Strict groups support

[Seldaek]

@staabm

I think these should be doable in a similar way you did in this PR

I am not sure how to do the non-null part. Maybe it's doable by modifying the result of $this->regexShapeMatcher->matchType() to ensure string|null becomes string.. but I suck at phpstan internals :D

If you have a sec to help any time it'd be great, I believe the tests are correct.

[staabm]

wdyt about

$ git diff
diff --git a/src/PHPStan/PregMatchTypeSpecifyingExtension.php b/src/PHPStan/PregMatchTypeSpecifyingExtension.php
index b83ed12..7ee7ec5 100644
--- a/src/PHPStan/PregMatchTypeSpecifyingExtension.php
+++ b/src/PHPStan/PregMatchTypeSpecifyingExtension.php
@@ -11,8 +11,11 @@
 use PHPStan\Analyser\TypeSpecifierContext;
 use PHPStan\Reflection\MethodReflection;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Php\RegexArrayShapeMatcher;
 use PHPStan\Type\StaticMethodTypeSpecifyingExtension;
+use PHPStan\Type\TypeCombinator;
+use PHPStan\Type\Type;

 final class PregMatchTypeSpecifyingExtension implements StaticMethodTypeSpecifyingExtension, TypeSpecifierAwareExtension
 {
@@ -70,6 +73,22 @@ public function specifyTypes(MethodReflection $methodReflection, StaticCall $nod
             return new SpecifiedTypes();
         }

+        if (
+            in_array($methodReflection->getName(), ['matchStrictGroups', 'isMatchStrictGroups'], true)
+            && $matchedType instanceof ConstantArrayType
+        ) {
+            $matchedType = new ConstantArrayType(
+                $matchedType->getKeyTypes(),
+                array_map(static function (Type $valueType): Type {
+                    return TypeCombinator::removeNull($valueType);
+
+                }, $matchedType->getValueTypes()),
+                [0],
+                [],
+                $matchedType->isList()
+            );
+        }
+
         $overwrite = false;
         if ($context->false()) {
             $overwrite = true;

I am not 100% sure, I got the difference of 'matchStrictGroups' vs. 'isMatchStrictGroups'.

the above patch removes all nullable types and also turns all groups into mandatory groups.

[staabm]

I am not 100% sure, I got the difference of 'matchStrictGroups' vs. 'isMatchStrictGroups'.

I wonder whether this even means $matches can never be the empty-array?

[Seldaek]

Yeah that looks great thanks!

I wonder whether this even means $matches can never be the empty-array?

Hmm if it matches it cannot, but it is still allowed to NOT match. It only throws if it matches but some groups are null, thus improving the type safety within the code handling the matches as we know we don't have to check for nulls.. Now with better support for optional groups etc in PHPStan this whole thing might be less needed or not at all anymore tbh. I'll have to see.

[Seldaek]

BTW there was a deprecation warning on $matchedType instanceof ConstantArrayType which I hacked around, possibly wrong :)

[Seldaek]

Woops, that does not go so well on the composer repo:

     Internal error: Internal error. while analysing file /var/www/composer/src/Composer/Repository/Vcs/GitHubDriver.php
     Post the following stack trace to https://github.com/phpstan/phpstan/issues/new?template=Bug_report.yaml:
     ## phar:///var/www/composer/vendor/phpstan/phpstan/phpstan.phar/src/Type/Constant/ConstantArrayTypeBuilder.php(150)
     #0 phar:///var/www/composer/vendor/phpstan/phpstan/phpstan.phar/src/Type/Constant/ConstantArrayType.php(576):
     PHPStan\Type\Constant\ConstantArrayTypeBuilder->setOffsetValueType()
     #1 phar:///var/www/composer/vendor/phpstan/phpstan/phpstan.phar/src/Type/TypeCombinator.php(915):
     PHPStan\Type\Constant\ConstantArrayType->setOffsetValueType()

[staabm]

how to reproduce?

[Seldaek]

in the composer project:

composer require composer/pcre:2.x-dev

And add - ../vendor/composer/pcre/extension.neon to phpstan/config.neon

Then composer phpstan crashes