feat(api): add api.config.mappings.get_keymap and get_keymap_default (#2056)

* feat(api): add api.config.mappings.get_keymap and get_keymap_default

* feat(api): add api.config.mappings.get_keymap and get_keymap_default

doc/nvim-tree-lua.txt

@@ -1494,6 +1494,23 @@ api.config.mappings.default()        *nvim-tree.api.config.mappings.default()*
     Return: ~
         (table) as per |nvim-tree.view.mappings.list|
 
+                                  *nvim-tree.api.config.mappings.get_keymap()*
+api.config.mappings.get_keymap()
+    Retrieves all buffer local mappings for nvim-tree.
+    These are the mappings that are applied by |nvim-tree.on_attach|, which
+    may include default mappings.
+
+    Return: ~
+        (table) as per |nvim_buf_get_keymap()|
+
+                                  *nvim-tree.api.config.mappings.get_keymap()*
+api.config.mappings.get_keymap_default()
+    Retrieves the buffer local mappings for nvim-tree that are applied by
+    |nvim-tree.api.config.mappings.default_on_attach()|
+
+    Return: ~
+        (table) as per |nvim_buf_get_keymap()|
+
 ==============================================================================
  6. MAPPINGS                                              *nvim-tree-mappings*
 

lua/nvim-tree/api.lua

@@ -182,4 +182,11 @@ Api.config.mappings.default = function()
   return require("nvim-tree.keymap-legacy").default_mappings_clone()
 end
 
+Api.config.mappings.get_keymap = function()
+  return require("nvim-tree.keymap").get_keymap()
+end
+Api.config.mappings.get_keymap_default = function()
+  return require("nvim-tree.keymap").get_keymap_default()
+end
+
 return Api

lua/nvim-tree/keymap.lua

@@ -1,5 +1,24 @@
 local M = {}
 
+--- Apply mappings to a scratch buffer and return buffer local mappings
+--- @param fn function(bufnr) on_attach or default_on_attach
+--- @return table as per vim.api.nvim_buf_get_keymap
+local function generate_keymap(fn)
+  -- create an unlisted scratch buffer
+  local scratch_bufnr = vim.api.nvim_create_buf(false, true)
+
+  -- apply mappings
+  fn(scratch_bufnr)
+
+  -- retrieve all
+  local keymap = vim.api.nvim_buf_get_keymap(scratch_bufnr, "")
+
+  -- delete the scratch buffer
+  vim.api.nvim_buf_delete(scratch_bufnr, { force = true })
+
+  return keymap
+end
+
 -- stylua: ignore start
 function M.default_on_attach(bufnr)
   local api = require('nvim-tree.api')
@@ -65,6 +84,14 @@ function M.default_on_attach(bufnr)
 end
 -- stylua: ignore end
 
+function M.get_keymap()
+  return generate_keymap(M.on_attach)
+end
+
+function M.get_keymap_default()
+  return generate_keymap(M.default_on_attach)
+end
+
 function M.setup(opts)
   if type(opts.on_attach) ~= "function" then
     M.on_attach = M.default_on_attach