Introduce ArrayPadDynamicReturnTypeExtension

conf/config.neon

@@ -1277,6 +1277,11 @@ services:
 		tags:
 			- phpstan.broker.dynamicFunctionReturnTypeExtension
 
+	-
+		class: PHPStan\Type\Php\ArrayPadDynamicReturnTypeExtension
+		tags:
+			- phpstan.broker.dynamicFunctionReturnTypeExtension
+
 	-
 		class: PHPStan\Type\Php\ArrayPopFunctionReturnTypeExtension
 		tags:

src/Type/Php/ArrayPadDynamicReturnTypeExtension.php

@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Type\Accessory\AccessoryArrayListType;
+use PHPStan\Type\Accessory\NonEmptyArrayType;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\IntegerType;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
+
+final class ArrayPadDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
+{
+
+	public function isFunctionSupported(FunctionReflection $functionReflection): bool
+	{
+		return $functionReflection->getName() === 'array_pad';
+	}
+
+	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): ?Type
+	{
+		if (!isset($functionCall->getArgs()[2])) {
+			return null;
+		}
+
+		$arrayType = $scope->getType($functionCall->getArgs()[0]->value);
+		$itemType = $scope->getType($functionCall->getArgs()[2]->value);
+
+		$returnType = new ArrayType(
+			TypeCombinator::union($arrayType->getIterableKeyType(), new IntegerType()),
+			TypeCombinator::union($arrayType->getIterableValueType(), $itemType),
+		);
+
+		$lengthType = $scope->getType($functionCall->getArgs()[1]->value);
+		if (
+			$arrayType->isIterableAtLeastOnce()->yes()
+			|| $lengthType->isSuperTypeOf(new ConstantIntegerType(0))->no()
+		) {
+			$returnType = TypeCombinator::intersect($returnType, new NonEmptyArrayType());
+		}
+
+		if ($arrayType->isList()->yes()) {
+			$returnType = TypeCombinator::intersect($returnType, new AccessoryArrayListType());
+		}
+
+		return $returnType;
+	}
+
+}

tests/PHPStan/Analyser/nsrt/array_pad.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace ArrayPad;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/**
+	 * @param array<string, string> 	      $arrayString
+	 * @param array<int, int>       		  $arrayInt
+	 * @param non-empty-array<string, string> $nonEmptyArrayString
+	 * @param non-empty-array<int, int>       $nonEmptyArrayInt
+	 * @param list<string> 					  $listString
+	 * @param list<int>       				  $listInt
+	 * @param non-empty-list<string> 		  $nonEmptyListString
+	 * @param non-empty-list<int>             $nonEmptyListInt
+	 * @param int							  $int
+	 * @param positive-int					  $positiveInt
+	 * @param negative-int					  $negativeInt
+	 * @param positive-int|negative-int		  $nonZero
+	 */
+	public function test(
+		$arrayString,
+		$arrayInt,
+		$nonEmptyArrayString,
+		$nonEmptyArrayInt,
+		$listString,
+		$listInt,
+		$nonEmptyListString,
+		$nonEmptyListInt,
+		$int,
+		$positiveInt,
+		$negativeInt,
+		$nonZero,
+	): void
+	{
+		assertType('array<int|string, string>', array_pad($arrayString, $int, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($arrayString, $positiveInt, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($arrayString, $negativeInt, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($arrayString, $nonZero, 'foo'));
+
+		assertType('array<int, \'foo\'|int>', array_pad($arrayInt, $int, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($arrayInt, $positiveInt, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($arrayInt, $negativeInt, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($arrayInt, $nonZero, 'foo'));
+
+		assertType('non-empty-array<int|string, string>', array_pad($nonEmptyArrayString, $int, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($nonEmptyArrayString, $positiveInt, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($nonEmptyArrayString, $negativeInt, 'foo'));
+		assertType('non-empty-array<int|string, string>', array_pad($nonEmptyArrayString, $nonZero, 'foo'));
+
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($nonEmptyArrayInt, $int, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($nonEmptyArrayInt, $positiveInt, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($nonEmptyArrayInt, $negativeInt, 'foo'));
+		assertType('non-empty-array<int, \'foo\'|int>', array_pad($nonEmptyArrayInt, $nonZero, 'foo'));
+
+		assertType('list<string>', array_pad($listString, $int, 'foo'));
+		assertType('non-empty-list<string>', array_pad($listString, $positiveInt, 'foo'));
+		assertType('non-empty-list<string>', array_pad($listString, $negativeInt, 'foo'));
+		assertType('non-empty-list<string>', array_pad($listString, $nonZero, 'foo'));
+
+		assertType('list<\'foo\'|int>', array_pad($listInt, $int, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($listInt, $positiveInt, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($listInt, $negativeInt, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($listInt, $nonZero, 'foo'));
+
+		assertType('non-empty-list<string>', array_pad($nonEmptyListString, $int, 'foo'));
+		assertType('non-empty-list<string>', array_pad($nonEmptyListString, $positiveInt, 'foo'));
+		assertType('non-empty-list<string>', array_pad($nonEmptyListString, $negativeInt, 'foo'));
+		assertType('non-empty-list<string>', array_pad($nonEmptyListString, $nonZero, 'foo'));
+
+		assertType('non-empty-list<\'foo\'|int>', array_pad($nonEmptyListInt, $int, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($nonEmptyListInt, $positiveInt, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($nonEmptyListInt, $negativeInt, 'foo'));
+		assertType('non-empty-list<\'foo\'|int>', array_pad($nonEmptyListInt, $nonZero, 'foo'));
+	}
+}