Add test

Author: VincentLanglet

tests/PHPStan/Analyser/nsrt/bug-14203.php

@@ -0,0 +1,90 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug14203;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @template TKey of array-key
+ * @template TValue
+ */
+class Collection
+{
+    /**
+     * Create a new collection.
+     *
+     * @param  array<TKey, TValue>  $items
+     */
+    final public function __construct(protected $items = [])
+    {
+    }
+
+    /**
+	 * @template TMapValue
+     *
+     * @param  callable(TValue, TKey): TMapValue  $callback
+     * @return static<TKey, TMapValue>
+     */
+    public function map(callable $callback)
+    {
+        $newItems = [];
+
+		foreach ($this->items as $key => $value) {
+			$newItems[$key] = $callback($value, $key);
+		}
+
+		return new static($newItems);
+    }
+}
+
+class SpecificA {
+    public function __construct(
+		public readonly int $valueA,
+		public readonly string $someSharedValue,
+	) {}
+}
+
+class SpecificB {
+    public function __construct(
+		public readonly int $valueB,
+		public readonly string $someSharedValue,
+	) {}
+}
+
+class MyDTO {
+    public function __construct(
+		public readonly string $thatSharedValue,
+	) {}
+}
+
+function works(): void {
+    $myCollection = new Collection([new SpecificA(1, 'A'), new SpecificB(2, 'B')]);
+
+	$result = $myCollection->map(static fn (SpecificA|SpecificB $specific): MyDTO => new MyDTO($specific->someSharedValue));
+	assertType('Bug14203\Collection<int, Bug14203\MyDTO>', $result);
+}
+
+/**
+ * @return Collection<int, SpecificA>
+ */
+function getA(): Collection {
+	return new Collection([new SpecificA(1, 'A')]);
+}
+
+/**
+ * @return Collection<int, SpecificB>
+ */
+function getB(): Collection {
+	return new Collection([new SpecificB(2, 'B')]);
+}
+
+function breaks(): void {
+    $myCollection = random_int(0, 1) === 0
+		? getA()
+		: getB();
+
+	$result = $myCollection->map(static fn (SpecificA|SpecificB $specific): MyDTO => new MyDTO($specific->someSharedValue));
+	assertType('Bug14203\Collection<int, Bug14203\MyDTO>', $result);
+}