Add rule to validate parameters to random_int()

phpstan · Jan 12, 2020 · fd1ad58 · fd1ad58
1 parent 29dbab0
commit fd1ad58
Show file tree

Hide file tree

Showing 4 changed files with 187 additions and 0 deletions.
diff --git a/conf/config.level0.neon b/conf/config.level0.neon
@@ -27,6 +27,7 @@ rules:
 	- PHPStan\Rules\Functions\InnerFunctionRule
 	- PHPStan\Rules\Functions\NonExistentDefinedFunctionRule
 	- PHPStan\Rules\Functions\PrintfParametersRule
+	- PHPStan\Rules\Functions\RandomIntParametersRule
 	- PHPStan\Rules\Methods\ExistingClassesInTypehintsRule
 	- PHPStan\Rules\Properties\AccessPropertiesInAssignRule
 	- PHPStan\Rules\Properties\AccessStaticPropertiesInAssignRule

diff --git a/src/Rules/Functions/RandomIntParametersRule.php b/src/Rules/Functions/RandomIntParametersRule.php
@@ -0,0 +1,100 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\IntegerRangeType;
+use PHPStan\Type\VerbosityLevel;
+
+/**
+ * @implements \PHPStan\Rules\Rule<\PhpParser\Node\Expr\FuncCall>
+ */
+class RandomIntParametersRule implements \PHPStan\Rules\Rule
+{
+
+	public function getNodeType(): string
+	{
+		return FuncCall::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (!($node->name instanceof \PhpParser\Node\Name)) {
+			return [];
+		}
+
+		if (strtolower((string) $node->name) !== 'random_int') {
+			return [];
+		}
+
+		$minType = $scope->getType($node->args[0]->value)->toInteger();
+		$maxType = $scope->getType($node->args[1]->value)->toInteger();
+
+		if ($minType instanceof ConstantIntegerType
+			&& $maxType instanceof ConstantIntegerType
+			&& $minType->getValue() > $maxType->getValue()
+		) {
+			return [
+				RuleErrorBuilder::message(sprintf(
+					'Cannot call random_int() with $min parameter (%d) greater than $max parameter (%d).',
+					$minType->getValue(),
+					$maxType->getValue()
+				))->build(),
+			];
+		}
+
+		if ($minType instanceof IntegerRangeType
+			&& $maxType instanceof ConstantIntegerType
+			&& $minType->getMax() > $maxType->getValue()
+		) {
+			$message = $minType->getMin() > $maxType->getValue()
+				? 'Cannot call random_int() with $min parameter (%s) greater than $max parameter (%d).'
+				: 'Cannot call random_int() when $min parameter (%s) can be greater than $max parameter (%d).';
+
+			return [
+				RuleErrorBuilder::message(sprintf(
+					$message,
+					$minType->describe(VerbosityLevel::value()),
+					$maxType->getValue()
+				))->build(),
+			];
+		}
+
+		if ($minType instanceof ConstantIntegerType
+			&& $maxType instanceof IntegerRangeType
+			&& $minType->getValue() > $maxType->getMin()
+		) {
+			$message = $minType->getValue() > $maxType->getMax()
+				? 'Cannot call random_int() with $max parameter (%s) less than $min parameter (%d).'
+				: 'Cannot call random_int() when $max parameter (%s) can be less than $min parameter (%d).';
+
+			return [
+				RuleErrorBuilder::message(sprintf(
+					$message,
+					$maxType->describe(VerbosityLevel::value()),
+					$minType->getValue()
+				))->build(),
+			];
+		}
+
+		if ($minType instanceof IntegerRangeType
+			&& $maxType instanceof IntegerRangeType
+			&& $minType->getMax() > $maxType->getMin()
+		) {
+			return [
+				RuleErrorBuilder::message(sprintf(
+					'Cannot call random_int() with intersecting $min (%s) and $max (%s) parameters.',
+					$minType->describe(VerbosityLevel::value()),
+					$maxType->describe(VerbosityLevel::value())
+				))->build(),
+			];
+		}
+
+		return [];
+	}
+
+}
diff --git a/tests/PHPStan/Rules/Functions/RandomIntParametersRuleTest.php b/tests/PHPStan/Rules/Functions/RandomIntParametersRuleTest.php
@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+/**
+ * @extends \PHPStan\Testing\RuleTestCase<RandomIntParametersRule>
+ */
+class RandomIntParametersRuleTest extends \PHPStan\Testing\RuleTestCase
+{
+
+	protected function getRule(): \PHPStan\Rules\Rule
+	{
+		return new RandomIntParametersRule();
+	}
+
+	public function testFile(): void
+	{
+		$this->analyse([__DIR__ . '/data/random-int.php'], [
+			[
+				'Cannot call random_int() with $min parameter (1) greater than $max parameter (0).',
+				8,
+			],
+			[
+				'Cannot call random_int() with $min parameter (0) greater than $max parameter (-1).',
+				9,
+			],
+			[
+				'Cannot call random_int() with $max parameter (int<-10, -1>) less than $min parameter (0).',
+				11,
+			],
+			[
+				'Cannot call random_int() when $max parameter (int<-10, 10>) can be less than $min parameter (0).',
+				12,
+			],
+			[
+				'Cannot call random_int() with $min parameter (int<1, 10>) greater than $max parameter (0).',
+				15,
+			],
+			[
+				'Cannot call random_int() when $min parameter (int<-10, 10>) can be greater than $max parameter (0).',
+				16,
+			],
+			[
+				'Cannot call random_int() with intersecting $min (int<-5, 1>) and $max (int<0, 5>) parameters.',
+				19,
+			],
+			[
+				'Cannot call random_int() with intersecting $min (int<-5, 0>) and $max (int<-1, 5>) parameters.',
+				20,
+			],
+		]);
+	}
+
+}
diff --git a/tests/PHPStan/Rules/Functions/data/random-int.php b/tests/PHPStan/Rules/Functions/data/random-int.php
@@ -0,0 +1,32 @@
+<?php
+
+random_int(0, 0);
+random_int(0, 1);
+random_int(-1, 0);
+random_int(-1, 1);
+
+random_int(1, 0);
+random_int(0, -1);
+
+random_int(0, random_int(-10, -1));
+random_int(0, random_int(-10, 10));
+random_int(0, random_int(0, 10)); // ok
+
+random_int(random_int(1, 10), 0);
+random_int(random_int(-10, 10), 0);
+random_int(random_int(-10, 0), 0); // ok
+
+random_int(random_int(-5, 1), random_int(0, 5));
+random_int(random_int(-5, 0), random_int(-1, 5));
+
+/** @var int */
+$x = foo();
+/** @var int */
+$y = bar();
+
+random_int($x, $y);
+random_int(0, $x);
+random_int($x, random_int(0, PHP_INT_MAX));
+random_int(random_int(PHP_INT_MIN, 0), $x);
+
+random_int(PHP_INT_MAX, PHP_INT_MIN); // @todo this should error