Check for boolean in while conditions

Author: VincentLanglet

README.md

@@ -7,6 +7,7 @@
 [PHPStan](https://phpstan.org/) focuses on finding bugs in your code. But in PHP there's a lot of leeway in how stuff can be written. This repository contains additional rules that revolve around strictly and strongly typed code with no loose casting for those who want additional safety in extremely defensive programming:
 
 * Require booleans in `if`, `elseif`, ternary operator, after `!`, and on both sides of `&&` and `||`.
+* Require booleans in `while` and `do while` loop conditions.
 * Require numeric operands or arrays in `+` and numeric operands in `-`/`*`/`/`/`**`/`%`.
 * Require numeric operand in `$var++`, `$var--`, `++$var`and `--$var`.
 * These functions contain a `$strict` parameter for better type safety, it must be set to `true`:
@@ -64,6 +65,7 @@ parameters:
 	strictRules:
 		disallowedLooseComparison: false
 		booleansInConditions: false
+		booleansInLoopConditions: false
 		uselessCast: false
 		requireParentConstructorCall: false
 		disallowedBacktick: false

rules.neon

@@ -15,6 +15,7 @@ parameters:
 		allRules: true
 		disallowedLooseComparison: %strictRules.allRules%
 		booleansInConditions: %strictRules.allRules%
+		booleansInLoopConditions: [%strictRules.allRules%, %featureToggles.bleedingEdge%]
 		uselessCast: %strictRules.allRules%
 		requireParentConstructorCall: %strictRules.allRules%
 		disallowedBacktick: %strictRules.allRules%
@@ -37,6 +38,7 @@ parametersSchema:
 		allRules: anyOf(bool(), arrayOf(bool())),
 		disallowedLooseComparison: anyOf(bool(), arrayOf(bool())),
 		booleansInConditions: anyOf(bool(), arrayOf(bool()))
+		booleansInLoopConditions: anyOf(bool(), arrayOf(bool()))
 		uselessCast: anyOf(bool(), arrayOf(bool()))
 		requireParentConstructorCall: anyOf(bool(), arrayOf(bool()))
 		disallowedBacktick: anyOf(bool(), arrayOf(bool()))
@@ -64,12 +66,16 @@ conditionalTags:
 		phpstan.rules.rule: %strictRules.booleansInConditions%
 	PHPStan\Rules\BooleansInConditions\BooleanInBooleanOrRule:
 		phpstan.rules.rule: %strictRules.booleansInConditions%
+	PHPStan\Rules\BooleansInConditions\BooleanInDoWhileConditionRule:
+		phpstan.rules.rule: %strictRules.booleansInLoopConditions%
 	PHPStan\Rules\BooleansInConditions\BooleanInElseIfConditionRule:
 		phpstan.rules.rule: %strictRules.booleansInConditions%
 	PHPStan\Rules\BooleansInConditions\BooleanInIfConditionRule:
 		phpstan.rules.rule: %strictRules.booleansInConditions%
 	PHPStan\Rules\BooleansInConditions\BooleanInTernaryOperatorRule:
 		phpstan.rules.rule: %strictRules.booleansInConditions%
+	PHPStan\Rules\BooleansInConditions\BooleanInWhileConditionRule:
+		phpstan.rules.rule: %strictRules.booleansInLoopConditions%
 	PHPStan\Rules\Cast\UselessCastRule:
 		phpstan.rules.rule: %strictRules.uselessCast%
 	PHPStan\Rules\Classes\RequireParentConstructCallRule:
@@ -163,6 +169,9 @@ services:
 	-
 		class: PHPStan\Rules\BooleansInConditions\BooleanInBooleanOrRule
 
+	-
+		class: PHPStan\Rules\BooleansInConditions\BooleanInDoWhileConditionRule
+
 	-
 		class: PHPStan\Rules\BooleansInConditions\BooleanInElseIfConditionRule
 
@@ -172,6 +181,9 @@ services:
 	-
 		class: PHPStan\Rules\BooleansInConditions\BooleanInTernaryOperatorRule
 
+	-
+		class: PHPStan\Rules\BooleansInConditions\BooleanInWhileConditionRule
+
 	-
 		class: PHPStan\Rules\Cast\UselessCastRule
 		arguments:

src/Rules/BooleansInConditions/BooleanInDoWhileConditionRule.php

@@ -0,0 +1,46 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\BooleansInConditions;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
+
+/**
+ * @implements Rule<Node\Stmt\Do_>
+ */
+class BooleanInDoWhileConditionRule implements Rule
+{
+
+	private BooleanRuleHelper $helper;
+
+	public function __construct(BooleanRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return Node\Stmt\Do_::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if ($this->helper->passesAsBoolean($scope, $node->cond)) {
+			return [];
+		}
+
+		$conditionExpressionType = $scope->getType($node->cond);
+
+		return [
+			RuleErrorBuilder::message(sprintf(
+				'Only booleans are allowed in a do-while condition, %s given.',
+				$conditionExpressionType->describe(VerbosityLevel::typeOnly()),
+			))->identifier('doWhile.condNotBoolean')->build(),
+		];
+	}
+
+}

src/Rules/BooleansInConditions/BooleanInWhileConditionRule.php

@@ -0,0 +1,46 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\BooleansInConditions;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
+
+/**
+ * @implements Rule<Node\Stmt\While_>
+ */
+class BooleanInWhileConditionRule implements Rule
+{
+
+	private BooleanRuleHelper $helper;
+
+	public function __construct(BooleanRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return Node\Stmt\While_::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if ($this->helper->passesAsBoolean($scope, $node->cond)) {
+			return [];
+		}
+
+		$conditionExpressionType = $scope->getType($node->cond);
+
+		return [
+			RuleErrorBuilder::message(sprintf(
+				'Only booleans are allowed in a while condition, %s given.',
+				$conditionExpressionType->describe(VerbosityLevel::typeOnly()),
+			))->identifier('while.condNotBoolean')->build(),
+		];
+	}
+
+}

tests/Rules/BooleansInConditions/BooleanInDoWhileConditionRuleTest.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\BooleansInConditions;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleLevelHelper;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<BooleanInDoWhileConditionRule>
+ */
+class BooleanInDoWhileConditionRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new BooleanInDoWhileConditionRule(
+			new BooleanRuleHelper(
+				self::getContainer()->getByType(RuleLevelHelper::class),
+			),
+		);
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/conditions.php'], [
+			[
+				'Only booleans are allowed in a do-while condition, string given.',
+				60,
+			],
+		]);
+	}
+
+}

tests/Rules/BooleansInConditions/BooleanInWhileConditionRuleTest.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\BooleansInConditions;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleLevelHelper;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<BooleanInWhileConditionRule>
+ */
+class BooleanInWhileConditionRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new BooleanInWhileConditionRule(
+			new BooleanRuleHelper(
+				self::getContainer()->getByType(RuleLevelHelper::class),
+			),
+		);
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/conditions.php'], [
+			[
+				'Only booleans are allowed in a while condition, string given.',
+				55,
+			],
+		]);
+	}
+
+}

tests/Rules/BooleansInConditions/data/conditions.php

@@ -48,3 +48,13 @@
 $explicitMixed and $bool;
 $bool or $explicitMixed;
 $explicitMixed or $bool;
+
+$someBool = true;
+$someString = 'string';
+while ($someBool) { $someBool = !$someBool; }
+while ($someString) { $someString = ''; }
+
+$someBool = true;
+$someString = 'string';
+do { $someBool = !$someBool; } while ($someBool);
+do { $someString = ''; } while ($someString);