,
-                _blockLines.Select(line => line.Indented()).ToArray());
+                _blockLines.Select(line => line.Indented()).ToArray(),
+                IsASingleStatement);
         }
 
         public CodeBlock Insert(params string[] lines)
         {
-            return new CodeBlock(_expression, lines.Concat(_blockLines).ToArray());
+            return new CodeBlock(
+                _expression,
+                lines.Concat(_blockLines).ToArray(),
+                isASingleStatement: false);
         }
 
         public CodeBlock Append(params string[] lines)
         {
             AddSemiColonIfRequired();
 
-            return new CodeBlock(_expression, _blockLines.Concat(lines).ToArray());
+            return new CodeBlock(
+                _expression,
+                _blockLines.Concat(lines).ToArray(),
+                isASingleStatement: false);
         }
 
         public string WithCurlyBracesIfMultiStatement()
@@ -100,9 +117,7 @@ private static bool ExpressionHasReturn(Expression expression)
         {
             while (true)
             {
-                var block = expression as BlockExpression;
-
-                if (block == null)
+                if (!(expression is BlockExpression block))
                 {
                     return expression.NodeType == ExpressionType.Goto;
                 }
@@ -140,7 +155,10 @@ private CodeBlock WithReturn()
                 return this;
             }
 
-            return new CodeBlock(_expression, GetBlockLinesWithReturnKeyword(_blockLines));
+            return new CodeBlock(
+                _expression,
+                GetBlockLinesWithReturnKeyword(_blockLines),
+                IsASingleStatement);
         }
 
         public static string InsertReturnKeyword(string multiLineStatement)
@@ -166,10 +184,24 @@ private string GetCodeBlock()
 
         private void AddSemiColonIfRequired()
         {
-            if (IsASingleStatement && !_blockLines[0].IsTerminated())
+            if (!IsASingleStatement)
             {
-                _blockLines[0] += ";";
+                return;
             }
+
+            var block = (_blockLines.Length == 1)
+                ? _blockLines[0]
+                : string.Join(" ", _blockLines);
+
+            if (!block.IsTerminated())
+            {
+                _blockLines[_blockLines.Length - 1] += ";";
+            }
+        }
+
+        private static bool RelevantNonIndentedLine(string line)
+        {
+            return line.IsNotIndented() && !line.StartsWith('{') && !line.StartsWith('}');
         }
 
         private class BlockInfo
@@ -185,7 +217,7 @@ public BlockInfo(string[] blockLines)
                 _lastNonIndentedStatement = blockLines.Last(line => line.IsNotIndented());
 
                 _lastStatementLines = _lastNonIndentedStatement.SplitToLines();
-                _lastNonIndentedLine = _lastStatementLines.Last(line => line.IsNotIndented());
+                _lastNonIndentedLine = _lastStatementLines.Last(RelevantNonIndentedLine);
             }
 
             public bool LastLineHasReturnKeyword =>