#463: psalm-specific type declarations for generic/intersection types of proxies

[Ocramius]

Fixes #463

This is an incomplete patch that just serves to display that types can be
improved massively in here, making even this magic contraption of a library
usable downstream with some decent type constraints.

TODOs:

• need to implement CI steps to ensure type inference works as expected
• full type coverage in ProxyManager internals (note: no tests yet - those require more work)
• pin to stable vimeo/psalm (^3.4.0)
• split type check test file into multiple type-checked examples
• raise psalm reporting levels
• add utilities for PHPStorm type inference

Blocked by:

• Cannot infer concrete type of templated type in intersection type expression vimeo/psalm#1673
• Intersection docblock order affects resultant type vimeo/psalm#1674
• Cannot infer type of templated Foo&Proxy<Foo> methods with class-string<Foo> vimeo/psalm#1675
• Sorting of @psalm-return intersection type may lead to detecting mixed instead of correct type vimeo/psalm#1677
• Inferred callable parameter types become object when templated vimeo/psalm#1679
• Too eager templated type pattern matching leads to larger templated types than the expected ones vimeo/psalm#1680
• Type declaration parent is erroneously detected as self vimeo/psalm#1681
• class-string ends up as mixed after !class_exists vimeo/psalm#1682
• @psalm-suppress not picked up on typed property declarations vimeo/psalm#1683
• class-string<T> not correctly inferred as class-string<ConcreteType> in property assignments vimeo/psalm#1722
• Renamed Fn to TFn to allow for PHP 7.4 compatibility vimeo/psalm#1726

[stof]

a PR fixing itself ? That's inception.

[Ocramius]

a PR fixing itself ?

What do you mean by that? I didn't catch the joke XD

[stof]

The description contains this:

Fixes #465

This reference is the PR itself.

[Ocramius]

Ha, fixed, thanks!

[Ocramius]

Checks took 0.66 seconds and used 153.505MB of memory
Psalm was able to infer types for 99.7795% of the codebase

This is 🔥

[Ocramius]

Ok, so my latest changes lead to wild issues in Psalm:

ERROR: UndefinedMethod - tests/static-analysis/lazy-loading-value-holder.php:57:25 - Method ProxyManager\Example\VirtualProxy\Foo::sayhello does not exist
    echo $wrappedValue->sayHello();

There is no mention of ProxyManager\Example\VirtualProxy\Foo in that file, to this feels like a global multi-file shared state issue. Not sure how to reproduce it for psalm to consume.

[muglug]

this feels like a global multi-file shared state issue

Yeah something in examples is polluting stuff - I'll find and fix

[muglug]

Fixed in vimeo/psalm@0ad5769

[Ocramius]

Hmm, since latest builds, psalm now fails with something like this on 7.4:

$ ./vendor/bin/psalm
PHP Fatal error:  Uncaught ParseError: syntax error, unexpected 'Fn' (T_FN), expecting identifier (T_STRING) in /home/travis/build/Ocramius/ProxyManager/vendor/vimeo/psalm/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFilterReturnTypeProvider.php:64

@muglug I just need to pin this to a stable release with a green build, and then I can release here 👍

[Ocramius]

I'll send a patch to fix the Fn issue btw 👍

EDIT: see vimeo/psalm#1726

[dkarlovi]

a PR fixing itself ? That's inception.

@Ocramius is just that good.

[Ocramius]

Green! Now needs a release upstream and we can 🚢 \o/

[muglug]

Will hopefully release later today, barring any major impediments

[muglug]

Boom: https://github.com/vimeo/psalm/releases/tag/3.4.0

[Ocramius]

Thanks! That should be enough to do a release here, if all is green 🚀

[Ocramius]

Relevant CI tasks are GO! 👍