Add DateInterval extension

conf/config.neon

@@ -1027,6 +1027,11 @@ services:
 		tags:
 			- phpstan.broker.dynamicFunctionReturnTypeExtension
 
+	-
+		class: PHPStan\Type\Php\DateIntervalConstructorThrowTypeExtension
+		tags:
+			- phpstan.dynamicStaticMethodThrowTypeExtension
+
 	-
 		class: PHPStan\Type\Php\DateTimeDynamicReturnTypeExtension
 		tags:

src/Type/Php/DateIntervalConstructorThrowTypeExtension.php

@@ -0,0 +1,44 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use DateInterval;
+use PhpParser\Node\Expr\StaticCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicStaticMethodThrowTypeExtension;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeUtils;
+
+class DateIntervalConstructorThrowTypeExtension implements DynamicStaticMethodThrowTypeExtension
+{
+
+	public function isStaticMethodSupported(MethodReflection $methodReflection): bool
+	{
+		return $methodReflection->getName() === '__construct' && $methodReflection->getDeclaringClass()->getName() === DateInterval::class;
+	}
+
+	public function getThrowTypeFromStaticMethodCall(MethodReflection $methodReflection, StaticCall $methodCall, Scope $scope): ?Type
+	{
+		if (count($methodCall->args) === 0) {
+			return $methodReflection->getThrowType();
+		}
+
+		$arg = $methodCall->args[0]->value;
+		$constantStrings = TypeUtils::getConstantStrings($scope->getType($arg));
+		if (count($constantStrings) === 0) {
+			return $methodReflection->getThrowType();
+		}
+
+		foreach ($constantStrings as $constantString) {
+			try {
+				new \DateInterval($constantString->getValue());
+			} catch (\Exception $e) { // phpcs:ignore
+				return $methodReflection->getThrowType();
+			}
+		}
+
+		return null;
+	}
+
+}

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php

@@ -59,6 +59,10 @@ public function testRule(): void
 				'Dead catch - Exception is never thrown in the try block.',
 				180,
 			],
+			[
+				'Dead catch - Exception is never thrown in the try block.',
+				212,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Exceptions/data/unthrown-exception.php

@@ -192,3 +192,35 @@ public function doBaz(string $s): void
 	}
 
 }
+
+class TestDateInterval
+{
+
+	public function doFoo(): void
+	{
+		try {
+			new \DateInterval('invalid format');
+		} catch (\Exception $e) {
+
+		}
+	}
+
+	public function doBar(): void
+	{
+		try {
+			new \DateInterval('P10D');
+		} catch (\Exception $e) {
+
+		}
+	}
+
+	public function doBaz(string $s): void
+	{
+		try {
+			new \DateInterval($s);
+		} catch (\Exception $e) {
+
+		}
+	}
+
+}