Infering array-keys is erroneous

[drupol]

Hi,

Recently I've been working on a tool that I was using internally to generate random typed values.
I pushed it online 3 days ago so I can use it everywhere easily, find the tool here: https://github.com/loophp/typed-generators

I noticed an issue while working on the ArrayType and I'm opening this issue to know if this issue is legit.
I reproduced the issue on the PHPStan playground here: https://phpstan.org/r/518a80cb-3a3d-460a-8bc5-e0791d732063
Sorry for the size of the snippet, while writing this issue I'm still looking for a reproducer with smaller amount of code.
I added some comments in the snippet to show you were PHPStan fails to infer the proper type.

IMHO, I think there is a bug somewhere because when changing the type definition from ArrayType<TKey|VKey, T|V> to ArrayType<VKey|TKey, T|V> (line 118), the PHPStan output is different.

The same snippet in PSalm is behaving correctly: https://psalm.dev/r/b48de03f7e

[rvanvelzen]

Using int|string instead of array-key might help here

[phpstan-bot]

@drupol After the latest push in 1.10.x, PHPStan now reports different result with your code snippet:

@@ @@
-PHP 8.0 – 8.1 (1 error)
+PHP 8.0 – 8.1 (4 errors)
 ==========
 
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
+130: PHPDoc tag @var with type list<Snippet\TypeGenerator<TKey of (int|string)>> is not subtype of native type non-empty-list<Snippet\TypeGenerator>.
+134: PHPDoc tag @var with type list<Snippet\TypeGenerator<T|V>> is not subtype of native type non-empty-list<Snippet\TypeGenerator>.
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>
 
-PHP 7.1 – 7.4 (2 errors)
+PHP 7.1 – 7.4 (5 errors)
 ==========
 
 109: Method Snippet\ArrayType::__invoke() should return array<TKey of (int|string), T> but returns array<TKey of (int|string), T>|false.
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
+130: PHPDoc tag @var with type list<Snippet\TypeGenerator<TKey of (int|string)>> is not subtype of native type non-empty-list<Snippet\TypeGenerator>.
+134: PHPDoc tag @var with type list<Snippet\TypeGenerator<T|V>> is not subtype of native type non-empty-list<Snippet\TypeGenerator>.
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>

Full report

PHP 8.0 – 8.1 (4 errors)

Line	Error
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
130	`PHPDoc tag @var with type list<Snippet\TypeGenerator<TKey of (int
134	`PHPDoc tag @var with type list<Snippet\TypeGenerator<T
148	`Expected type array<int

PHP 7.1 – 7.4 (5 errors)

Line	Error
109	`Method Snippet\ArrayType::__invoke() should return array<TKey of (int
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
130	`PHPDoc tag @var with type list<Snippet\TypeGenerator<TKey of (int
134	`PHPDoc tag @var with type list<Snippet\TypeGenerator<T
148	`Expected type array<int

[phpstan-bot]

@drupol After the latest push in 1.10.x, PHPStan now reports different result with your code snippet:

@@ @@
-PHP 8.0 – 8.1 (1 error)
+PHP 8.0 – 8.1 (2 errors)
 ==========
 
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>
 
-PHP 7.1 – 7.4 (2 errors)
+PHP 7.1 – 7.4 (3 errors)
 ==========
 
 109: Method Snippet\ArrayType::__invoke() should return array<TKey of (int|string), T> but returns array<TKey of (int|string), T>|false.
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>

Full report

PHP 8.0 – 8.1 (2 errors)

Line	Error
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
148	`Expected type array<int

PHP 7.1 – 7.4 (3 errors)

Line	Error
109	`Method Snippet\ArrayType::__invoke() should return array<TKey of (int
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
148	`Expected type array<int

[phpstan-bot]

@drupol After the latest push in 1.10.x, PHPStan now reports different result with your code snippet:

@@ @@
-PHP 8.0 – 8.1 (1 error)
+PHP 8.0 – 8.1 (3 errors)
 ==========
 
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
+134: PHPDoc tag @var with type list<Snippet\TypeGenerator<T|V>> is not subtype of type non-empty-list<Snippet\TypeGenerator<T>|Snippet\TypeGenerator<V>>.
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>
 
-PHP 7.1 – 7.4 (2 errors)
+PHP 7.1 – 7.4 (4 errors)
 ==========
 
 109: Method Snippet\ArrayType::__invoke() should return array<TKey of (int|string), T> but returns array<TKey of (int|string), T>|false.
+127: PHPDoc tag @var with type Snippet\ArrayType<TKey of (int|string), T|V> is not subtype of native type $this(Snippet\ArrayType<TKey of (int|string), T>).
+134: PHPDoc tag @var with type list<Snippet\TypeGenerator<T|V>> is not subtype of type non-empty-list<Snippet\TypeGenerator<T>|Snippet\TypeGenerator<V>>.
 148: Expected type array<int|string, int|string>, actual: array<string, int|string>

Full report

PHP 8.0 – 8.1 (3 errors)

Line	Error
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
134	`PHPDoc tag @var with type list<Snippet\TypeGenerator<T
148	`Expected type array<int

PHP 7.1 – 7.4 (4 errors)

Line	Error
109	`Method Snippet\ArrayType::__invoke() should return array<TKey of (int
127	`PHPDoc tag @var with type Snippet\ArrayType<TKey of (int
134	`PHPDoc tag @var with type list<Snippet\TypeGenerator<T
148	`Expected type array<int