Strip down data of a record context marked by SensitiveParameter

[theofidry]

Context

When logging, values passed as part of the record context may contain PHP objects that are normalized by a Monolog\Formatter\FormatterInterface:

$logger->log(
  'My message',
  context: ['message' => $message, ...$additionalContext],
);

Problem

Consider an object like this:

final readonly class UpdateUser {
  function __construct(
    public string $id,``
    #[SensitiveParameter]
    public string $mySecretUrl,
  ) {}
}

Since PHP 8.2, #[SensitiveParameter] prevents UpdateUser::$mySecretUrl from appearing in stack traces. However, when such an object is passed as part of a log record context, this attribute is not respected and the sensitive value is still written to the logs.

Proposal

Formatters could leverage #[SensitiveParameter] to automatically redact sensitive properties during normalization.

Based on symfony/symfony#46183, this behaviour may not always be desired, so it could be implemented behind a configuration flag. That said, I would argue that redacting by default is the safer choice—frameworks like Symfony could then disable it in dev/debug mode if needed.

Additionally, since users often implement custom formatters, it would be helpful to expose this functionality in a reusable way.