Report invalid DateInterval constructor arguments at analysis time (#5587)

Co-authored-by: staabm <120441+staabm@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Markus Staab <maggus.staab@googlemail.com>

Author: 3 people

conf/bleedingEdge.neon

@@ -16,3 +16,4 @@ parameters:
 		reportNestedTooWideType: false # tmp
 		assignToByRefForeachExpr: true
 		curlSetOptArrayTypes: true
+		checkDateIntervalConstructor: true

conf/config.level5.neon

@@ -10,6 +10,8 @@ conditionalTags:
 		phpstan.rules.rule: %featureToggles.checkParameterCastableToNumberFunctions%
 	PHPStan\Rules\Functions\PrintfParameterTypeRule:
 		phpstan.rules.rule: %featureToggles.checkPrintfParameterTypes%
+	PHPStan\Rules\DateIntervalInstantiationRule:
+		phpstan.rules.rule: %featureToggles.checkDateIntervalConstructor%
 
 autowiredAttributeServices:
 	# registers rules with #[RegisteredRule] attribute
@@ -22,3 +24,5 @@ services:
 		class: PHPStan\Rules\Functions\PrintfParameterTypeRule
 		arguments:
 			checkStrictPrintfPlaceholderTypes: %checkStrictPrintfPlaceholderTypes%
+	-
+		class: PHPStan\Rules\DateIntervalInstantiationRule

conf/config.neon

@@ -43,6 +43,7 @@ parameters:
 		reportNestedTooWideType: false
 		assignToByRefForeachExpr: false
 		curlSetOptArrayTypes: false
+		checkDateIntervalConstructor: false
 	fileExtensions:
 		- php
 	checkAdvancedIsset: false

conf/parametersSchema.neon

@@ -45,6 +45,7 @@ parametersSchema:
 		reportNestedTooWideType: bool()
 		assignToByRefForeachExpr: bool()
 		curlSetOptArrayTypes: bool()
+		checkDateIntervalConstructor: bool()
 	])
 	fileExtensions: listOf(string())
 	checkAdvancedIsset: bool()

src/Rules/DateIntervalInstantiationRule.php

@@ -0,0 +1,60 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules;
+
+use DateInterval;
+use PhpParser\Node;
+use PhpParser\Node\Expr\New_;
+use PHPStan\Analyser\Scope;
+use Throwable;
+use function count;
+use function sprintf;
+use function strtolower;
+
+/**
+ * @implements Rule<Node\Expr\New_>
+ */
+final class DateIntervalInstantiationRule implements Rule
+{
+
+	public function getNodeType(): string
+	{
+		return New_::class;
+	}
+
+	/**
+	 * @param New_ $node
+	 */
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (!$node->class instanceof Node\Name) {
+			return [];
+		}
+
+		if (
+			count($node->getArgs()) === 0
+			|| strtolower((string) $node->class) !== 'dateinterval'
+		) {
+			return [];
+		}
+
+		$arg = $scope->getType($node->getArgs()[0]->value);
+		$errors = [];
+
+		foreach ($arg->getConstantStrings() as $constantString) {
+			$dateIntervalString = $constantString->getValue();
+			try {
+				new DateInterval($dateIntervalString);
+			} catch (Throwable $e) {
+				$errors[] = RuleErrorBuilder::message(sprintf(
+					'Instantiating DateInterval with %s produces an error: %s',
+					$dateIntervalString,
+					$e->getMessage(),
+				))->identifier('new.dateInterval')->build();
+			}
+		}
+
+		return $errors;
+	}
+
+}

tests/PHPStan/Rules/DateIntervalInstantiationRuleTest.php

@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules;
+
+use PHPStan\Testing\RuleTestCase;
+use const PHP_VERSION_ID;
+
+/**
+ * @extends RuleTestCase<DateIntervalInstantiationRule>
+ */
+class DateIntervalInstantiationRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new DateIntervalInstantiationRule();
+	}
+
+	public function test(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$prefix = 'DateInterval::__construct(): ';
+		} else {
+			$prefix = '';
+		}
+
+		$this->analyse(
+			[__DIR__ . '/data/date-interval-instantiation.php'],
+			[
+				[
+					'Instantiating DateInterval with 1M produces an error: ' . $prefix . 'Unknown or bad format (1M)',
+					5,
+				],
+				[
+					'Instantiating DateInterval with asdfasdf produces an error: ' . $prefix . 'Unknown or bad format (asdfasdf)',
+					18,
+				],
+				[
+					'Instantiating DateInterval with  produces an error: ' . $prefix . 'Unknown or bad format ()',
+					21,
+				],
+				[
+					'Instantiating DateInterval with 1M produces an error: ' . $prefix . 'Unknown or bad format (1M)',
+					30,
+				],
+				[
+					'Instantiating DateInterval with invalid produces an error: ' . $prefix . 'Unknown or bad format (invalid)',
+					37,
+				],
+			],
+		);
+	}
+
+}

tests/PHPStan/Rules/data/date-interval-instantiation.php

@@ -0,0 +1,38 @@
+<?php
+namespace DateIntervalInstantiation;
+
+// invalid - missing P prefix
+new \DateInterval('1M');
+
+// valid durations
+new \DateInterval('P1Y');
+new \DateInterval('P1M');
+new \DateInterval('P1D');
+new \DateInterval('PT1H');
+new \DateInterval('PT1M');
+new \DateInterval('PT1S');
+new \DateInterval('P1Y2M3DT4H5M6S');
+new \DateInterval('P7D');
+
+// invalid
+new \DateInterval('asdfasdf');
+
+// empty string is invalid
+new \DateInterval('');
+
+// non-constant string - should not report
+function foo(string $duration): void {
+	new \DateInterval($duration);
+}
+
+// constant string via variable
+$test = '1M';
+new \DateInterval($test);
+
+/**
+ * @param 'invalid' $duration2
+ */
+function bar(string $duration, string $duration2): void {
+	new \DateInterval($duration);
+	new \DateInterval($duration2);
+}