Fix reportNestedTooWideType (improve UnionType::traverseSimultaneously())

Author: ondrejmirtes

src/Type/UnionType.php

@@ -1143,28 +1143,35 @@ public function traverse(callable $cb): Type
 
 public function traverseSimultaneously(Type $right, callable $cb): Type
 {
-$types = [];
+$rightTypes = TypeUtils::flattenTypes($right);
+$newTypes = [];
 $changed = false;
+foreach ($this->types as $innerType) {
+$candidates = [];
+foreach ($rightTypes as $i => $rightType) {
+if (!$innerType->isSuperTypeOf($rightType)->yes()) {
+continue;
+}
 
-if (!$right instanceof self) {
-return $this;
-}
+$candidates[] = $rightType;
+unset($rightTypes[$i]);
+}
 
-if (count($this->getTypes()) !== count($right->getTypes())) {
-return $this;
-}
+if (count($candidates) === 0) {
+$newTypes[] = $innerType;
+continue;
+}
 
-foreach ($this->getSortedTypes() as $i => $leftType) {
-$rightType = $right->getSortedTypes()[$i];
-$newType = $cb($leftType, $rightType);
-if ($leftType !== $newType) {
+$newType = $cb($innerType, TypeCombinator::union(...$candidates));
+if ($innerType !== $newType) {
 $changed = true;
 }
-$types[] = $newType;
+
+$newTypes[] = $newType;
 }
 
 if ($changed) {
-return TypeCombinator::union(...$types);
+return TypeCombinator::union(...$newTypes);
 }
 
 return $this;

tests/PHPStan/Rules/TooWideTypehints/TooWideMethodReturnTypehintRuleTest.php

@@ -295,6 +295,10 @@ public function testNestedTooWideType(): void
 28,
 'Offset 0 (int) does not accept type int|null.',
 ],
+[
+'Return type array<string, bool|int|string> of method NestedTooWideMethodReturnType\WebhookTest::dataTest() can be narrowed to array<string, int|string|true>.',
+115,
+],
 ]);
 }
 

tests/PHPStan/Rules/TooWideTypehints/data/nested-too-wide-method-return-type.php

@@ -105,3 +105,20 @@ public function doFoo(): array
 }
 
 }
+
+final class WebhookTest
+{
+
+/**
+ * @return array<string, int|string|bool>
+ */
+public function dataTest(int $remoteId, string $hookUrl): array
+{
+return [
+'id' => $remoteId,
+'url' => $hookUrl,
+'push_events' => true,
+];
+}
+
+}