fix: use "" as flag to remove default mappings (#1011)

README.md

@@ -228,7 +228,7 @@ require'nvim-tree'.setup {
 The `list` option in `view.mappings.list` is a table of
 ```lua
 -- key can be either a string or a table of string (lhs)
--- action is the name of the action
+-- action is the name of the action, set to `""` to remove default action
 -- action_cb is the function that will be called, it receives the node as a parameter. Optional for default actions
 -- mode is normal by default
 
@@ -242,6 +242,7 @@ local list = {
   { key = {"<CR>", "o" }, action = "edit", mode = "n"},
   { key = "p", action = "print_path", action_cb = print_node_path },
   { key = "s", cb = tree_cb("vsplit") }, --tree_cb and the cb property are deprecated
+  { key = "<2-RightMouse>", action = "" }, -- will remove default cd action
 }
 ```
 

doc/nvim-tree-lua.txt

@@ -641,7 +641,7 @@ Defaults to:
 The `list` option in `view.mappings.list` is a table of
 
 - key can be either a string or a table of string (lhs)
-- action is the name of the action, set to nil to unmap default actions
+- action is the name of the action, set to `""` to remove default action
 - action_cb is the function that will be called, it receives the node as a parameter. Optional for default actions
 - mode is normal by default
 >
@@ -656,7 +656,7 @@ The `list` option in `view.mappings.list` is a table of
       { key = {"<CR>", "o" }, action = "edit", mode = "n"},
       { key = "p", action = "print_path", action_cb = print_node_path },
       { key = "s", cb = tree_cb("vsplit") }, --tree_cb and the cb property are deprecated
-      { key = "<2-RightMouse>", action = nil },
+      { key = "<2-RightMouse>", action = "" }, -- will remove default cd action
     }
 
 

lua/nvim-tree/actions/init.lua

@@ -2,6 +2,7 @@ local a = vim.api
 
 local lib = require'nvim-tree.lib'
 local view = require'nvim-tree.view'
+local util = require'nvim-tree.utils'
 local nvim_tree_callback = require'nvim-tree.config'.nvim_tree_callback
 
 local M = {
@@ -126,24 +127,34 @@ local function merge_mappings(user_mappings)
     return M.mappings
   end
 
+  local function is_empty(s)
+    return s == ''
+  end
+
   local user_keys = {}
   local removed_keys = {}
+  -- remove default mappings if action is a empty string
   for _, map in pairs(user_mappings) do
     if type(map.key) == "table" then
       for _, key in pairs(map.key) do
         table.insert(user_keys, key)
-        if not map.action then
+        if is_empty(map.action) then
           table.insert(removed_keys, key)
         end
       end
     else
       table.insert(user_keys, map.key)
-      if not map.action then
+      if is_empty(map.action) then
         table.insert(removed_keys, map.key)
       end
     end
+
     if map.action and type(map.action_cb) == "function" then
-      M.custom_keypress_funcs[map.action] = map.action_cb
+      if not is_empty(map.action) then
+        M.custom_keypress_funcs[map.action] = map.action_cb
+      else
+        util.warn("action can't be empty if action_cb provided")
+    end
     end
   end
 
@@ -163,7 +174,7 @@ local function merge_mappings(user_mappings)
   end, M.mappings)
 
   local user_map = vim.tbl_filter(function(map)
-    return map.action
+    return not is_empty(map.action)
   end, user_mappings)
 
   return vim.fn.extend(default_map, user_map)