support integer-ranges in pow()

phpstan · Oct 27, 2022 · e45cdcc · e45cdcc
1 parent aaf4b7d
commit e45cdcc
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diff --git a/src/Reflection/InitializerExprTypeResolver.php b/src/Reflection/InitializerExprTypeResolver.php
@@ -1172,6 +1172,66 @@ public function getPowType(Expr $left, Expr $right, callable $getTypeCallback):
 			return TypeCombinator::union(...$resultTypes);
 		}
 
+		if ($leftType instanceof IntegerRangeType && $rightType instanceof IntegerRangeType) {
+			$min = null;
+			$max = null;
+			if ($leftType->getMin() !== null && $rightType->getMin() !== null) {
+				$min = $leftType->getMin() ** $rightType->getMin();
+			}
+			if ($leftType->getMax() !== null && $rightType->getMax() !== null) {
+				$max = $leftType->getMax() ** $rightType->getMax();
+			}
+
+			if (!is_float($min) && !is_float($max)) {
+				return IntegerRangeType::fromInterval($min, $max);
+			}
+		}
+
+		if (
+			($leftType instanceof IntegerRangeType && $rightTypesCount > 0)
+			|| ($rightType instanceof IntegerRangeType && $leftTypesCount > 0)
+		) {
+			if ($leftType instanceof IntegerRangeType) {
+				$min = $leftType->getMin();
+				$max = $leftType->getMax();
+
+				$minType = $min === null ? new NullType() : $this->getPowType(new LNumber($min), $right, $getTypeCallback);
+				$maxType = $max === null ? new NullType() : $this->getPowType(new LNumber($max), $right, $getTypeCallback);
+			} elseif ($rightType instanceof IntegerRangeType) {
+				$min = $rightType->getMin();
+				$max = $rightType->getMax();
+
+				$minType = $min === null ? new NullType() : $this->getPowType($left, new LNumber($min), $getTypeCallback);
+				$maxType = $max === null ? new NullType() : $this->getPowType($left, new LNumber($max), $getTypeCallback);
+			} else {
+				throw new ShouldNotHappenException();
+			}
+
+			$minTypes = TypeUtils::getConstantIntegers($minType);
+			$maxTypes = TypeUtils::getConstantIntegers($maxType);
+
+			$resultTypes = [];
+			if (count($minTypes) === count($maxTypes)) {
+				foreach (array_keys($minTypes) as $i) {
+					$resultTypes[] = IntegerRangeType::fromInterval($minTypes[$i]->getValue(), $maxTypes[$i]->getValue());
+				}
+			} elseif (count($minTypes) === 1) {
+				$minType = $minTypes[0];
+				foreach ($maxTypes as $constantMaxType) {
+					$resultTypes[] = IntegerRangeType::fromInterval($minType->getValue(), $constantMaxType->getValue());
+				}
+			} elseif (count($maxTypes) === 1) {
+				$maxType = $maxTypes[0];
+				foreach ($minTypes as $constantMinType) {
+					$resultTypes[] = IntegerRangeType::fromInterval($constantMinType->getValue(), $maxType->getValue());
+				}
+			}
+
+			if (count($resultTypes) > 0) {
+				return TypeCombinator::union(...$resultTypes);
+			}
+		}
+
 		return $this->resolveCommonMath(new BinaryOp\Pow($left, $right), $leftType, $rightType);
 	}
 

diff --git a/tests/PHPStan/Analyser/data/pow.php b/tests/PHPStan/Analyser/data/pow.php
@@ -23,3 +23,50 @@ function (\stdClass $a, \GMP $b): void {
 	assertType('GMP|stdClass', pow($a, $b));
 	assertType('GMP|stdClass', $a ** $b);
 };
+
+function (): void {
+	$range = rand(1, 3);
+	assertType('int<1, 3>', $range);
+
+	assertType('int<1, 9>', pow($range, 2));
+	assertType('int<1, 9>', $range ** 2);
+
+	assertType('int<2, 8>', pow(2, $range));
+	assertType('int<2, 8>', 2 ** $range);
+};
+
+function (): void {
+	$range = rand(2, 3);
+	$x = 2;
+	if (rand(0, 1)) {
+		$x = 3;
+	} else if (rand(0, 10)) {
+		$x = 4;
+	}
+
+	assertType('int<4, 27>|int<16, 81>', pow($range, $x));
+	assertType('int<4, 27>|int<16, 81>', $range ** $x);
+
+	assertType('int<4, 27>|int<16, 64>', pow($x, $range));
+	assertType('int<4, 27>|int<16, 64>', $x ** $range);
+
+	assertType('int<4, 27>', pow($range, $range));
+	assertType('int<4, 27>', $range ** $range);
+};
+
+/**
+ * @param positive-int $positiveInt
+ * @param int<min, 3> $range2
+ */
+function foo($positiveInt, $range2): void {
+	$range = rand(2, 3);
+
+	assertType('int<2, max>', pow($range, $positiveInt));
+	assertType('int<2, max>', $range ** $positiveInt);
+
+	assertType('int<min, 27>', pow($range, $range2));
+	assertType('int<min, 27>', $range ** $range2);
+
+	assertType('(float|int)', pow($range, PHP_INT_MAX));
+	assertType('(float|int)', $range ** PHP_INT_MAX);
+}