False positive: Parameter x of function y expects z, *NEVER* given

[driskell]

Bug report

When you perform an equality check between arrays, it turns the data types of the arrays to "NEVER" if they are identical, within the scope of the conditional. This seems strange as I'd expect unreachable code errors but either way it works. (So line 22 should report an error rather than the NEVER on line 23)

However, if you don't use literals and compare against a RETURNED array that has a shape, it cannot know if it will at runtime be different or not. But it still turns into NEVER. The exact same comparison but without one side being wrapped in a function works fine.

In summary: The error on line 31 should not be there. The error on line 23 is confusing and it should be an impossible message on 22.

No issue with non-identity comparison "!=".

Code snippet that reproduces the problem

https://phpstan.org/r/93c01ef0-94da-41cb-818b-e9628ba65649

Expected output

No errors.

Did PHPStan help you today? Did it make you happy in any way?

It helped me today, yesterday, the day before, and I've happily worked around this for now using != instead of !== so you can resolve in your own time 👍

[ondrejmirtes]

Hi, thank you for your kind words!

Personally I'd expect the error on line 31 to disappear (https://phpstan.org/r/7edf1fe5-c2af-4a49-a156-430ff3b74e66), all the others are expected. Aditionally line 22 should report an error (it's always false).

[driskell]

@ondrejmirtes Yes absolutely. I will update my description. I had that other error in there just to demonstrate but perhaps it wasn't necessary.

[phpstan-bot]

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

@@ @@
+18: Function returnData3() should return array<string, int> but return statement is missing.
 23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
 31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.

Full report

Line	Error
18	Function returnData3() should return array<string, int> but return statement is missing.
23	Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
31	Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.

[phpstan-bot]

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

@@ @@
+18: Function returnData3() should return array<string, int> but return statement is missing.
 23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
 26: Strict comparison using !== between array('test' => 1) and array('test' => 5) will always evaluate to true.
 31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.

Full report

Line	Error
18	Function returnData3() should return array<string, int> but return statement is missing.
23	Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
26	Strict comparison using !== between array('test' => 1) and array('test' => 5) will always evaluate to true.
31	Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.

[phpstan-bot]

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

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
+31: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

Full report

Line	Error
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
31	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

[phpstan-bot]

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

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-26: Strict comparison using !== between array('test' => 1) and array('test' => 5) will always evaluate to true.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
+26: Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.
+31: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

Full report

Line	Error
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
26	Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.
31	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

[phpstan-bot]

@driskell After the latest commit in 1.6.x, PHPStan now reports different result with your code snippet:

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+22: Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
+31: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

Full report

Line	Error
22	Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
31	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

[phpstan-bot]

@ondrejmirtes After the latest commit in 1.6.x, PHPStan now reports different result with your code snippet:

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-26: Strict comparison using !== between array('test' => 1) and array('test' => 5) will always evaluate to true.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+22: Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
+26: Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.
+31: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

Full report

Line	Error
22	Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
26	Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.
31	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

[phpstan-bot]

@driskell After the latest commit in 1.8.x, PHPStan now reports different result with your code snippet:

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+22: Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

Full report

Line	Error
22	Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.

[phpstan-bot]

@ondrejmirtes After the latest commit in 1.8.x, PHPStan now reports different result with your code snippet:

@@ @@
-23: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
-26: Strict comparison using !== between array('test' => 1) and array('test' => 5) will always evaluate to true.
-31: Parameter #1 $data of function testData expects array('test' => int), *NEVER* given.
+22: Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
+23: Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
+26: Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.

Full report

Line	Error
22	Strict comparison using !== between array{test: 1} and array{test: 1} will always evaluate to false.
23	Parameter #1 $data of function testData expects array{test: int}, *NEVER* given.
26	Strict comparison using !== between array{test: 1} and array{test: 5} will always evaluate to true.

[github-actions]

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