JS tokenizer fails to tokenize regular expression proceeded by boolean not operator

[GaryJones]

WordPress.WhiteSpace.OperatorSpacing.NoSpaceAfter (which extends Squiz_Sniffs_WhiteSpace_OperatorSpacingSniff with minimal changes) complains about the lack of whitespace in a JavaScript regex pattern.

function ga_skiplinks() {
	'use strict';
	var element = document.getElementById( location.hash.substring( 1 ) );

	if ( element ) {
		if ( ! /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) { // L21
			element.tabIndex = -1;
		}
		element.focus();
	}
}

Result:

 21 | ERROR | [x] Expected 1 space before "^"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "?"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "|"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "|"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "|"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "|"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)
 21 | ERROR | [x] Expected 1 space before "/"; 0 found (WordPress.WhiteSpace.OperatorSpacing.NoSpaceBefore)

I would expect this sniff/check to ignore JS regex patterns.

[jrfnl]

I've had a quick look. This isn't so much an issue with the sniff, as it is an issue with the JS tokenizer.

if ( /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) {}

is tokenized (correctly) as - take note of token 6/T_REGULAR_EXPRESSION:

2 :: L002 :: C1 :: T_IF :: (2) :: if
3 :: L002 :: C3 :: T_WHITESPACE :: (1) ::
4 :: L002 :: C4 :: T_OPEN_PARENTHESIS :: (1) :: (
5 :: L002 :: C5 :: T_WHITESPACE :: (1) ::
6 :: L002 :: C6 :: T_REGULAR_EXPRESSION :: (39) :: /^(?:a|select|input|button|textarea)$/i
7 :: L002 :: C45 :: T_OBJECT_OPERATOR :: (1) :: .
8 :: L002 :: C46 :: T_STRING :: (4) :: test
... etc ...

The tokenizer gets confused when the boolean not ! operator is used however.

if ( ! /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) {}

is tokenized as:

23 :: L004 :: C1 :: T_IF :: (2) :: if
24 :: L004 :: C3 :: T_WHITESPACE :: (1) ::
25 :: L004 :: C4 :: T_OPEN_PARENTHESIS :: (1) :: (
26 :: L004 :: C5 :: T_WHITESPACE :: (1) ::
27 :: L004 :: C6 :: T_BOOLEAN_NOT :: (1) :: !
28 :: L004 :: C7 :: T_WHITESPACE :: (1) ::
29 :: L004 :: C8 :: T_DIVIDE :: (1) :: /
30 :: L004 :: C9 :: T_LOGICAL_XOR :: (1) :: ^
31 :: L004 :: C10 :: T_OPEN_PARENTHESIS :: (1) :: (
32 :: L004 :: C11 :: T_INLINE_THEN :: (1) :: ?
33 :: L004 :: C12 :: T_INLINE_ELSE :: (1) :: :
34 :: L004 :: C13 :: T_STRING :: (1) :: a
35 :: L004 :: C14 :: T_BITWISE_OR :: (1) :: |
36 :: L004 :: C15 :: T_STRING :: (6) :: select
37 :: L004 :: C21 :: T_BITWISE_OR :: (1) :: |
38 :: L004 :: C22 :: T_STRING :: (5) :: input
39 :: L004 :: C27 :: T_BITWISE_OR :: (1) :: |
40 :: L004 :: C28 :: T_STRING :: (6) :: button
41 :: L004 :: C34 :: T_BITWISE_OR :: (1) :: |
42 :: L004 :: C35 :: T_STRING :: (8) :: textarea
43 :: L004 :: C43 :: T_CLOSE_PARENTHESIS :: (1) :: )
44 :: L004 :: C44 :: T_STRING :: (1) :: $
45 :: L004 :: C45 :: T_DIVIDE :: (1) :: /
46 :: L004 :: C46 :: T_STRING :: (1) :: i
47 :: L004 :: C47 :: T_OBJECT_OPERATOR :: (1) :: .
48 :: L004 :: C48 :: T_STRING :: (4) :: test
... etc ...

[GaryJones]

Thanks @jrfnl - using false === works.

In which case #1170 may be related.

[gsherwood]

@GaryJones You were right. It was the same problem as bug #1170. I needed to add an extra operator.

Thanks for the report.