Wrong PossiblyNullReference on if condition

[mrsuh]

Hi, i wrote a example

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    public function getProperty(): ?PropertyClass //<-- may be nullable
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') { //<-- can't be null after first condition
    echo 'ok' . PHP_EOL;
}

ERROR: PossiblyNullReference - src/test.php:27:60 - Cannot call method test on possibly null value (see https://psalm.dev/083)
if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') { //<-- can't be null after first condition

https://psalm.dev/r/1100ba2a85

I think psalm shouldn't warn because $main->getProperty() is already !== null
I found similar issue #3563, but it already fixed

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/1100ba2a85

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    public function getProperty(): ?PropertyClass //<-- may be nullable
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') { //<-- can't be null after first condition
    echo 'ok' . PHP_EOL;
}

Psalm output (using commit 8fbc8de):

ERROR: PossiblyNullReference - 27:60 - Cannot call method test on possibly null value

[muglug]

Simple getters should be assumed to be mutation-free; I need to re-evaluate the circumstances in which that occurs

[mrsuh]

thx!

[muglug]

So now this is fixed you have a bunch of possible solutions available:

• You could use the memoizeMethodCallResults flag: https://psalm.dev/r/4da4914033 (see the documentation)
• You can make the method final: https://psalm.dev/r/3a3f4ba96e
• You can make the class final: https://psalm.dev/r/3e031e963d
• You can add a @psalm-mutation-free annotation to the method: https://psalm.dev/r/91a1bb120d

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/4da4914033

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    public function getProperty(): ?PropertyClass
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() && $main->getProperty()->test() === 'test') {
    echo 'ok' . PHP_EOL;
}

Psalm output (using commit 262bb9f):

No issues!

https://psalm.dev/r/3a3f4ba96e

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    final public function getProperty(): ?PropertyClass
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') {
    echo 'ok' . PHP_EOL;
}

Psalm output (using commit 262bb9f):

No issues!

https://psalm.dev/r/3e031e963d

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

final class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    public function getProperty(): ?PropertyClass
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') {
    echo 'ok' . PHP_EOL;
}

Psalm output (using commit 262bb9f):

No issues!

https://psalm.dev/r/91a1bb120d

<?php

class PropertyClass
{
    public function test(): string
    {
        return 'test';
    }
}

class MainClass
{
    /** @var null|PropertyClass */
    public $property = null;

    /**
     * @psalm-mutation-free
     */
    public function getProperty(): ?PropertyClass
    {
        return $this->property;
    }
}

$main = new MainClass();
if (random_int(0, 1) === 1) {
    $main->property = new PropertyClass();
}

if ($main->getProperty() !== null && $main->getProperty()->test() === 'test') {
    echo 'ok' . PHP_EOL;
}

Psalm output (using commit 262bb9f):

No issues!