StrlenFunctionReturnTypeExtension: cover more scalar types

Author: staabm

src/Type/Php/StrlenFunctionReturnTypeExtension.php

@@ -6,9 +6,12 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\BooleanType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\IntegerRangeType;
+use PHPStan\Type\IntegerType;
+use PHPStan\Type\TypeUtils;
 
 class StrlenFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -30,8 +33,41 @@ public function getTypeFromFunctionCall(
 		}
 
 		$argType = $scope->getType($args[0]->value);
+
+		$constantStrings = TypeUtils::getConstantStrings($argType);
+		$min = null;
+		$max = null;
+		foreach ($constantStrings as $constantString) {
+			$len = strlen($constantString->getValue());
+
+			if ($min === null) {
+				$min = $len;
+				$max = $len;
+			}
+
+			if ($len < $min) {
+				$min = $len;
+			}
+			if ($len <= $max) {
+				continue;
+			}
+
+			$max = $len;
+		}
+
+		// $max is always != null, when $min is != null
+		if ($min !== null) {
+			return IntegerRangeType::fromInterval($min, $max);
+		}
+
+		$bool = new BooleanType();
+		if ($bool->isSuperTypeOf($argType)->yes()) {
+			return IntegerRangeType::fromInterval(0, 1);
+		}
+
 		$isNonEmpty = $argType->isNonEmptyString();
-		if ($isNonEmpty->yes()) {
+		$integer = new IntegerType();
+		if ($isNonEmpty->yes() || $integer->isSuperTypeOf($argType)->yes()) {
 			return IntegerRangeType::fromInterval(1, null);
 		}
 

tests/PHPStan/Analyser/data/bug-5129.php

@@ -20,7 +20,7 @@ public function sayHello(string $s): void
 		assertType('0', strlen($this->foo));
 
 		$this->foo = 'x';
-		assertType('int<1, max>', strlen($this->foo));
+		assertType('1', strlen($this->foo));
 		if (strlen($this->foo) > 0) {
 			return;
 		}

tests/PHPStan/Analyser/data/non-empty-string.php

@@ -302,8 +302,9 @@ class MoreNonEmptyStringFunctions
 
 	/**
 	 * @param non-empty-string $nonEmpty
+	 * @param '1'|'2'|'5'|'10' $constUnion
 	 */
-	public function doFoo(string $s, string $nonEmpty, int $i)
+	public function doFoo(string $s, string $nonEmpty, int $i, bool $bool, $constUnion)
 	{
 		assertType('string', addslashes($s));
 		assertType('non-empty-string', addslashes($nonEmpty));
@@ -349,8 +350,12 @@ public function doFoo(string $s, string $nonEmpty, int $i)
 		assertType('non-empty-string', vsprintf($nonEmpty, []));
 
 		assertType('0', strlen(''));
+		assertType('5', strlen('hallo'));
+		assertType('int<0, 1>', strlen($bool));
+		assertType('int<1, max>', strlen($i));
 		assertType('int<0, max>', strlen($s));
 		assertType('int<1, max>', strlen($nonEmpty));
+		assertType('int<1, 2>', strlen($constUnion));
 
 		assertType('non-empty-string', str_pad($nonEmpty, 0));
 		assertType('non-empty-string', str_pad($nonEmpty, 1));