Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

`object|<Class>` docblocks in `DispatchTrait` break metadata warmup under symfony/type-info 7.4 (`Cannot create union with both "object" and class type`)

Closed Beginner friendly
#8,312 2 comments 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
1/5
Estimated time
Under an hour
Newbie friendliness
88/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Quiet
Tech stack
php, symfony
Domain
api, backend

Research direction

Start by inspecting src/Symfony/Messenger/DispatchTrait.php and src/Doctrine/Common/Messenger/DispatchTrait.php, then use the reported grep command to confirm both redundant docblocks. Run the standalone reproduction with Symfony TypeInfo 7.4; done means metadata extraction no longer raises the reported union-type exception.

Written by the indexing model from the issue text.

Description

API Platform version

4.3.13

PHP version

8.4

Description

api-platform/core 4.3 ships redundant union docblocks of the form
object|<Class> in its own source:

  • src/Symfony/Messenger/DispatchTrait.php:28 → @param object|Envelope $message
  • src/Doctrine/Common/Messenger/DispatchTrait.php:28 → @param object|Envelope $message

With symfony/type-info 7.4 installed, the PhpStanExtractor that API Platform
wires as api_platform.property_info.php_stan_extractor throws an Exception while building
the type graph whenever it parses such a docblock:

Symfony\Component\TypeInfo\Exception\InvalidArgumentException:
Cannot create union with both "object" and class type.
  at vendor/symfony/type-info/Type/UnionType.php:75

object|Envelope is redundant — object already subsumes every class type.
The legacy symfony/property-info Type model tolerated this; symfony/type-info
7.4 rejects it hard.

This regressed cache:clear / routing warmup on the Symfony 7.3 → 7.4 bump.

Relation to #8201 / #8206

PR #8206 (released in 4.3.10) isolated the framework property_info service
from API Platform's extractors via private api_platform.property_info.* tags +
a bridge compiler pass. That fixed the path where API Platform's PhpStanExtractor
leaked into the framework service (Sylius @template T of object crash).

It does not cover this case: API Platform's own PhpStanExtractor still
parses object|<Class> docblocks during metadata warmup and hits the same
type-info exception. The remaining 4.3 path is still affected.

How to reproduce

Minimal standalone reproduction (public packages only, no app kernel needed):
https://gist.github.com/schmunk42/3357f3d0fdffe11e977812900355cefd

composer install
php repro.php
PHP            : 8.4.22
api-platform/core: v4.3.13
symfony/type-info: v7.4.9
symfony/property-info: v7.4.8
------------------------------------------------------------
[KO]  Symfony\Component\TypeInfo\Exception\InvalidArgumentException: Cannot create union with both "object" and class type.
      thrown from: .../symfony/type-info/Type/UnionType.php:75

The gist invokes the exact extractor API Platform wires as
api_platform.property_info.php_stan_extractor directly
Title:


on a property whose
docblock mirrors the DispatchTrait shape (@var object|Envelope).

You can also confirm the offending docblocks directly:

grep -rn "object|Envelope" vendor/api-platform/core/src
# src/Doctrine/Common/Messenger/DispatchTrait.php:28
# src/Symfony/Messenger/DispatchTrait.php:28

Possible solution

Drop the redundant |Envelope from both DispatchTrait docblocks — the
method already declares object $message / : Envelope in the signature, so
the docblock carries no extra information:

-    /**
-     * @param object|Envelope $message
-     */
     private function dispatch(object $message): Envelope

(or @param object $message if a docblock is desired). This keeps the source
free of redundant unions that symfony/type-info 7.4 rejects.

Dominant language
PHP
Stars
2.6k
Forks
982
Avg merge
1d 19h
Merged PRs (30d)
67

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from api-platform/core

All issues in api-platform/core

Similar issues

More PHP issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.