Improve loose comparison on IntegerRange containing zero

Author: staabm

src/Type/IntegerRangeType.php

@@ -315,6 +315,16 @@ public function isSmallerThan(Type $otherType, PhpVersion $phpVersion): TrinaryL
 			$maxIsSmaller = (new ConstantIntegerType($this->max))->isSmallerThan($otherType, $phpVersion);
 		}
 
+		// 0 can have different results in contrast to the interval edges, see https://3v4l.org/iGoti
+		$zeroInt = new ConstantIntegerType(0);
+		if (!$zeroInt->isSuperTypeOf($this)->no()) {
+			return TrinaryLogic::extremeIdentity(
+				$zeroInt->isSmallerThan($otherType, $phpVersion),
+				$minIsSmaller,
+				$maxIsSmaller,
+			);
+		}
+
 		return TrinaryLogic::extremeIdentity($minIsSmaller, $maxIsSmaller);
 	}
 
@@ -332,6 +342,16 @@ public function isSmallerThanOrEqual(Type $otherType, PhpVersion $phpVersion): T
 			$maxIsSmaller = (new ConstantIntegerType($this->max))->isSmallerThanOrEqual($otherType, $phpVersion);
 		}
 
+		// 0 can have different results in contrast to the interval edges, see https://3v4l.org/iGoti
+		$zeroInt = new ConstantIntegerType(0);
+		if (!$zeroInt->isSuperTypeOf($this)->no()) {
+			return TrinaryLogic::extremeIdentity(
+				$zeroInt->isSmallerThanOrEqual($otherType, $phpVersion),
+				$minIsSmaller,
+				$maxIsSmaller,
+			);
+		}
+
 		return TrinaryLogic::extremeIdentity($minIsSmaller, $maxIsSmaller);
 	}
 
@@ -349,6 +369,16 @@ public function isGreaterThan(Type $otherType, PhpVersion $phpVersion): TrinaryL
 			$maxIsSmaller = $otherType->isSmallerThan((new ConstantIntegerType($this->max)), $phpVersion);
 		}
 
+		// 0 can have different results in contrast to the interval edges, see https://3v4l.org/iGoti
+		$zeroInt = new ConstantIntegerType(0);
+		if (!$zeroInt->isSuperTypeOf($this)->no()) {
+			return TrinaryLogic::extremeIdentity(
+				$otherType->isSmallerThan($zeroInt, $phpVersion),
+				$minIsSmaller,
+				$maxIsSmaller,
+			);
+		}
+
 		return TrinaryLogic::extremeIdentity($minIsSmaller, $maxIsSmaller);
 	}
 
@@ -366,6 +396,16 @@ public function isGreaterThanOrEqual(Type $otherType, PhpVersion $phpVersion): T
 			$maxIsSmaller = $otherType->isSmallerThanOrEqual((new ConstantIntegerType($this->max)), $phpVersion);
 		}
 
+		// 0 can have different results in contrast to the interval edges, see https://3v4l.org/iGoti
+		$zeroInt = new ConstantIntegerType(0);
+		if (!$zeroInt->isSuperTypeOf($this)->no()) {
+			return TrinaryLogic::extremeIdentity(
+				$otherType->isSmallerThanOrEqual($zeroInt, $phpVersion),
+				$minIsSmaller,
+				$maxIsSmaller,
+			);
+		}
+
 		return TrinaryLogic::extremeIdentity($minIsSmaller, $maxIsSmaller);
 	}
 
@@ -694,7 +734,20 @@ public function toPhpDocNode(): TypeNode
 
 	public function looseCompare(Type $type, PhpVersion $phpVersion): BooleanType
 	{
-		if ($this->isSmallerThan($type, $phpVersion)->yes() || $this->isGreaterThan($type, $phpVersion)->yes()) {
+		$zeroInt = new ConstantIntegerType(0);
+		if ($zeroInt->isSuperTypeOf($this)->no()) {
+			if ($type->isTrue()->yes()) {
+				return new ConstantBooleanType(true);
+			}
+			if ($type->isFalse()->yes()) {
+				return new ConstantBooleanType(false);
+			}
+		}
+
+		if (
+			$this->isSmallerThan($type, $phpVersion)->yes()
+			|| $this->isGreaterThan($type, $phpVersion)->yes()
+		) {
 			return new ConstantBooleanType(false);
 		}
 

