From 44299db3c574935bc7939a777cb46dd024623965 Mon Sep 17 00:00:00 2001
From: Mikko Pesari <mikko@pesari.fi>
Date: Thu, 15 Jan 2026 20:28:12 +0200
Subject: [PATCH] Add operand types to DisallowedLooseComparisonRule error
 message

---
 .../DisallowedLooseComparisonRule.php         | 14 ++++++--
 .../DisallowedLooseComparisonRuleTest.php     | 34 +++++++++++++++++--
 .../data/weak-comparison.php                  | 15 ++++++++
 3 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/src/Rules/DisallowedConstructs/DisallowedLooseComparisonRule.php b/src/Rules/DisallowedConstructs/DisallowedLooseComparisonRule.php
index 70b8514f..a9f20f2c 100644
--- a/src/Rules/DisallowedConstructs/DisallowedLooseComparisonRule.php
+++ b/src/Rules/DisallowedConstructs/DisallowedLooseComparisonRule.php
@@ -9,6 +9,8 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
 
 /**
  * @implements Rule<BinaryOp>
@@ -26,7 +28,11 @@ public function processNode(Node $node, Scope $scope): array
 		if ($node instanceof Equal) {
 			return [
 				RuleErrorBuilder::message(
-					'Loose comparison via "==" is not allowed.',
+					sprintf(
+						'Loose comparison via "==" between %s and %s is not allowed.',
+						$scope->getType($node->left)->describe(VerbosityLevel::typeOnly()),
+						$scope->getType($node->right)->describe(VerbosityLevel::typeOnly()),
+					),
 				)->tip('Use strict comparison via "===" instead.')
 					->identifier('equal.notAllowed')
 					->build(),
@@ -35,7 +41,11 @@ public function processNode(Node $node, Scope $scope): array
 		if ($node instanceof NotEqual) {
 			return [
 				RuleErrorBuilder::message(
-					'Loose comparison via "!=" is not allowed.',
+					sprintf(
+						'Loose comparison via "!=" between %s and %s is not allowed.',
+						$scope->getType($node->left)->describe(VerbosityLevel::typeOnly()),
+						$scope->getType($node->right)->describe(VerbosityLevel::typeOnly()),
+					),
 				)->tip('Use strict comparison via "!==" instead.')
 					->identifier('notEqual.notAllowed')
 					->build(),
diff --git a/tests/Rules/DisallowedConstructs/DisallowedLooseComparisonRuleTest.php b/tests/Rules/DisallowedConstructs/DisallowedLooseComparisonRuleTest.php
index 9e56b583..99a33771 100644
--- a/tests/Rules/DisallowedConstructs/DisallowedLooseComparisonRuleTest.php
+++ b/tests/Rules/DisallowedConstructs/DisallowedLooseComparisonRuleTest.php
@@ -20,15 +20,45 @@ public function testRule(): void
 	{
 		$this->analyse([__DIR__ . '/data/weak-comparison.php'], [
 			[
-				'Loose comparison via "==" is not allowed.',
+				'Loose comparison via "==" between int and int is not allowed.',
 				3,
 				'Use strict comparison via "===" instead.',
 			],
 			[
-				'Loose comparison via "!=" is not allowed.',
+				'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.',
+			],
 		]);
 	}
 
diff --git a/tests/Rules/DisallowedConstructs/data/weak-comparison.php b/tests/Rules/DisallowedConstructs/data/weak-comparison.php
index 2e7e3a97..0a6a1671 100644
--- a/tests/Rules/DisallowedConstructs/data/weak-comparison.php
+++ b/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');