Rules to only allow loose comparison with numeric operands

README.md

@@ -9,6 +9,7 @@
 * Require booleans in `if`, `elseif`, ternary operator, after `!`, and on both sides of `&&` and `||`.
 * Require numeric operands or arrays in `+` and numeric operands in `-`/`*`/`/`/`**`/`%`.
 * Require numeric operand in `$var++`, `$var--`, `++$var`and `--$var`.
+* Require numeric operands or `DateTimeInterface` objects in loose comparison `==`/`!=`/`<`/`>`/`<=`/`>=`/`<=>`. Configure this by setting `allowedLooseComparison` to any (union) type (default `int|float|DateTimeInterface`).
 * These functions contain a `$strict` parameter for better type safety, it must be set to `true`:
   * `in_array` (3rd parameter)
   * `array_search` (3rd parameter)

rules.neon

@@ -9,6 +9,10 @@ parameters:
 	checkMissingClosureNativeReturnTypehintRule: true
 	reportMaybesInMethodSignatures: true
 	reportStaticMethodSignatures: true
+	allowedLooseComparison: int|float|DateTimeInterface
+
+parametersSchema:
+	allowedLooseComparison: string()
 
 rules:
 	- PHPStan\Rules\BooleansInConditions\BooleanInBooleanAndRule
@@ -33,6 +37,14 @@ rules:
 	- PHPStan\Rules\Operators\OperandsInArithmeticModuloRule
 	- PHPStan\Rules\Operators\OperandsInArithmeticMultiplicationRule
 	- PHPStan\Rules\Operators\OperandsInArithmeticSubtractionRule
+	- PHPStan\Rules\Operators\OperandsInComparisonEqualRule
+	- PHPStan\Rules\Operators\OperandsInComparisonGreaterOrEqualRule
+	- PHPStan\Rules\Operators\OperandsInComparisonGreaterRule
+	- PHPStan\Rules\Operators\OperandsInComparisonNotEqualRule
+	- PHPStan\Rules\Operators\OperandsInComparisonSmallerOrEqualRule
+	- PHPStan\Rules\Operators\OperandsInComparisonSmallerRule
+	- PHPStan\Rules\Operators\OperandsInComparisonSpaceshipRule
+	- PHPStan\Rules\Properties\MissingPropertyTypehintRule
 	- PHPStan\Rules\StrictCalls\DynamicCallOnStaticMethodsRule
 	- PHPStan\Rules\StrictCalls\StrictFunctionCallsRule
 	- PHPStan\Rules\SwitchConditions\MatchingTypeInSwitchCaseConditionRule
@@ -46,6 +58,8 @@ services:
 		class: PHPStan\Rules\BooleansInConditions\BooleanRuleHelper
 	-
 		class: PHPStan\Rules\Operators\OperatorRuleHelper
+		arguments:
+			allowedLooseComparison: %allowedLooseComparison%
 	-
 		class: PHPStan\Rules\VariableVariables\VariablePropertyFetchRule
 		arguments:

src/Rules/Operators/OperandsInComparisonEqualRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonEqualRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\Equal::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\Equal $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in ==, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in ==, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}

src/Rules/Operators/OperandsInComparisonGreaterOrEqualRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonGreaterOrEqualRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\GreaterOrEqual::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\Equal $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in >=, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in >=, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}

src/Rules/Operators/OperandsInComparisonGreaterRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonGreaterRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\Greater::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\Equal $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in >, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in >, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}

src/Rules/Operators/OperandsInComparisonNotEqualRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonNotEqualRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\NotEqual::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\BooleanAnd $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in !=, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in !=, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}

src/Rules/Operators/OperandsInComparisonSmallerOrEqualRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonSmallerOrEqualRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\SmallerOrEqual::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\Equal $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in <=, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in <=, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}

src/Rules/Operators/OperandsInComparisonSmallerRule.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Operators;
+
+use PHPStan\Type\VerbosityLevel;
+
+class OperandsInComparisonSmallerRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var OperatorRuleHelper */
+	private $helper;
+
+	public function __construct(OperatorRuleHelper $helper)
+	{
+		$this->helper = $helper;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node\Expr\BinaryOp\Smaller::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Expr\BinaryOp\Equal $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(\PhpParser\Node $node, \PHPStan\Analyser\Scope $scope): array
+	{
+		$leftType = $scope->getType($node->left);
+		$rightType = $scope->getType($node->right);
+
+		$messages = [];
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->left)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in <, %s given on the left side.',
+				$this->helper->getAllowedLooseComparison(),
+				$leftType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+		if (!$this->helper->isValidForLooseComparisonOperation($scope, $node->right)) {
+			$messages[] = sprintf(
+				'Only %s is allowed in <, %s given on the right side.',
+				$this->helper->getAllowedLooseComparison(),
+				$rightType->describe(VerbosityLevel::typeOnly())
+			);
+		}
+
+		return $messages;
+	}
+
+}