Preserve extended methods from class-based types in SchemaExtender::extend()

[abdullahseba]

Resolves #933

[spawnia]

It seems like extending class-based scalar types does not work at all as of now, given the implementation of SchemaExtender:

graphql-php/src/Utils/SchemaExtender.php

Lines 132 to 143 in 2abac8c

	protected static function extendScalarType(ScalarType $type): CustomScalarType
	{
	return new CustomScalarType([
	'name' => $type->name,
	'description' => $type->description,
	'astNode' => $type->astNode,
	'serialize' => $type->config['serialize'] ?? null,
	'parseValue' => $type->config['parseValue'] ?? null,
	'parseLiteral' => $type->config['parseLiteral'] ?? null,
	'extensionASTNodes' => static::getExtensionASTNodes($type),
	]);
	}

The $config values do not exist in a class. How else could we extend it then? Perhaps using closures to reference the orginal scalar's methods?

'serialize' => static fn ($value) => $type->serialize($value),

[abdullahseba]

I've implemented a fix using closures as you suggested and it doesn't appear to break any tests. But at the same time, the testing for scalars is probably not compleate? Only serialize() is really tested.

[codecov]

Codecov Report

Merging #934 (472d0f6) into master (2abac8c) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master     #934      +/-   ##
============================================
+ Coverage     94.16%   94.18%   +0.01%     
  Complexity       50       50              
============================================
  Files           117      117              
  Lines          9685     9659      -26     
============================================
- Hits           9120     9097      -23     
+ Misses          565      562       -3     

Impacted Files	Coverage Δ
src/Type/Definition/InterfaceType.php	97.82% <ø> (ø)
src/Type/Definition/UnionType.php	95.45% <ø> (ø)
src/Type/Definition/ObjectType.php	98.11% <100.00%> (ø)
src/Utils/SchemaExtender.php	99.02% <100.00%> (+0.52%)	⬆️
src/Type/Definition/CustomScalarType.php	95.65% <0.00%> (+4.34%)	⬆️

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[spawnia]

I've implemented a fix using closures as you suggested and it doesn't appear to break any tests. But at the same time, the testing for scalars is probably not compleate? Only serialize() is really tested.

I cut down the test case to be as minimal as possible and cover all three methods.

[simPod]

no objections, some nits

👍🏾

[simPod]

Suggested change

	* @param ListOfType|NonNull|(Type &NamedType) $typeDef
	* @param ListOfType|NonNull|(Type&NamedType) $typeDef

[spawnia]

I would prefer that, PHP_CS keeps messing it up. I don't like that tool, php-cs-fixer does a much better job in my experience.