Skip to content

Fix phpstan/phpstan#13526: False positive with array_key_exists and union types #5114

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
staabm merged 1 commit into from
Mar 1, 2026
Merged

Fix phpstan/phpstan#13526: False positive with array_key_exists and union types #5114

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 0 additions & 4 deletions src/Analyser/MutatingScope.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3680,10 +3680,6 @@ public function addTypeToExpression(Expr $expr, Type $type): self

if ($originalExprType->equals($nativeType)) {
$newType = TypeCombinator::intersect($type, $originalExprType);
if ($newType->isConstantScalarValue()->yes() && $newType->equals($originalExprType)) {
Copy link
Copy Markdown
Contributor Author

@staabm staabm Mar 1, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this code was added in the past to improve performance.

after measuring again it seems we no longer need this logic, as it seems we fixed the bottleneck somewhere else.

before this PR

➜  phpstan-src git:(2.1.x) hyperfine 'vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php' --runs=3 --warmup=1
Benchmark 1: vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php
  Time (mean ± σ):     15.854 s ±  0.095 s    [User: 15.462 s, System: 0.383 s]
  Range (min … max):   15.749 s … 15.934 s    3 runs

with deleted logic

➜  phpstan-src git:(bug13526) hyperfine 'vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php' --runs=3 --warmup=1
Benchmark 1: vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php
  Time (mean ± σ):     15.840 s ±  0.213 s    [User: 15.455 s, System: 0.375 s]
  Range (min … max):   15.642 s … 16.065 s    3 runs

// don't add the same type over and over again to improve performance
return $this;
}
return $this->specifyExpressionType($expr, $newType, $newType, TrinaryLogic::createYes());
}

Expand Down
6 changes: 6 additions & 0 deletions tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1155,4 +1155,10 @@ public function testBug11276(): void
$this->analyse([__DIR__ . '/data/bug-11276.php'], []);
}

public function testBug13526(): void
{
$this->reportPossiblyNonexistentConstantArrayOffset = true;
$this->analyse([__DIR__ . '/data/bug-13526.php'], []);
}

}
26 changes: 26 additions & 0 deletions tests/PHPStan/Rules/Arrays/data/bug-13526.php
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,26 @@
<?php declare(strict_types=1);

namespace Bug13526;

class Foo
{
public function foo(string $item, bool $a): ?int
{
$map1 = [
'MAP_1_ITEM_1' => 1,
'MAP_1_ITEM_2' => 2,
];
$map2 = [
'MAP_2_ITEM_1' => 1,
'MAP_2_ITEM_2' => 2,
];

$map = $a ? $map1 : $map2;

if (array_key_exists($item, $map)) {
return $map[$item];
}

return null;
}
}
Loading