Improve count on list with greater/smaller-than

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -38,6 +38,7 @@
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
 use PHPStan\Type\Accessory\AccessoryNonFalsyStringType;
 use PHPStan\Type\Accessory\HasOffsetType;
+use PHPStan\Type\Accessory\HasOffsetValueType;
 use PHPStan\Type\Accessory\HasPropertyType;
 use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\ArrayType;
@@ -1197,7 +1198,23 @@ private function specifyTypesForCountFuncCall(
 						$builderData[] = [$offsetType, $arrayType->getOffsetValueType($offsetType), !$hasOffset->yes()];
 					}
 				} else {
-					$resultTypes[] = TypeCombinator::intersect($arrayType, new NonEmptyArrayType());
+					$intersection = [];
+					$intersection[] = $arrayType;
+					$intersection[] = new NonEmptyArrayType();
+
+					$zero = new ConstantIntegerType(0);
+					foreach ($builderData as [$offsetType, $valueType, $optional]) {
+						if (
+							$optional
+							// list already is non-empty
+							|| $zero->isSuperTypeOf($offsetType)->yes()
+						) {
+							continue;
+						}
+						$intersection[] = new HasOffsetValueType($offsetType, $valueType);
+					}
+
+					$resultTypes[] = TypeCombinator::intersect(...$intersection);
 					continue;
 				}
 

tests/PHPStan/Analyser/nsrt/bug-11642.php

@@ -34,6 +34,7 @@ function doFoo() {
 	if (count($entries) !== count($payload->ids)) {
 		exit();
 	}
+	assertType('int<1, max>', count($entries));
 
 	assertType('non-empty-list<stdClass>', $entries);
 	if (count($entries) > 3) {

tests/PHPStan/Analyser/nsrt/bug-13747.php

@@ -0,0 +1,21 @@
+<?php declare(strict_types = 1);
+
+use function PHPStan\dumpType;
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/** @param list<int> $list */
+	public function sayHello($list): void
+	{
+		if (count($list) === 0) {
+			return;
+		}
+
+		if (count($list) > 2) {
+			assertType('non-empty-list<int>&hasOffsetValue(0, int)&hasOffsetValue(1, int)&hasOffsetValue(2, int)', $list);
+		} else {
+			assertType('non-empty-list<int>', $list);
+		}
+	}
+}