Add operand types to DisallowedLooseComparisonRule error message

README.md

@@ -16,6 +16,7 @@
 | `switchConditionsMatchingType`         | Types in `switch` condition and `case` value must match. PHP compares them loosely by default and that can lead to  unexpected results. |
 | `dynamicCallOnStaticMethod`            | Check that statically declared methods are called statically.                                           |
 | `disallowedEmpty`                      | Disallow `empty()` - it's a very loose comparison (see [manual](https://php.net/empty)), it's recommended to use more  strict one. |
+| `disallowedLooseComparison`            | Disallow loose comparison via `==` and `!=`. |
 | `disallowedShortTernary`               | Disallow short ternary operator (`?:`) - implies weak comparison, it's recommended to use null coalesce operator (`??`)  or ternary operator with strict condition. |
 | `noVariableVariables`                  | Disallow variable variables (`$$foo`, `$this->$method()` etc.).                                         |
 | `checkAlwaysTrueInstanceof`, `checkAlwaysTrueCheckTypeFunctionCall`, `checkAlwaysTrueStrictComparison` | Always true `instanceof`, type-checking `is_*` functions and strict comparisons `===`/`!==`. These checks can be turned off by setting `checkAlwaysTrueInstanceof`, `checkAlwaysTrueCheckTypeFunctionCall` and `checkAlwaysTrueStrictComparison` to false. |

rules.neon

@@ -164,6 +164,8 @@ services:
 
 	-
 		class: PHPStan\Rules\DisallowedConstructs\DisallowedLooseComparisonRule
+		arguments:
+			includeOperandTypesInErrorMessage: %featureToggles.bleedingEdge%
 
 	-
 		class: PHPStan\Rules\BooleansInConditions\BooleanInBooleanAndRule

src/Rules/DisallowedConstructs/DisallowedLooseComparisonRule.php

@@ -9,40 +9,57 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
 
 /**
  * @implements Rule<BinaryOp>
  */
 class DisallowedLooseComparisonRule implements Rule
 {
 
+	private bool $includeOperandTypesInErrorMessage;
+
+	public function __construct(bool $includeOperandTypesInErrorMessage)
+	{
+		$this->includeOperandTypesInErrorMessage = $includeOperandTypesInErrorMessage;
+	}
+
 	public function getNodeType(): string
 	{
 		return BinaryOp::class;
 	}
 
 	public function processNode(Node $node, Scope $scope): array
 	{
+		if (!$node instanceof Equal && !$node instanceof NotEqual) {
+			return [];
+		}
+
+		$left = $scope->getType($node->left)->describe(VerbosityLevel::typeOnly());
+		$right = $scope->getType($node->right)->describe(VerbosityLevel::typeOnly());
+
 		if ($node instanceof Equal) {
 			return [
 				RuleErrorBuilder::message(
-					'Loose comparison via "==" is not allowed.',
+					$this->includeOperandTypesInErrorMessage
+						? sprintf('Loose comparison via "==" between %s and %s is not allowed.', $left, $right)
+						: 'Loose comparison via "==" is not allowed.',
 				)->tip('Use strict comparison via "===" instead.')
 					->identifier('equal.notAllowed')
 					->build(),
 			];
 		}
-		if ($node instanceof NotEqual) {
-			return [
-				RuleErrorBuilder::message(
-					'Loose comparison via "!=" is not allowed.',
-				)->tip('Use strict comparison via "!==" instead.')
-					->identifier('notEqual.notAllowed')
-					->build(),
-			];
-		}
 
-		return [];
+		return [
+			RuleErrorBuilder::message(
+				$this->includeOperandTypesInErrorMessage
+					? sprintf('Loose comparison via "!=" between %s and %s is not allowed.', $left, $right)
+					: 'Loose comparison via "!=" is not allowed.',
+			)->tip('Use strict comparison via "!==" instead.')
+				->identifier('notEqual.notAllowed')
+				->build(),
+		];
 	}
 
 }

tests/Rules/DisallowedConstructs/DisallowedLooseComparisonRuleTest.php

@@ -11,13 +11,18 @@
 class DisallowedLooseComparisonRuleTest extends RuleTestCase
 {
 
+	private bool $includeOperandTypesInErrorMessage;
+
 	protected function getRule(): Rule
 	{
-		return new DisallowedLooseComparisonRule();
+		return new DisallowedLooseComparisonRule(
+			$this->includeOperandTypesInErrorMessage,
+		);
 	}
 
-	public function testRule(): void
+	public function testRuleWithoutOperandTypesInErrorMessage(): void
 	{
+		$this->includeOperandTypesInErrorMessage = false;
 		$this->analyse([__DIR__ . '/data/weak-comparison.php'], [
 			[
 				'Loose comparison via "==" is not allowed.',
@@ -29,6 +34,83 @@ public function testRule(): void
 				5,
 				'Use strict comparison via "!==" instead.',
 			],
+			[
+				'Loose comparison via "==" is not allowed.',
+				8,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" is not allowed.',
+				10,
+				'Use strict comparison via "!==" instead.',
+			],
+			[
+				'Loose comparison via "==" is not allowed.',
+				13,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" is not allowed.',
+				15,
+				'Use strict comparison via "!==" instead.',
+			],
+			[
+				'Loose comparison via "==" is not allowed.',
+				18,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" is not allowed.',
+				20,
+				'Use strict comparison via "!==" instead.',
+			],
+		]);
+	}
+
+	public function testRuleWithOperandTypesInErrorMessage(): void
+	{
+		$this->includeOperandTypesInErrorMessage = true;
+		$this->analyse([__DIR__ . '/data/weak-comparison.php'], [
+			[
+				'Loose comparison via "==" between int and int is not allowed.',
+				3,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" between int and int is not allowed.',
+				5,
+				'Use strict comparison via "!==" instead.',
+			],
+			[
+				'Loose comparison via "==" between DateTime and float is not allowed.',
+				8,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" between float and DateTime is not allowed.',
+				10,
+				'Use strict comparison via "!==" instead.',
+			],
+			[
+				'Loose comparison via "==" between DateTime and null is not allowed.',
+				13,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" between null and DateTime is not allowed.',
+				15,
+				'Use strict comparison via "!==" instead.',
+			],
+			[
+				'Loose comparison via "==" between DateTime and DateTime is not allowed.',
+				18,
+				'Use strict comparison via "===" instead.',
+			],
+			[
+				'Loose comparison via "!=" between DateTime and DateTime is not allowed.',
+				20,
+				'Use strict comparison via "!==" instead.',
+			],
 		]);
 	}
 

tests/Rules/DisallowedConstructs/data/weak-comparison.php

@@ -4,3 +4,18 @@
 $bool2 = 123 === 456;
 $bool3 = 123 != 456;
 $bool4 = 123 !== 456;
+
+$bool5 = new DateTime('now') == 1.23;
+$bool6 = new DateTime('now') === 1.23;
+$bool7 = 1.23 != new DateTime('now');
+$bool8 = 1.23 !== new DateTime('now');
+
+$bool9 = new DateTime('now') == null;
+$bool10 = new DateTime('now') === null;
+$bool11 = null != new DateTime('now');
+$bool12 = null !== new DateTime('now');
+
+$bool13 = new DateTime('now') == new DateTime('now');
+$bool14 = new DateTime('now') === new DateTime('now');
+$bool15 = new DateTime('now') != new DateTime('now');
+$bool16 = new DateTime('now') !== new DateTime('now');