fix: refuse an unknown operation in unschedule

schedule already raised UnknownMessage for an operation the actor does
not declare, because OperationDispatcher checks it. unschedule and
unschedule_all took any symbol, composed a name from it, and deleted
nothing. A typo cancelled quietly and left a recurring reminder running,
which is the failure this feature exists to prevent.

Both now check the operation against the declared messages and raise the
same error schedule raises. A handle skips the check, because schedule
validated the operation that produced it.

Author: cardmagic

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- Refuse an unknown operation in `unschedule` and `unschedule_all`. `schedule`
+  already raised `UnknownMessage` for one, so a typo cancelled nothing quietly
+  and left a recurring reminder running.
 - Add reminder cancellation. `unschedule` removes one reminder by operation and
   optional key, or by the handle `schedule` now returns. `unschedule_all`
   removes every key of one operation. Both stage an intent, so a cancel commits

lib/solid_objects/actor.rb

@@ -279,12 +279,13 @@ def schedule(at:, every: nil, missed: :latest, key: nil)
     def unschedule(operation_or_handle, key: nil)
       return unschedule_name(handle_name(operation_or_handle, key:)) if operation_or_handle.is_a?(Hash)
 
+      validated_reminder_operation(operation_or_handle)
       unschedule_name(reminder_name(operation: operation_or_handle, key: validated_reminder_key(key)))
     end
 
     # @rbs (Symbol | String) -> nil
     def unschedule_all(operation)
-      reminder_intents << UnscheduleAllIntent.new(operation: operation.to_s)
+      reminder_intents << UnscheduleAllIntent.new(operation: validated_reminder_operation(operation))
       nil
     end
 
@@ -303,6 +304,14 @@ def reminders(operation)
 
     attr_reader :instance_id
 
+    # @rbs (Symbol | String) -> String
+    def validated_reminder_operation(operation)
+      name = operation.to_s
+      return name if self.class.definition.messages.key?(name.to_sym)
+
+      raise UnknownMessage, "unknown message #{name.inspect} for #{self.class.actor_type}"
+    end
+
     # @rbs (String) -> nil
     def unschedule_name(name)
       reminder_intents << UnscheduleIntent.new(name:)

sig/generated/lib/solid_objects/actor.rbs

@@ -266,6 +266,9 @@ module SolidObjects
 
     attr_reader instance_id: untyped
 
+    # @rbs (Symbol | String) -> String
+    def validated_reminder_operation: (Symbol | String) -> String
+
     # @rbs (String) -> nil
     def unschedule_name: (String) -> nil
 

test/integration/reminder_cancellation_test.rb

@@ -38,6 +38,14 @@ def convert_then_raise
       raise "turn failed"
     end
 
+    def cancel_unknown
+      unschedule(:no_such_operation)
+    end
+
+    def cancel_all_unknown
+      unschedule_all(:no_such_operation)
+    end
+
     def convert_with_bad_handle
       unschedule({ "not_a_reminder" => "x" })
     end
@@ -275,6 +283,21 @@ def state_of(actor_type)
     assert_empty reminders_for("cancel-trial")
   end
 
+  test "an unknown operation is refused rather than cancelling nothing" do
+    SolidObjects.configuration.max_attempts = 1
+    reference = TrialActor.ref("alice")
+    reference.async.start_trial
+    drain
+    reference.async.cancel_unknown
+    reference.async.cancel_all_unknown
+    drain
+
+    assert_equal 2, SolidObjects::DeadLetter.where(actor_type: "cancel-trial").count
+    assert_equal [ "SolidObjects::UnknownMessage" ],
+      SolidObjects::DeadLetter.where(actor_type: "cancel-trial").distinct.pluck(:exception_class)
+    assert_equal 1, reminders_for("cancel-trial").count
+  end
+
   test "a malformed handle is rejected" do
     SolidObjects.configuration.max_attempts = 1
     TrialActor.ref("alice").async.convert_with_bad_handle