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

@@ -712,7 +712,9 @@ public function sayEmptyStr(
 	 * @param array{} $emptyArr
 	 * @param 'php' $phpStr
 	 * @param '' $emptyStr
-	 * @param int<10, 20> $intRange
+	 * @param int<10, 20> $positiveIntRange
+	 * @param int<-20, -10> $negativeIntRange
+	 * @param int<-10, 10> $minusTenToTen
 	 */
 	public function sayInt(
 		$true,
@@ -731,6 +733,9 @@ public function sayInt(
 		int $intRange,
 		string $emptyStr,
 		string $phpStr,
+		int $positiveIntRange,
+		int $negativeIntRange,
+		int $minusTenToTen,
 	): void
 	{
 		assertType('bool', $int == $true);
@@ -746,8 +751,57 @@ public function sayInt(
 		assertType('false', $int == $emptyArr);
 		assertType('false', $int == $array);
 
-		assertType('false', $intRange == $emptyArr);
-		assertType('false', $intRange == $array);
+		assertType('true', $positiveIntRange == $true);
+		assertType('false', $positiveIntRange == $false);
+		assertType('false', $positiveIntRange == $one);
+		assertType('false', $positiveIntRange == $zero);
+		assertType('false', $positiveIntRange == $minusOne);
+		assertType('false', $positiveIntRange == $oneStr);
+		assertType('false', $positiveIntRange == $zeroStr);
+		assertType('false', $positiveIntRange == $minusOneStr);
+		assertType('false', $positiveIntRange == $plusOneStr);
+		assertType('false', $positiveIntRange == $null);
+		assertType('false', $positiveIntRange == $emptyArr);
+		assertType('false', $positiveIntRange == $array);
+
+		assertType('true', $negativeIntRange == $true);
+		assertType('false', $negativeIntRange == $false);
+		assertType('false', $negativeIntRange == $one);
+		assertType('false', $negativeIntRange == $zero);
+		assertType('false', $negativeIntRange == $minusOne);
+		assertType('false', $negativeIntRange == $oneStr);
+		assertType('false', $negativeIntRange == $zeroStr);
+		assertType('false', $negativeIntRange == $minusOneStr);
+		assertType('false', $negativeIntRange == $plusOneStr);
+		assertType('false', $negativeIntRange == $null);
+		assertType('false', $negativeIntRange == $emptyArr);
+		assertType('false', $negativeIntRange == $array);
+
+		// see https://3v4l.org/VudDK
+		assertType('bool', $minusTenToTen == $true);
+		assertType('bool', $minusTenToTen == $false);
+		assertType('bool', $minusTenToTen == $one);
+		assertType('bool', $minusTenToTen == $zero);
+		assertType('bool', $minusTenToTen == $minusOne);
+		assertType('bool', $minusTenToTen == $oneStr);
+		assertType('bool', $minusTenToTen == $zeroStr);
+		assertType('bool', $minusTenToTen == $minusOneStr);
+		assertType('bool', $minusTenToTen == $plusOneStr);
+		assertType('bool', $minusTenToTen == $null);
+		assertType('false', $minusTenToTen == $emptyArr);
+		assertType('false', $minusTenToTen == $array);
+
+		// see https://3v4l.org/oJl3K
+		assertType('false', $minusTenToTen < $null);
+		assertType('bool', $minusTenToTen > $null);
+		assertType('bool', $minusTenToTen <= $null);
+		assertType('true', $minusTenToTen >= $null);
+
+		// see https://3v4l.org/oRSgU
+		assertType('bool', $null < $minusTenToTen);
+		assertType('false', $null > $minusTenToTen);
+		assertType('true', $null <= $minusTenToTen);
+		assertType('bool', $null >= $minusTenToTen);
 
 		assertType('false', 5 == $emptyArr);
 		assertType('false', $emptyArr == 5);

tests/PHPStan/Rules/Comparison/ConstantLooseComparisonRuleTest.php

@@ -210,15 +210,21 @@ public function testBug11694(): void
 				39,
 				'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 true and int<10, 20> will always evaluate to true.',
+				41,
+			],
+			[
+				'Loose comparison using == between int<10, 20> and true will always evaluate to true.',
+				42,
+			],
 			[
 				'Loose comparison using == between false and int<10, 20> will always evaluate to false.',
 				44,
-				'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 false will always evaluate to false.',
 				45,
-				'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%</>.',
 			],
 		]);