SimpleXmlElement weirdness

[orklah]

Bug report

PHPStan thinks every direct call to an attribute on a SimpleXmlElement will return a SimpleXmlElement. This is not always true:
https://phpstan.org/r/f9336943-20db-4b3e-a9ba-671b6f58bd78
https://3v4l.org/kWSfE

While the first attribute does indeed return a SimpleXmlElement(even when the xml doesn't contain this element), this is not true for the second one.

PHPStan should not complain about always true checks in this context.

[orklah]

@ondrejmirtes you added Easy Fixes on this. Any indication how to proceed? I will try to propose the PR

[ondrejmirtes]

Relevant code: https://github.com/phpstan/phpstan-src/blob/master/src/Type/Php/SimpleXMLElementClassPropertyReflectionExtension.php, https://github.com/phpstan/phpstan-src/blob/master/src/Reflection/Php/SimpleXMLElementProperty.php. You could do new BenevolentUnionType([new ObjectType('SimpleXMLElement'), new NullType()]) and test how it works.

It's possible that BenevolentUnionType should override hasMethod, getMethod etc. methods so that level 8 does not complain about accessing something on possibly null type.

It's completely valid use-case that people are sure about their XML structure and know some attribute isn't going to be null.

[orklah]

Thanks! I will try to look at it with a clear head (so, not tomorrow night! Nor the day after!) soon.

[phpstan-bot]

@orklah PHPStan now reports different result with your code snippet:

@@ @@
+No errors
+
+PHP 7.3 – 7.4 (2 errors)
+==========
+
+6: Call to function assert() with true will always evaluate to true.
+6: Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.
+
+No errors
+
+PHP 7.1 (2 errors)
+==========
+
 6: Call to function assert() with true will always evaluate to true.
 6: Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.

Full report

PHP 8.0

No errors

PHP 7.3 – 7.4 (2 errors)

Line	Error
6	Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.
6	Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.

PHP 7.2

No errors

PHP 7.1 (2 errors)

Line	Error
6	Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.
6	Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.

[orklah]

Oh this is weird, PHP 7.2 should not be different than 7.1, 7.3 and 7.4 here.

Not sure about 8.0 though, something may have change internally.

This issue could be fixed by merging phpstan/phpstan-src#76 however

[ondrejmirtes]

@orklah Sorry, there's some weird bug with the bot and the playground, I need to look into it.

[phpstan-bot]

@orklah After the latest commit in dev-master, PHPStan now reports different result with your code snippet:

@@ @@
+4: Class SimpleXMLElement referenced with incorrect case: SimpleXmlElement.
 6: Call to function assert() with true will always evaluate to true.
+6: Class SimpleXMLElement referenced with incorrect case: SimpleXmlElement.
 6: Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.

Full report

Line	Error
4	Class SimpleXMLElement referenced with incorrect case: SimpleXmlElement.
6	Call to function assert() with true will always evaluate to true.
6	Class SimpleXMLElement referenced with incorrect case: SimpleXmlElement.
6	Instanceof between SimpleXMLElement and SimpleXMLElement will always evaluate to true.

[ondrejmirtes]

Fixed by: phpstan/phpstan-src#76

[github-actions]

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