Fix count inferences

Author: VincentLanglet

src/Analyser/TypeSpecifier.php

@@ -1107,6 +1107,7 @@ private function specifyTypesForCountFuncCall(
 			if (
 				$sizeType instanceof ConstantIntegerType
 				&& $sizeType->getValue() < ConstantArrayTypeBuilder::ARRAY_COUNT_LIMIT
+				&& $isList->yes()
 				&& $arrayType->getKeyType()->isSuperTypeOf(IntegerRangeType::fromInterval(0, $sizeType->getValue() - 1))->yes()
 			) {
 				// turn optional offsets non-optional
@@ -1123,6 +1124,7 @@ private function specifyTypesForCountFuncCall(
 				$sizeType instanceof IntegerRangeType
 				&& $sizeType->getMin() !== null
 				&& $sizeType->getMin() < ConstantArrayTypeBuilder::ARRAY_COUNT_LIMIT
+				&& $isList->yes()
 				&& $arrayType->getKeyType()->isSuperTypeOf(IntegerRangeType::fromInterval(0, ($sizeType->getMax() ?? $sizeType->getMin()) - 1))->yes()
 			) {
 				$builderData = [];
@@ -1168,7 +1170,7 @@ private function specifyTypesForCountFuncCall(
 				continue;
 			}
 
-			$resultTypes[] = $arrayType;
+			$resultTypes[] = TypeCombinator::intersect($arrayType, new NonEmptyArrayType());
 		}
 
 		return $this->create($countFuncCall->getArgs()[0]->value, TypeCombinator::union(...$resultTypes), $context, $scope)->setRootExpr($rootExpr);

tests/PHPStan/Analyser/nsrt/bug-13111.php

@@ -0,0 +1,13 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13111;
+
+use function PHPStan\Testing\assertType;
+
+/** @return array{0?: string, 1?: int} */
+function foo() { return [1 => 8]; }
+
+$b = foo();
+if (count($b) === 1) {
+	assertType('non-empty-array{0?: string, 1?: int}', $b);
+}

tests/PHPStan/Analyser/nsrt/list-count.php

@@ -407,7 +407,7 @@ protected function testOptionalKeysInUnionListWithIntRange($row, $listRow, $twoO
 	protected function testOptionalKeysInUnionArrayWithIntRange($row, $twoOrThree): void
 	{
 		if (count($row) >= $twoOrThree) {
-			assertType('array{0: int, 1: string|null, 2?: int|null}', $row);
+			assertType('array{0: int, 1?: string|null, 2?: int|null, 3?: float|null}', $row);
 		} else {
 			assertType('array{0: int, 1?: string|null, 2?: int|null, 3?: float|null}|array{string}', $row);
 		}