Make the parser understand completely empty single line if statements

Author: MDoerner

Rubberduck.Parsing/Grammar/VBAParser.g4

@@ -421,7 +421,7 @@ 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 whiteSpace? emptyThenStatement? 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:

RubberduckTests/Grammar/VBAParserTests.cs

@@ -4012,6 +4012,27 @@ public void ParserCanDealWithMultiplyLineContinuedMemberAccess(string lineContin
             AssertTree(parseResult.Item1, parseResult.Item2, "//lExpression", matches => matches.Count == 3);
         }
 
+
+        // Adapted from opened issue https://github.com/rubberduck-vba/Rubberduck/issues/6163
+        [Test]
+        [TestCase(@"If True Then:")]
+        [TestCase(@"If True Then: ")]
+        [TestCase(@"If True Then: 
+")]
+        [TestCase(@"         If True Then::::::::::::: _
+             :::::::::::::::: _
+             :::")]
+        [TestCase(@"         If True Then::::::::::::: _
+             :::::::::::::::: _
+             :::Else")]
+        public void ParserCanDealWithStatementSeparateorsInOneLineIfStatements(string oneLineIfStatement)
+        {
+            string code = $"Sub Test()\r\n {oneLineIfStatement}\r\nEnd Sub";
+            var parseResult = Parse(code);
+            AssertTree(parseResult.Item1, parseResult.Item2, "//singleLineIfStmt", matches => matches.Count == 1);
+        }
+
+
         // Adapted from opened issue https://github.com/rubberduck-vba/Rubberduck/issues/4875
         [Test]
         [TestCase("form.Line (0, 0)-(12, 12), RGB(255, 255, 0), B")]