correct handling of statement separators and newlines in single line if statements

Author: comintern

Rubberduck.Parsing/Grammar/VBAParser.g4

@@ -416,8 +416,9 @@ elseBlock :
 // 5.4.2.9 Single-line If Statement
 singleLineIfStmt : ifWithNonEmptyThen | ifWithEmptyThen;
 ifWithNonEmptyThen : IF whiteSpace? booleanExpression whiteSpace? THEN whiteSpace? listOrLabel (whiteSpace singleLineElseClause)?;
-ifWithEmptyThen : IF whiteSpace? booleanExpression whiteSpace? THEN endOfStatement? whiteSpace? singleLineElseClause;
+ifWithEmptyThen : IF whiteSpace? booleanExpression whiteSpace? THEN whiteSpace? emptyThenStatement? singleLineElseClause;
 singleLineElseClause : ELSE whiteSpace? listOrLabel?;
+
 // lineNumberLabel should actually be "statement-label" according to MS VBAL but they only allow lineNumberLabels:
 // A <statement-label> that occurs as the first element of a <list-or-label> element has the effect 
 // as if the <statement-label> was replaced with a <goto-statement> containing the same 
@@ -427,7 +428,9 @@ listOrLabel :
     lineNumberLabel (whiteSpace? COLON whiteSpace? sameLineStatement?)*
     | (COLON whiteSpace?)? sameLineStatement (whiteSpace? COLON whiteSpace? sameLineStatement?)*
 ;
+
 sameLineStatement : mainBlockStmt;
+emptyThenStatement : (COLON whiteSpace?)+;
 booleanExpression : expression;
 
 implementsStmt : IMPLEMENTS whiteSpace expression;

RubberduckTests/Grammar/VBAParserTests.cs

@@ -2002,6 +2002,129 @@ If False Then MsgBox True Else
             AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
         }
 
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfSingleEmptyThenEmptyElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then:: Else:
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        public void TestSingleLineIfSingleMultipleEmptyThensEmptyElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then:: _
+      :Else:
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        public void TestSingleLineIfSingleMultipleEmptyThensElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then:: _
+      :Else Bar
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfSingleEmptyMultiLineThenEmptyElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then: _
+      : Else:
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfSingleEmptyThenEmptyMultiLineElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then Else _
+      :
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfSingleEmptyThenElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then Else _
+      : Bar
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfNestedEmptyThenEmptyElse()
+        {
+            string code = @"
+Sub Test()
+      If True Then If False Then If True Then Else
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfNestedThenEmptyElse()
+        {
+            string code = @"
+Sub Test()
+      If True Then If False Then If True Then Bar Else
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfNestedEmptyThenElse()
+        {
+            string code = @"
+Sub Test()
+      If True Then If False Then If True Then Else Bar
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
+        [Category("Parser")]
+        [Test]
+        public void TestSingleLineIfSingleEmptyMultiLineThenEmptyMultiLineElse()
+        {
+            string code = @"
+Sub Test()
+      If False Then: _
+      Else _
+      :
+End Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt");
+        }
+
         [Category("Parser")]
         [Test]
         public void TestSingleLineIfImplicitGoTo()