Convert setExistingOffsetValueType unit tests to NSRT tests

Replace unit tests in ArrayTypeTest with an NSRT test in bug-13637.php
that covers the maybe-array item type scenario (union with non-array
skips recursive path) alongside the existing deep nesting tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/Analyser/nsrt/bug-13637.php

@@ -95,6 +95,24 @@ function sixLevelsDeep() : array {
 	return $final;
 }
 
+/** Tests that maybe-array item type (union with non-array) skips the recursive path */
+function maybeArrayItemType(bool $flag): void {
+	$final = [];
+
+	for ($i = 0; $i < 5; $i++) {
+		$j = $i * 2;
+		$k = $j + 1;
+		if ($flag) {
+			$final[$i][$j][$k]['abc'] = $i;
+			$final[$i][$j][$k]['def'] = $i;
+		} else {
+			$final[$i] = $i;
+		}
+	}
+
+	assertType("non-empty-array<int<0, 4>, non-empty-array<int<0, 8>, non-empty-array<int<1, 9>, array{abc: int<0, 4>, def: int<0, 4>}>>|int<0, 4>>", $final);
+}
+
 /**
 * @return array<int, array<int, array{abc: int, def: int, ghi: int}>>
 */

tests/PHPStan/Type/ArrayTypeTest.php

@@ -301,86 +301,6 @@ public function testHasOffsetValueType(
 		);
 	}
 
-	public static function dataSetExistingOffsetValueType(): array
-	{
-		return [
-			'maybe array item type falls through to union' => [
-				// array<int, int|array<int, array<int, array{abc: int}>>>
-				new ArrayType(
-					new IntegerType(),
-					new UnionType([
-						new IntegerType(),
-						new ArrayType(
-							new IntegerType(),
-							new ArrayType(
-								new IntegerType(),
-								new ConstantArrayType(
-									[new ConstantStringType('abc')],
-									[new IntegerType()],
-								),
-							),
-						),
-					]),
-				),
-				new IntegerType(),
-				new ArrayType(
-					new IntegerType(),
-					new ArrayType(
-						new IntegerType(),
-						new ConstantArrayType(
-							[new ConstantStringType('def')],
-							[new IntegerType()],
-						),
-					),
-				),
-				'array<int, array<int, array<int, array{abc: int}|array{def: int}>>|int>',
-			],
-			'definite array item type uses recursive path' => [
-				// array<int, array<int, array<int, array{abc: int}>>>
-				new ArrayType(
-					new IntegerType(),
-					new ArrayType(
-						new IntegerType(),
-						new ArrayType(
-							new IntegerType(),
-							new ConstantArrayType(
-								[new ConstantStringType('abc')],
-								[new IntegerType()],
-							),
-						),
-					),
-				),
-				new IntegerType(),
-				new ArrayType(
-					new IntegerType(),
-					new ArrayType(
-						new IntegerType(),
-						new ConstantArrayType(
-							[new ConstantStringType('def')],
-							[new IntegerType()],
-						),
-					),
-				),
-				'array<int, array<int, array<int, array{abc: int, def: int}>>>',
-			],
-		];
-	}
-
-	#[DataProvider('dataSetExistingOffsetValueType')]
-	public function testSetExistingOffsetValueType(
-		ArrayType $type,
-		Type $offsetType,
-		Type $valueType,
-		string $expectedType,
-	): void
-	{
-		$actualResult = $type->setExistingOffsetValueType($offsetType, $valueType);
-		$this->assertSame(
-			$expectedType,
-			$actualResult->describe(VerbosityLevel::precise()),
-		);
-	}
-
 	public static function dataSpliceArray(): array
 	{
 		return [