Add non regression tests

Author: VincentLanglet

tests/PHPStan/Analyser/AnalyserIntegrationTest.php

@@ -601,6 +601,14 @@ public function testBug6649(): void
 		$this->assertNoErrors($errors);
 	}
 
+	public function testBug6842(): void
+	{
+		$errors = $this->runAnalyse(__DIR__ . '/data/bug-6842.php');
+		$this->assertCount(1, $errors);
+		$this->assertSame('Generator expects value type T of DateTimeInterface, DateTime|DateTimeImmutable|T of DateTimeInterface given.', $errors[0]->getMessage());
+		$this->assertSame(28, $errors[0]->getLine());
+	}
+
 	/**
 	 * @param string[]|null $allAnalysedFiles
 	 * @return Error[]

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -815,6 +815,7 @@ public function dataFileAsserts(): iterable
 			yield from $this->gatherAssertTypes(__DIR__ . '/data/value-of-enum.php');
 		}
 
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6576.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6584.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6439.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6748.php');

tests/PHPStan/Analyser/data/bug-6576.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Bug6576;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param array<int|string, mixed> $arr
+ */
+function alreadyWorks(array $arr): void {
+	foreach ($arr as $key => $value) {
+		assertType('int|string', $key);
+	}
+}
+
+/**
+ * @template ArrType of array<int|string, mixed>
+ *
+ * @param ArrType $arr
+ */
+function shouldWork(array $arr): void {
+	foreach ($arr as $key => $value) {
+		assertType('int|string', $key);
+	}
+}

tests/PHPStan/Analyser/data/bug-6842.php

@@ -0,0 +1,45 @@
+<?php declare(strict_types = 1);
+
+namespace Bug6842;
+
+class HelloWorld
+{
+	/**
+	 * @template T of \DateTimeInterface|\DateTime|\DateTimeImmutable
+	 *
+	 * @param T $startDate
+	 * @param T $endDate
+	 *
+	 * @return \Iterator<T>
+	 */
+	public function getScheduledEvents(
+		\DateTimeInterface $startDate,
+		\DateTimeInterface $endDate
+	): \Iterator {
+		$interval = \DateInterval::createFromDateString('1 day');
+
+		/** @var \Iterator<T> $datePeriod */
+		$datePeriod = new \DatePeriod($startDate, $interval, $endDate);
+
+		foreach ($datePeriod as $dateTime) {
+			$scheduledEvent = $this->createScheduledEventFromSchedule($dateTime);
+
+			if ($scheduledEvent >= $startDate) {
+				yield $scheduledEvent;
+			}
+		}
+	}
+
+	/**
+	 * @template T of \DateTimeInterface
+	 *
+	 * @param T|\DateTime|\DateTimeImmutable $dateTime
+	 *
+	 * @return T|\DateTime|\DateTimeImmutable
+	 */
+	protected function createScheduledEventFromSchedule(
+		\DateTimeInterface $dateTime
+	): \DateTimeInterface {
+		return $dateTime;
+	}
+}