Optimize range() dynamic return type extension for big arrays

ondrejmirtes · ondrejmirtes · commit af5ba63fcf36 · 2020-12-09T16:47:51.000+01:00
diff --git a/src/Type/Php/RangeFunctionReturnTypeExtension.php b/src/Type/Php/RangeFunctionReturnTypeExtension.php
@@ -6,6 +6,7 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
@@ -14,6 +15,7 @@
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FloatType;
 use PHPStan\Type\IntegerType;
+use PHPStan\Type\IntersectionType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
@@ -60,11 +62,20 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 						continue;
 					}
 
-					$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
 					$rangeValues = range($startConstant->getValue(), $endConstant->getValue(), $stepConstant->getValue());
 					if (count($rangeValues) > self::RANGE_LENGTH_THRESHOLD) {
-						$arrayBuilder->degradeToGeneralArray();
+						return new IntersectionType([
+							new ArrayType(
+								new IntegerType(),
+								TypeCombinator::union(
+									$startConstant->generalize(),
+									$endConstant->generalize()
+								)
+							),
+							new NonEmptyArrayType(),
+						]);
 					}
+					$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
 					foreach ($rangeValues as $value) {
 						$arrayBuilder->setOffsetValueType(null, $scope->getTypeFromValue($value));
 					}
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -6100,7 +6100,7 @@ public function dataRangeFunction(): array
 				'range(3, -1)',
 			],
 			[
-				'array<int, int>',
+				'array<int, int>&nonEmpty',
 				'range(0, 50)',
 			],
 		];
diff --git a/tests/PHPStan/Analyser/data/bug-4207.php b/tests/PHPStan/Analyser/data/bug-4207.php
@@ -5,5 +5,5 @@
 use function PHPStan\Analyser\assertType;
 
 function (): void {
-	assertType('array<int, int>', range(1, 10000));
+	assertType('array<int, int>&nonEmpty', range(1, 10000));
 };

Original file line number	Diff line number	Diff line change
`@@ -6100,7 +6100,7 @@ public function dataRangeFunction(): array`
`6100`	`6100`	`'range(3, -1)',`
`6101`	`6101`	`],`
`6102`	`6102`	`[`
`6103`		`- 'array<int, int>',`
	`6103`	`+ 'array<int, int>&nonEmpty',`
`6104`	`6104`	`'range(0, 50)',`
`6105`	`6105`	`],`
`6106`	`6106`	`];`