Preserve origins before any match

2 files changed, 55 insertions, 7 deletions

diff --git a/lua/clever_f/destination_engine.lua b/lua/clever_f/destination_engine.lua
index 027dd2a..53cb654 100644
--- a/lua/clever_f/destination_engine.lua
+++ b/lua/clever_f/destination_engine.lua
@@ -147,6 +147,16 @@ local function till_equality_allowed(request, successful_steps)
   return request.first_move and successful_steps == 0
 end
 
+local function boundary_outcome(request, endpoint, successful_steps)
+  if successful_steps > 0 then
+    return domain.SearchOutcome.boundary_after_partial(
+      endpoint,
+      successful_steps
+    )
+  end
+  return domain.SearchOutcome.boundary_before_any(request.origin)
+end
+
 function DestinationEngine:calculate(view, origin, plan, count, first_move)
   local request = calculation_inputs(view, origin, plan, count, first_move)
   local current_origin = request.origin
@@ -168,13 +178,7 @@ function DestinationEngine:calculate(view, origin, plan, count, first_move)
   if successful_steps == request.count.value then
     return domain.SearchOutcome.complete(current_origin, successful_steps)
   end
-  if successful_steps > 0 then
-    return domain.SearchOutcome.boundary_after_partial(
-      current_origin,
-      successful_steps
-    )
-  end
-  return domain.SearchOutcome.boundary_before_any(request.origin)
+  return boundary_outcome(request, current_origin, successful_steps)
 end
 
 function M.new()
diff --git a/tests/run.lua b/tests/run.lua
index eac53bf..7431de5 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -2839,6 +2839,50 @@ test("Partial outcomes retain the last intermediate destination", function()
   same(2, till_partial.successful_steps)
 end)
 
+test("Boundary-before-any outcomes preserve the original position", function()
+  local engine = destination_engine.new()
+  local view = text_topology.new({ "", "abc" }, "utf-8")
+  local origin = domain.Position.new(1, 1)
+  local missing = motion_plan.build(
+    target_plan.build(target("z"), matching_policy()),
+    "f",
+    "buffer"
+  )
+  local missing_outcome = engine:calculate(view, origin, missing, 4, true)
+  same(domain.SearchStatus.BOUNDARY_BEFORE_ANY, missing_outcome.status)
+  same(origin, missing_outcome.endpoint)
+  same(0, missing_outcome.successful_steps)
+
+  local adjacent_view = text_topology.new({ "ab" }, "utf-8")
+  local adjacent_origin = domain.Position.new(1, 1)
+  local repeated_till = motion_plan.build(
+    target_plan.build(target("b"), matching_policy()),
+    "t"
+  )
+  local adjacent_outcome = engine:calculate(
+    adjacent_view,
+    adjacent_origin,
+    repeated_till,
+    1,
+    false
+  )
+  same(domain.SearchStatus.BOUNDARY_BEFORE_ANY, adjacent_outcome.status)
+  same(adjacent_origin, adjacent_outcome.endpoint)
+  same(0, adjacent_outcome.successful_steps)
+
+  local all_empty = text_topology.new({ "", "" }, "utf-8")
+  local empty_origin = domain.Position.new(2, 1)
+  local empty_outcome = engine:calculate(
+    all_empty,
+    empty_origin,
+    missing,
+    1,
+    true
+  )
+  same(domain.SearchStatus.BOUNDARY_BEFORE_ANY, empty_outcome.status)
+  same(empty_origin, empty_outcome.endpoint)
+end)
+
 for _, item in ipairs(tests) do
   local ok, failure = xpcall(item.body, debug.traceback)
   if not ok then