feat(filesystem): add a fzf based fuzzy search algorithm, with sorting by score (#721)

Author: pysan3

README.md

@@ -284,6 +284,8 @@ use {
               ["H"] = "toggle_hidden",
               ["/"] = "fuzzy_finder",
               ["D"] = "fuzzy_finder_directory",
+              ["#"] = "fuzzy_sorter", -- fuzzy sorting using the fzy algorithm
+              -- ["D"] = "fuzzy_sorter_directory",
               ["f"] = "filter_on_submit",
               ["<c-x>"] = "clear_filter",
               ["[g"] = "prev_git_modified",

doc/neo-tree.txt

@@ -325,6 +325,14 @@ D = fuzzy_finder_directory: Like fuzzy_finder above, but only shows directories.
                             search and set the focus on that directory.
                             Requires `fd` or `find` to be installed~
 
+# = fuzzy_sorter:           Sort the tree recursively based on fzy algorithm,
+                            showing top score files. Space separated keywords
+                            are treated as `and` which will be useful to narrow
+                            down as you type. The file list is taken from fd
+                            and other programs mentioned in `fuzzy_finder`.
+                            `fuzzy_sorter_directory` can be used to show list
+                            of directories instead.
+
 f = filter_on_submit:       Same as above, but does not search until you hit
                             enter. Useful if filter_as_you_type is too slow.
                             Also useful if you want to leave the tree

lua/neo-tree/defaults.lua

@@ -359,6 +359,8 @@ local config = {
         ["/"] = "fuzzy_finder",
         ["D"] = "fuzzy_finder_directory",
         --["/"] = "filter_as_you_type", -- this was the default until v1.28
+        ["#"] = "fuzzy_sorter", -- fuzzy sorting using the fzy algorithm
+        -- ["D"] = "fuzzy_sorter_directory",
         ["f"] = "filter_on_submit",
         ["<C-x>"] = "clear_filter",
         ["<bs>"] = "navigate_up",

lua/neo-tree/sources/filesystem/commands.lua

@@ -94,6 +94,16 @@ M.fuzzy_finder_directory = function(state)
   filter.show_filter(state, true, "directory")
 end
 
+---Shows the filter input in fuzzy sorter
+M.fuzzy_sorter = function(state)
+  filter.show_filter(state, true, true, true)
+end
+
+---Shows the filter input in fuzzy sorter with only directories
+M.fuzzy_sorter_directory = function(state)
+  filter.show_filter(state, true, "directory", true)
+end
+
 ---Navigate up one level.
 M.navigate_up = function(state)
   local parent_path, _ = utils.split_path(state.path)

lua/neo-tree/sources/filesystem/init.lua

@@ -185,6 +185,10 @@ end
 M.reset_search = function(state, refresh, open_current_node)
   log.trace("reset_search")
   state.fuzzy_finder_mode = nil
+  state.use_fzy = nil
+  state.fzy_sort_result_scores = nil
+  state.fzy_sort_file_list_cache = nil
+  state.sort_function_override = nil
   if refresh == nil then
     refresh = true
   end

lua/neo-tree/sources/filesystem/lib/filter.lua

@@ -14,7 +14,7 @@ local renderer = require("neo-tree.ui.renderer")
 
 local M = {}
 
-M.show_filter = function(state, search_as_you_type, fuzzy_finder_mode)
+M.show_filter = function(state, search_as_you_type, fuzzy_finder_mode, use_fzy)
   local popup_options
   local winid = vim.api.nvim_get_current_win()
   local height = vim.api.nvim_win_get_height(winid)
@@ -55,6 +55,29 @@ M.show_filter = function(state, search_as_you_type, fuzzy_finder_mode)
     })
   end
 
+  local set_sort_by_score = function()
+    state.sort_function_override = function(a, b)
+      -- `state.fzy_sort_result_scores` should be defined in
+      -- `sources.filesystem.lib.filter_external.fzy_sort_files`
+      local result_scores = state.fzy_sort_result_scores or { foo = 0, baz = 0 }
+      local a_score = result_scores[a.path]
+      local b_score = result_scores[b.path]
+      if a_score == nil or b_score == nil then
+        log.debug(string.format([[Fzy: failed to compare %s: %s, %s: %s]], a.path, a_score, b.path, b_score))
+        local config = require("neo-tree").config
+        if config.sort_function ~= nil then
+          return config.sort_function(a, b)
+        end
+        return nil
+      end
+      return a_score > b_score
+    end
+  end
+  if use_fzy then
+    set_sort_by_score()
+    state.use_fzy = true
+  end
+
   local select_first_file = function()
     local is_file = function(node)
       return node.type == "file"