Skip to content

Improve TypeCombinator::addNull #6493

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
VincentLanglet merged 1 commit into from
Sep 21, 2026
+15 −4
Merged

Improve TypeCombinator::addNull #6493

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 5 additions & 4 deletions src/Type/TypeCombinator.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -80,10 +80,11 @@ public static function clearCache(): void

public static function addNull(Type $type): Type
{
$nullType = new NullType();

if ($nullType->isSuperTypeOf($type)->no()) {
return self::union($type, $nullType);
// asking the type itself is both cheaper than NullType::isSuperTypeOf()
// (UnionType memoizes isNull(), isSubTypeOf() recomputes) and right for
// `never`, of which null is a supertype without never containing it.
if ($type->isNull()->no()) {
return self::union($type, new NullType());
}

return $type;
Expand Down
10 changes: 10 additions & 0 deletions tests/PHPStan/Type/TypeCombinatorTest.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,16 @@ public static function dataAddNull(): array
NullType::class,
'null',
],
[
new NeverType(),
NullType::class,
'null',
],
[
new NeverType(true),
NullType::class,
'null',
],
[
new VoidType(),
UnionType::class,
Expand Down
Loading