feat: tiebreak config function (#1401)

Co-authored-by: Simon Hauser <Simon-Hauser@outlook.de>

lua/telescope/config.lua

@@ -153,6 +153,25 @@ append(
   - "ascending"]]
 )
 
+append(
+  "tiebreak",
+  function(current_entry, existing_entry, _)
+    return #current_entry.ordinal < #existing_entry.ordinal
+  end,
+  [[
+  A function that determines how to break a tie when two entries have
+  the same score.
+  Having a function that always returns false would keep the entries in
+  the order they are found, so existing_entry before current_entry.
+  Vice versa always returning true would place the current_entry
+  before the existing_entry.
+
+  Signature: function(current_entry, existing_entry, prompt) -> boolean
+
+  Default: function that breaks the tie based on the length of the
+           entry's ordinal]]
+)
+
 append(
   "selection_strategy",
   "reset",

lua/telescope/entry_manager.lua

@@ -105,7 +105,7 @@ function EntryManager:_append_container(picker, new_container, should_update)
   end
 end
 
-function EntryManager:add_entry(picker, score, entry)
+function EntryManager:add_entry(picker, score, entry, prompt)
   score = score or 0
 
   local max_res = self.max_results
@@ -137,7 +137,7 @@ function EntryManager:add_entry(picker, score, entry)
       return self:_insert_container_before(picker, index, node, new_container)
     end
 
-    if score < 1 and container[2] == score and #entry.ordinal < #container[1].ordinal then
+    if score < 1 and container[2] == score and picker.tiebreak(entry, container[1], prompt) then
       return self:_insert_container_before(picker, index, node, new_container)
     end
 

lua/telescope/pickers.lua

@@ -105,6 +105,7 @@ function Picker:new(opts)
 
     scroll_strategy = get_default(opts.scroll_strategy, config.values.scroll_strategy),
     sorting_strategy = get_default(opts.sorting_strategy, config.values.sorting_strategy),
+    tiebreak = get_default(opts.tiebreak, config.values.tiebreak),
     selection_strategy = get_default(opts.selection_strategy, config.values.selection_strategy),
 
     layout_strategy = layout_strategy,
@@ -1210,7 +1211,8 @@ function Picker:get_result_processor(find_id, prompt, status_updater)
   local count = 0
 
   local cb_add = function(score, entry)
-    self.manager:add_entry(self, score, entry)
+    -- may need the prompt for tiebreak
+    self.manager:add_entry(self, score, entry, prompt)
     status_updater { completed = false }
   end