Null coalescing operator (??) not detected as a token

[joelposti]

I’m extending Squiz.WhiteSpace.OperatorSpacing to check for whitespace around elvis operator (?:) and null coalescing operator (??). I already managed to get the sniff to work correctly with elvis operator. The sniff is registered to listen to tokens T_INLINE_THEN and T_INLINE_ELSE which match the elvis operator correctly. I would have guessed that null coalescing operator would be equal to two T_INLINE_THEN tokens, but instead the operator is not detected at all. I could not find a token for the operator in CodeSniffer/Tokens.php.

[aik099]

I think token isn't supported currently and isn't considered as operator token. I've sent #844 PR before to add support for T_SPACESHIP token. You can send new PR for ?? operator using my PR as base.

[aik099]

elvis operator

Elvis operator, really? Maybe you wanted to say elseif operator?

[aik099]

Another thing is that PHP < 7.0 needs to recognize this new PHP 7 token as well to ease test writing. Example to T_SPACESHIP token can be found in c5fda3e commit.

[joelposti]

Thanks for the pull request tip! However, I do not believe we can add support for the null coalescing operator as easily because PHP itself does not provide a token for the operator (https://secure.php.net/manual/en/tokens.php). I believe it is required to code support for the operator into CodeSniffer/Tokenizers/PHP.php.

I really did mean to say elvis operator. Elvis operator is a compression of the ternary operator. $oof = $foo ?: $bar is equal to $oof = $foo ? $foo : $bar. https://en.wikipedia.org/wiki/Elvis_operator

[aik099]

However, I do not believe we can add support for the null coalescing operator as easily because PHP itself does not provide a token for the operator (https://secure.php.net/manual/en/tokens.php)

That's not a problem. PHP_CodeSniffer has many useful tokens, that PHP tokenizer doesn't provide.

[joelposti]

I found out the token name while running phpcs in extra verbose mode (-vv). The token is T_COALESCE. If there is a space between the question marks (syntax error), they are recognized as two T_INLINE_THEN tokens. I’m in the process of creating a pull request.

[gsherwood]

Thanks for the report and the fix.