Fix route:cache failing on signal webhook routes (Serialization of 'ReflectionMethod' is not allowed)

[jakobkollerup]

Problem

With any workflow that has a #[SignalMethod] + #[Webhook] method registered via Webhooks::routes(), php artisan route:cache fails:

Exception: Serialization of 'ReflectionMethod' is not allowed

Laravel serializes closure-based routes with SerializableClosure (all supported versions, 9 through 13, do this in Route::prepareForSerialization()), which serializes the closure's captured variables. The signal webhook closure captures the ReflectionMethod instance:

static function (Request $request, $workflowId) use ($workflow, $method) {

and PHP refuses to serialize reflection objects. Since route:cache/optimize runs in most production deploys, adding the first #[Webhook] signal method breaks deployment. The start webhook closure is fine — it only captures the class-name string.

Fix

Capture the method name (a string) instead of the ReflectionMethod; the closure only ever used $method->getName().

Test

testWebhookRoutesCanBeSerializedForRouteCaching mirrors what route:cache does (prepareForSerialization() + serialize() on each registered webhook route). It fails on master with the exception above and passes with this change.

Note: the v2 branch has the same capture in its src/Webhooks.php, so this is worth porting there too.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (530c376) to head (77d32d4).

Additional details and impacted files

@@             Coverage Diff             @@
##              master      #398   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity       666       666           
===========================================
  Files             63        63           
  Lines           2266      2267    +1     
===========================================
+ Hits            2266      2267    +1     

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[Copilot]

Pull request overview

This PR fixes Laravel route:cache failures caused by webhook signal routes capturing a ReflectionMethod inside a closure (which is not serializable). It updates webhook route registration to capture only the signal method name (string) and adds a unit test that mirrors Laravel’s route caching serialization behavior.

Changes:

• Update signal webhook route closure to capture $signalMethod (string) instead of a ReflectionMethod instance.
• Invoke the signal method via the captured name to avoid serializing reflection objects during route:cache.
• Add a unit test that calls prepareForSerialization() + serialize() on workflow webhook routes to ensure route caching compatibility.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Webhooks.php	Avoids capturing ReflectionMethod in signal webhook route closures by capturing the method name string instead.
tests/Unit/WebhooksTest.php	Adds coverage ensuring workflow webhook routes can be prepared and serialized like php artisan route:cache does.

[rmcdaniel]

Confirmed this also affected the v2 branch. The v2 fix is now released in durable-workflow/workflow:2.0.0-alpha.291 from commit 518a27492d38bd92bca3e2bb91b9ccf82da9589b. Thanks for flagging the cross-branch impact.