Reuse owned feedback finalizers

2 files changed, 50 insertions, 1 deletions

diff --git a/lua/clever_f/feedback_service.lua b/lua/clever_f/feedback_service.lua
index 492eda6..0af482a 100644
--- a/lua/clever_f/feedback_service.lua
+++ b/lua/clever_f/feedback_service.lua
@@ -102,6 +102,7 @@ local function require_host(host)
     or type(host.remove_highlight) ~= "function"
     or type(host.read_buffer) ~= "function"
     or type(host.register_events) ~= "function"
+    or type(host.remove_event_registration) ~= "function"
     or type(host.supports_cursor_presentation) ~= "function"
     or type(host.suppress_cursor_presentation) ~= "function"
     or type(host.restore_cursor_presentation) ~= "function"
@@ -119,6 +120,7 @@ local function require_transitions(transitions, state)
     or type(transitions.AddTargetOverlay) ~= "function"
     or type(transitions.ClearTargetOverlays) ~= "function"
     or type(transitions.AddFinalizer) ~= "function"
+    or type(transitions.RemoveFinalizer) ~= "function"
   then
     fail("FeedbackService transitions must manage overlay resources", 3)
   end
@@ -151,6 +153,7 @@ function FeedbackService.new(options)
       options.state
     ),
     persistent_requests = {},
+    owned_finalizer = nil,
   }
   return service
 end
@@ -461,6 +464,15 @@ end
 
 local function register_finalizers(service, record)
   local buffer = record.host:read_buffer()
+  local owned = record.owned_finalizer
+  if owned ~= nil and owned.buffer == buffer then
+    return owned
+  end
+  if owned ~= nil then
+    record.host:remove_event_registration(owned.identity)
+    record.transitions:RemoveFinalizer(owned.identity, owned.buffer)
+  end
+
   local identity = record.host:register_events(
     M.FINALIZER_EVENTS,
     function(name, payload)
@@ -469,10 +481,12 @@ local function register_finalizers(service, record)
     { buffer = buffer }
   )
   record.transitions:AddFinalizer(identity, buffer)
-  return {
+  owned = {
     identity = identity,
     buffer = buffer,
   }
+  record.owned_finalizer = owned
+  return owned
 end
 
 function FeedbackService:request_persistent(specification)
diff --git a/tests/run.lua b/tests/run.lua
index 2da1855..062f9ec 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -6097,6 +6097,41 @@ test("Persistent creation registers current-buffer finalizers", function()
   truthy(registration.active)
 end)
 
+test("Persistent feedback owns one finalizer set", function()
+  local state, transitions = fresh_sequence_state()
+  local host = MemoryHost.new({ buffer_lines = { "aba" } })
+  local feedback = feedback_service.new({
+    host = host,
+    transitions = transitions,
+  })
+  local shared_target = target_plan.build(target("a"), matching_policy())
+  local movement = motion_plan.build(shared_target, "f")
+  local function create()
+    return feedback:request_persistent({
+      context = "n",
+      anchor = domain.Position.new(1, 1),
+      target_plan = shared_target,
+      motion_plan = movement,
+      window = "window-1",
+    })
+  end
+
+  local first = create()
+  local second = create()
+  same(first.finalizers.identity, second.finalizers.identity)
+  same(1, #state.finalizers)
+
+  host:set_buffer("buffer-2")
+  local third = create()
+  falsy(first.finalizers.identity == third.finalizers.identity)
+  same(1, #state.finalizers)
+  same(third.finalizers.identity, state.finalizers[1].identity)
+  same("buffer-2", state.finalizers[1].buffer)
+  local registrations = host:event_registrations()
+  falsy(registrations[first.finalizers.identity].active)
+  truthy(registrations[third.finalizers.identity].active)
+end)
+
 for _, item in ipairs(tests) do
   local ok, failure = xpcall(item.body, debug.traceback)
   if not ok then