Improve loose comparison on union type

Author: staabm

src/Type/UnionType.php

@@ -676,7 +676,21 @@ public function isScalar(): TrinaryLogic
 
 	public function looseCompare(Type $type, PhpVersion $phpVersion): BooleanType
 	{
-		return new BooleanType();
+		$lastResult = null;
+		foreach ($this->types as $innerType) {
+			$result = $innerType->looseCompare($type, $phpVersion);
+			if ($lastResult === null) {
+				$lastResult = $result;
+				continue;
+			}
+			if ($lastResult->equals($result)) {
+				continue;
+			}
+
+			return new BooleanType();
+		}
+
+		return $lastResult ?? new BooleanType();
 	}
 
 	public function isOffsetAccessible(): TrinaryLogic

tests/PHPStan/Analyser/nsrt/loose-comparisons.php

@@ -653,4 +653,49 @@ public function sayInt(
 
 	}
 
+	/**
+	 * @param true|1|"1" $looseOne
+	 * @param false|0|"0" $looseZero
+	 * @param false|1 $constMix
+	 */
+	public function sayConstUnion(
+		$looseOne,
+		$looseZero,
+		$constMix
+	): void
+	{
+		assertType('true', $looseOne == 1);
+		assertType('false', $looseOne == 0);
+		assertType('true', $looseOne == true);
+		assertType('false', $looseOne == false);
+		assertType('true', $looseOne == "1");
+		assertType('false', $looseOne == "0");
+		assertType('false', $looseOne == []);
+
+		assertType('false', $looseZero == 1);
+		assertType('true', $looseZero == 0);
+		assertType('false', $looseZero == true);
+		assertType('true', $looseZero == false);
+		assertType('false', $looseZero == "1");
+		assertType('true', $looseZero == "0");
+		assertType('bool', $looseZero == []);
+
+		assertType('bool', $constMix == 0);
+		assertType('bool', $constMix == 1);
+		assertType('bool', $constMix == true);
+		assertType('bool', $constMix == false);
+		assertType('bool', $constMix == "1");
+		assertType('bool', $constMix == "0");
+		assertType('bool', $constMix == []);
+
+		assertType('true', $looseOne == $looseOne);
+		assertType('true', $looseZero == $looseZero);
+		assertType('false', $looseOne == $looseZero);
+		assertType('false', $looseZero == $looseOne);
+		assertType('bool', $looseOne == $constMix);
+		assertType('bool', $constMix == $looseOne);
+		assertType('bool', $looseZero == $constMix);
+		assertType('bool', $constMix == $looseZero);
+	}
+
 }

tests/PHPStan/Rules/Comparison/ConstantLooseComparisonRuleTest.php

@@ -181,12 +181,10 @@ public function testBug11694(): void
 				[
 					"Loose comparison using == between '13foo' and int<10, 20> will always evaluate to false.",
 					29,
-					'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.',
 				],
 				[
 					"Loose comparison using == between int<10, 20> and '13foo' will always evaluate to false.",
 					30,
-					'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.',
 				],
 			]);
 		}