Add support for integer ranges in strtotime() with constant strings

src/Type/Php/StrtotimeFunctionReturnTypeExtension.php

@@ -9,14 +9,16 @@
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeUtils;
 use function array_map;
 use function array_unique;
 use function count;
-use function is_int;
+use function gettype;
+use function min;
 use function strtotime;
 
 class StrtotimeFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
@@ -37,13 +39,28 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		if ($argType instanceof MixedType) {
 			return TypeUtils::toBenevolentUnion($defaultReturnType);
 		}
-		$result = array_unique(array_map(static fn (ConstantStringType $string): bool => is_int(strtotime($string->getValue())), TypeUtils::getConstantStrings($argType)));
+		$results = array_unique(array_map(static fn (ConstantStringType $string): int|bool => strtotime($string->getValue()), TypeUtils::getConstantStrings($argType)));
+		$resultTypes = array_unique(array_map(static fn (int|bool $value): string => gettype($value), $results));
 
-		if (count($result) !== 1) {
+		if (count($resultTypes) !== 1 || count($results) === 0) {
 			return $defaultReturnType;
 		}
 
-		return $result[0] ? new IntegerType() : new ConstantBooleanType(false);
+		if ($results[0] === false) {
+			return new ConstantBooleanType(false);
+		}
+
+		// 2nd param $baseTimestamp is too non-deterministic so simply return int
+		if (count($functionCall->getArgs()) > 1) {
+			return new IntegerType();
+		}
+
+		// if it is positive we can narrow down to positive-int as long as time flows forward
+		if (min(array_map('intval', $results)) > 0) {
+			return IntegerRangeType::createAllGreaterThan(0);
+		}
+
+		return new IntegerType();
 	}
 
 }

tests/PHPStan/Analyser/LegacyNodeScopeResolverTest.php

@@ -5249,26 +5249,6 @@ public function dataFunctions(): array
 				'(float|string)',
 				'$microtimeBenevolent',
 			],
-			[
-				'int',
-				'$strtotimeNow',
-			],
-			[
-				'false',
-				'$strtotimeInvalid',
-			],
-			[
-				'int|false',
-				'$strtotimeUnknown',
-			],
-			[
-				'(int|false)',
-				'$strtotimeUnknown2',
-			],
-			[
-				'int|false',
-				'$strtotimeCrash',
-			],
 			[
 				'-1',
 				'$versionCompare1',

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -45,6 +45,7 @@ public function dataFileAsserts(): iterable
 		if (PHP_INT_SIZE === 8) {
 			yield from $this->gatherAssertTypes(__DIR__ . '/data/random-int.php');
 		}
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/strtotime-return-type-extensions.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/closure-return-type-extensions.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-key.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/intersection-static.php');

tests/PHPStan/Analyser/data/functions.php

@@ -6,12 +6,6 @@
 $microtimeDefault = microtime(null);
 $microtimeBenevolent = microtime($undefined);
 
-$strtotimeNow = strtotime('now');
-$strtotimeInvalid = strtotime('4 qm');
-$strtotimeUnknown = strtotime(doFoo() ? 'now': '4 qm');
-$strtotimeUnknown2 = strtotime($undefined);
-$strtotimeCrash = strtotime();
-
 $versionCompare1 = version_compare('7.0.0', '7.0.1');
 $versionCompare2 = version_compare('7.0.0', doFoo() ? '7.0.1' : '6.0.0');
 $versionCompare3 = version_compare(doFoo() ? '7.0.0' : '6.0.5', doBar() ? '7.0.1' : '6.0.0');

tests/PHPStan/Analyser/data/strtotime-return-type-extensions.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace ClosureReturnTypeExtensionsNamespace;
+
+use function PHPStan\Testing\assertType;
+
+$strtotimeNow = strtotime('now');
+assertType('int<1, max>', $strtotimeNow);
+
+$strtotimeInvalid = strtotime('4 qm');
+assertType('false', $strtotimeInvalid);
+
+$strtotimeUnknown = strtotime(rand(0, 1) === 0 ? 'now': '4 qm');
+assertType('int|false', $strtotimeUnknown);
+
+$strtotimeUnknown2 = strtotime($undefined);
+assertType('(int|false)', $strtotimeUnknown2);
+
+$strtotimeCrash = strtotime();
+assertType('int|false', $strtotimeCrash);
+
+$strtotimeWithBase = strtotime('+2 days', time());
+assertType('int', $strtotimeWithBase);
+
+$strtotimePositiveInt = strtotime('1990-01-01 12:00:00 UTC');
+assertType('int<1, max>', $strtotimePositiveInt);
+
+$strtotimeNegativeInt = strtotime('1969-12-31 12:00:00 UTC');
+assertType('int', $strtotimeNegativeInt);