Extraction Coverage

A tool can only judge the patterns it finds. This page lists, call by call, which of them reads the pattern of a PHP call: regex lint, with nikic/php-parser installed or with PHP’s tokenizer alone, the language server, the PHPStan extension, the Psalm plugin, and regex:lint of the Laravel package and of the Symfony bundle.

regex lint reads the same patterns with either strategy: the test suite runs every extraction case through both. The Laravel and Symfony commands run that same extractor on PHP files, configured by their own extraction keys rather than by regex.json (see the Laravel and Symfony guides), and add what only their framework holds: route constraints and validation rules, route requirements and validator constraints. The language server takes its configuration from regex.json.

Legend:

Yes: the pattern is read.
Types: the pattern is read when the tool’s type inference knows the argument as a constant string, from any file. PHPStan reads each of the constant strings an argument may be; Psalm reads an argument whose type is one literal string, so not a variable that may hold one of two.
No: the pattern is not read.

Native calls

Call	CLI, php-parser	CLI, tokenizer	LSP	PHPStan	Psalm	Laravel	Symfony
`preg_match()` and the seven other `preg_*` functions	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Namespaced drop-ins, `Safe\preg_match()`	Yes	Yes	Yes	Yes	No	Yes	Yes
`new RegexIterator()`, `new RecursiveRegexIterator()`	Yes	Yes	Yes	No	No	Yes	Yes
`filter_var()`, `filter_input()` with `FILTER_VALIDATE_REGEXP`	Yes	Yes	Yes	No	No	Yes	Yes
`mb_ereg()`, `mb_split()` (Oniguruma, not PCRE)	No	No	No	No	No	No	No

Library calls

Every preset is read by default; extraction.interop (interop for PHPStan) narrows them. Psalm reads no preset.

Call	CLI, php-parser	CLI, tokenizer	LSP	PHPStan	Psalm	Laravel	Symfony
Static methods of `composer-pcre`, `nette-utils`, `spatie-regex`, `illuminate-support`	Yes	Yes	Yes	Yes	No	Yes	Yes
Nette’s `utf8: true` adds `u` to the pattern judged	Yes	Yes	Yes	No	No	Yes	Yes
`webmozart-assert`, `beberlei-assert`: `Assert::regex()`, `Assertion::regex()`	Yes	Yes	Yes	Yes	No	Yes	Yes
`phpunit` on `$this->`, `self::`, `static::`, `parent::`	Yes	Yes	Yes	No	No	Yes	Yes
`phpunit` on `PHPUnit\Framework\Assert::` or `TestCase::`	Yes	Yes	Yes	Yes	No	Yes	Yes
`phpunit` functions, `PHPUnit\Framework\assertMatchesRegularExpression()`	Yes	Yes	Yes	No	No	Yes	Yes
`symfony-validator`: `new Regex(...)`, `#[Assert\Regex(...)]`	Yes	Yes	Yes	No	No	Yes	Yes¹
A method called on an object of a library (`$str->match()`, `u($s)->match()`, `Assert::that($v)->regex()`)	No	No	No	No	No	No	No

¹ The Symfony bundle also reads every Regex constraint from the validator’s metadata, YAML and XML mappings included; a constraint both sources read is reported once.

Your own helpers

Call	CLI, php-parser	CLI, tokenizer	LSP	PHPStan	Psalm	Laravel	Symfony
A helper named in `extraction.functions`	Yes	Yes	Yes	No	No	Yes	Yes
A function or a static method marked `#[RegexPattern]`, called by its name	Yes	Yes	Yes	Yes	No	Yes	Yes
The same static method called through `self::`, `static::` or `parent::`	No	No	No	Yes	No	No	No
An instance method marked `#[RegexPattern]` (`$this->m()`, `$obj->m()`)	No	No	No	Yes	No	No	No
`#[RegexPattern]` declared in `vendor/`	Yes	Yes	Yes	Yes	No	Yes	Yes

How the pattern is written

Argument	CLI, php-parser	CLI, tokenizer	LSP	PHPStan	Psalm	Laravel	Symfony
A string literal	Yes	Yes	Yes	Yes	Yes	Yes	Yes
A named argument, `pattern: '/.../'`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
A named argument after a spread, `f(...$args, pattern: '/.../')`	Yes	Yes	Yes	No	No	Yes	Yes
A heredoc or a nowdoc	Yes	Yes	No²	Yes	Yes	Yes	Yes
A concatenation at the call, `'/'.self::PART.'/'`	Yes	Yes	No²	Types	Types	Yes	Yes
A constant of the same file, `self::RE`, `Patterns::RE`, `RE`	Yes	Yes	Yes	Types	Types	Yes	Yes
`static::RE` of a class that may be extended	No	No	No	No	No	No	No
A constant of another file	No	No	No	Types	Types	No	No
A local variable whose every assignment that may reach the call is a literal	Yes	Yes	Yes	Types	Types	Yes	Yes
A private or protected property of a `final` class, `$this->re`, out of a closure (protected: the class extends none)	Yes	Yes	Yes	No³	No³	Yes	Yes
A ternary or a `match` over literals	No	No	No	Types	No	No	No
A concatenation with `preg_quote()` of a text not known	No	No	No	No	No⁴	No	No

² A diagnostic needs one string literal to land in; regex lint reports these patterns, the editor does not show them.

³ A property’s type is its declared type, string, whatever its default.

⁴ Psalm types $matches from the rest of such a pattern, but judges no pattern it cannot read whole.

The rules regex lint follows to read a name, and where it reports a pattern read that way, are in the CLI guide. PHPStan and Psalm read what their own analysis proves, which reaches further in some cases and less far in others; they report a pattern at the call.

A later release may read more of these cases: see Backward compatibility.

Edit on GitHub