Problem

The Following::follow() method and related follow() function have overly complex return type signatures that make the code harder to understand and use reliably.

Current Return Types

Activitypub\Collection\Following::follow() method:

• \WP_Error - when invalid actor or actor retrieval fails
• int|false - from add_to_outbox() when successfully adding follow activity
• \WP_Post - when user is already following the actor

Activitypub\follow() function:

• @return int|false|\WP_Post|\WP_Error The Outbox ID or false on failure, the Actor post or a WP_Error.

Referenced Discussion

This issue was raised in PR #2086: #2086 (comment)

@obenland suggested: "Would it be possible to limit it to two types?" to simplify the return type complexity.

Proposed Solution

Standardize the return types to a maximum of two types (e.g., int|\WP_Error or bool|\WP_Error) to improve:

• Code predictability
• Error handling consistency
• Developer experience when using these methods

Code References

• includes/functions.php:1556 - follow() function
• includes/collection/class-following.php - Following::follow() method
• includes/functions.php:1471 - add_to_outbox() function (returns int|false)

This refactoring would make the codebase more maintainable and reduce confusion about expected return types.