Count uppercase smart-case folds

2 files changed, 35 insertions, 1 deletions

diff --git a/lua/clever_f/direct_preview_planner.lua b/lua/clever_f/direct_preview_planner.lua
index a034c3c..16808af 100644
--- a/lua/clever_f/direct_preview_planner.lua
+++ b/lua/clever_f/direct_preview_planner.lua
@@ -102,10 +102,26 @@ local function increment_counter(counters, character)
   return value
 end
 
+local function is_upper_ascii(character)
+  if type(character) ~= "string" or #character ~= 1 then
+    return false
+  end
+  local code = character:byte(1)
+  return code >= string.byte("A") and code <= string.byte("Z")
+end
+
 local function increment_smart_counters(counters, character)
-  return increment_counter(counters, character)
+  local exact_count = increment_counter(counters, character)
+  local lowercase_count
+  if is_upper_ascii(character) then
+    local lowercase = string.char(character:byte(1) + 32)
+    lowercase_count = increment_counter(counters, lowercase)
+  end
+  return exact_count, lowercase_count
 end
 
+M.is_upper_ascii = is_upper_ascii
+
 local function require_case_setting(settings, name)
   local value = settings[name]
   if value == nil then
diff --git a/tests/run.lua b/tests/run.lua
index ba6757f..4984fb6 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -4692,6 +4692,24 @@ test("Smart-case previews increment every exact character counter", function()
   same(domain.Position.new(1, 5), positions[2])
 end)
 
+test("Smart-case previews add ASCII uppercase to lowercase counters", function()
+  local planner = direct_preview_planner.new({ lowercase = string.lower })
+  local view = text_topology.new({ "xAa" }, "utf-8")
+  local positions = planner:plan(
+    view,
+    domain.Position.new(1, 1),
+    "f",
+    2,
+    { ignore_case = false, smart_case = true }
+  )
+
+  same(1, #positions)
+  same(domain.Position.new(1, 3), positions[1])
+  truthy(direct_preview_planner.is_upper_ascii("A"))
+  falsy(direct_preview_planner.is_upper_ascii("a"))
+  falsy(direct_preview_planner.is_upper_ascii("AA"))
+end)
+
 for _, item in ipairs(tests) do
   local ok, failure = xpcall(item.body, debug.traceback)
   if not ok then