[TypeInfo] Add type alias support #59804

mtarld · 2025-02-18T15:59:49Z

Q	A
Branch?	7.3
Bug fix?	no
New feature?	yes
Deprecations?	no
Issues
License	MIT

Add type aliasing support in TypeContext and StringTypeResolver, which enables the read of @phpstan-type and @phpstan-import-type.

With this PR, the following code will be properly understood by TypeInfo (before, it used to throw an UnhandledException):

/**
 * @phpstan-type TypeAlias = array<string, list<bool>>
 */
final class Dummy
{
    /**
     * @var TypeAlias
     */
    public mixed $aliasedType;
}

nicolas-grekas · 2025-02-19T08:42:27Z

Note that the portable syntax (= understood by phpstan & psalm & phpstorm) is this one:
@phpstan-type TypeAlias = array<string, list<bool>>

src/Symfony/Component/TypeInfo/Tests/Fixtures/DummyWithPhpDoc.php

src/Symfony/Component/TypeInfo/Tests/Fixtures/DummyWithTypeAliases.php

Neirda24 · 2025-02-19T08:46:44Z

Note that the portable syntax (= understood by phpstan & psalm & phpstorm) is this one: @phpstan-type TypeAlias = array<string, list<bool>>

But it is not how people usually write it I think. is it ?

nicolas-grekas · 2025-02-19T08:48:35Z

They have to if they want support from their tools...

nicolas-grekas

Can you add a test case using psalm-type just to confirm phpstan's parser handles both?

Neirda24 · 2025-02-19T08:54:02Z

They have to if they want support from their tools...

hmmm IMO when this PR is merged it must not enforce one specific way of writing things with these tools. It should support both with and without =. Current projects / libraries that uses these kind of features don't always use the =. Requiring it would restrict people from using the TypeInfo on tools that did not follow the symfony requirements.

Neirda24 · 2025-02-19T08:57:50Z

They have to if they want support from their tools...

More on this. The documentation https://phpstan.org/writing-php-code/phpdoc-types#local-type-aliases doesn't even mention this. I asked Ondrej a while back on symfony's slack about this but he didn't tought it was worth adding it to documentation.

mtarld · 2025-02-19T08:57:57Z

@Neirda24, @nicolas-grekas, I updated the code/tests to make it work for @psalm-*, @phpstan-*, with and without the = so that it matches most of the use cases.

src/Symfony/Component/TypeInfo/TypeContext/TypeContextFactory.php

src/Symfony/Component/TypeInfo/Tests/Fixtures/DummyWithPhpDoc.php

src/Symfony/Component/TypeInfo/Tests/Fixtures/DummyWithTypeAliases.php

nicolas-grekas · 2025-02-19T16:26:25Z

Thank you @mtarld.

Neirda24 · 2025-02-19T16:27:55Z

So fast ! Thank you @mtarld !

carsonbot added Status: Needs Review Bug Feature TypeInfo labels Feb 18, 2025

carsonbot added this to the 7.3 milestone Feb 18, 2025

mtarld force-pushed the feat/type-aliases branch 2 times, most recently from 34dbc2f to 14c1e1e Compare February 18, 2025 16:01