-
Notifications
You must be signed in to change notification settings - Fork 46
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Prevent exact comparison of floating-point numbers
- Loading branch information
1 parent
18c0b6e
commit 4f11909
Showing
3 changed files
with
129 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,71 @@ | ||
<?php declare(strict_types = 1); | ||
|
||
namespace PHPStan\Rules\Operators; | ||
|
||
use PhpParser\Node; | ||
use PhpParser\Node\Expr\BinaryOp; | ||
use PHPStan\Analyser\Scope; | ||
use PHPStan\Rules\Rule; | ||
use PHPStan\Type\FloatType; | ||
|
||
class OperandsInComparisonRule implements Rule | ||
{ | ||
|
||
public function getNodeType(): string | ||
{ | ||
return BinaryOp::class; | ||
} | ||
|
||
/** | ||
* @param Node $node | ||
* @param Scope $scope | ||
* @return string[] | ||
*/ | ||
public function processNode(Node $node, Scope $scope): array | ||
{ | ||
if (!$node instanceof BinaryOp\Equal | ||
&& !$node instanceof BinaryOp\Identical | ||
&& !$node instanceof BinaryOp\NotEqual | ||
&& !$node instanceof BinaryOp\NotIdentical | ||
&& !$node instanceof BinaryOp\GreaterOrEqual | ||
&& !$node instanceof BinaryOp\SmallerOrEqual | ||
) { | ||
return []; | ||
} | ||
|
||
$rightType = $scope->getType($node->right); | ||
$leftType = $scope->getType($node->left); | ||
|
||
if ($rightType instanceof FloatType || $leftType instanceof FloatType) { | ||
if ($node instanceof BinaryOp\Equal || $node instanceof BinaryOp\Identical) { | ||
return [ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) < $epsilon`, where $epsilon is maximum allowed deviation.', | ||
]; | ||
} | ||
|
||
if ($node instanceof BinaryOp\NotEqual || $node instanceof BinaryOp\NotIdentical) { | ||
return [ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
]; | ||
} | ||
|
||
if ($node instanceof BinaryOp\GreaterOrEqual) { | ||
return [ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `$left - $right >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
]; | ||
} | ||
if ($node instanceof BinaryOp\SmallerOrEqual) { | ||
return [ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `$right - $left >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
]; | ||
} | ||
} | ||
|
||
return []; | ||
} | ||
|
||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,51 @@ | ||
<?php declare(strict_types = 1); | ||
|
||
namespace PHPStan\Rules\Operators; | ||
|
||
use PHPStan\Rules\Rule; | ||
|
||
class OperandsInComparisonRuleTest extends \PHPStan\Testing\RuleTestCase | ||
{ | ||
|
||
protected function getRule(): Rule | ||
{ | ||
return new OperandsInComparisonRule(); | ||
} | ||
|
||
public function testRule(): void | ||
{ | ||
$this->analyse([__DIR__ . '/data/operators.php'], [ | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) < $epsilon`, where $epsilon is maximum allowed deviation.', | ||
113, | ||
], | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) < $epsilon`, where $epsilon is maximum allowed deviation.', | ||
114, | ||
], | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
115, | ||
], | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `abs($left - $right) >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
116, | ||
], | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `$left - $right >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
117, | ||
], | ||
[ | ||
'Exact comparison of floating-point numbers is not accurate.' . PHP_EOL | ||
. 'You should use `$right - $left >= $epsilon`, where $epsilon is maximum allowed deviation.', | ||
118, | ||
], | ||
]); | ||
} | ||
|
||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters