fix(fallback): make fallback work with buffer-local mappings

lua/blink/cmp/keymap/apply.lua

@@ -14,11 +14,13 @@ function apply.keymap_to_current_buffer(keys_to_commands)
   for key, commands in pairs(keys_to_commands) do
     if #commands == 0 then goto continue end
 
+    local fallback = require('blink.cmp.keymap.fallback').wrap('i', key)
+
     apply.set('i', key, function()
       for _, command in ipairs(commands) do
         -- special case for fallback
         if command == 'fallback' then
-          return require('blink.cmp.keymap.fallback').run_non_blink_keymap('i', key)
+          return fallback()
 
         -- run user defined functions
         elseif type(command) == 'function' then
@@ -42,11 +44,13 @@ function apply.keymap_to_current_buffer(keys_to_commands)
     end
     if not has_snippet_command or #commands == 0 then goto continue end
 
+    local fallback = require('blink.cmp.keymap.fallback').wrap('s', key)
+
     apply.set('s', key, function()
       for _, command in ipairs(keys_to_commands[key] or {}) do
         -- special case for fallback
         if command == 'fallback' then
-          return require('blink.cmp.keymap.fallback').run_non_blink_keymap('s', key)
+          return fallback()
 
           -- run user defined functions
         elseif type(command) == 'function' then

lua/blink/cmp/keymap/fallback.lua

@@ -1,29 +1,57 @@
 local fallback = {}
 
---- Gets the first non blink.cmp keymap for the given mode and key
+--- Add missing types. Remove when fixed upstream
+---@class vim.api.keyset.keymap
+---@field lhs string
+---@field mode string
+---@field rhs? string
+---@field lhsraw? string
+---@field buffer? number
+
+--- Gets the non blink.cmp global keymap for the given mode and key
 --- @param mode string
 --- @param key string
 --- @return vim.api.keyset.keymap | nil
-function fallback.get_non_blink_mapping_for_key(mode, key)
+function fallback.get_non_blink_global_mapping_for_key(mode, key)
   local normalized_key = vim.api.nvim_replace_termcodes(key, true, true, true)
 
-  -- get buffer local and global mappings
-  local mappings = vim.api.nvim_buf_get_keymap(0, mode)
-  vim.list_extend(mappings, vim.api.nvim_get_keymap(mode))
+  -- get global mappings
+  local mappings = vim.api.nvim_get_keymap(mode)
 
   for _, mapping in ipairs(mappings) do
     local mapping_key = vim.api.nvim_replace_termcodes(mapping.lhs, true, true, true)
     if mapping_key == normalized_key and mapping.desc ~= 'blink.cmp' then return mapping end
   end
 end
 
---- Runs the first non blink.cmp keymap for the given mode and key
+--- Gets the non blink.cmp buffer keymap for the given mode and key
 --- @param mode string
 --- @param key string
---- @return string | nil
-function fallback.run_non_blink_keymap(mode, key)
-  local mapping = fallback.get_non_blink_mapping_for_key(mode, key) or {}
+--- @return vim.api.keyset.keymap?
+function fallback.get_non_blink_buffer_mapping_for_key(mode, key)
+  local ret = vim.fn.maparg(key, mode, false, true) --[[@as vim.api.keyset.keymap]]
+  if ret and ret.buffer == 0 then return end
+  if ret and ret.desc and ret.desc == 'blink.cmp' then return end
+  return ret.lhs ~= nil and ret or nil
+end
 
+--- Returns a function that will run the first non blink.cmp keymap for the given mode and key
+--- @param mode string
+--- @param key string
+--- @return fun(): string?
+function fallback.wrap(mode, key)
+  local buffer_mapping = fallback.get_non_blink_buffer_mapping_for_key(mode, key)
+  return function()
+    local mapping = buffer_mapping or fallback.get_non_blink_global_mapping_for_key(mode, key)
+    if mapping then return fallback.run_non_blink_keymap(mapping, key) end
+  end
+end
+
+--- Runs the first non blink.cmp keymap for the given mode and key
+--- @param mapping vim.api.keyset.keymap
+--- @param key string
+--- @return string | nil
+function fallback.run_non_blink_keymap(mapping, key)
   -- TODO: there's likely many edge cases here. the nvim-cmp version is lacking documentation
   -- and is quite complex. we should look to see if we can simplify their logic
   -- https://github.com/hrsh7th/nvim-cmp/blob/ae644feb7b67bf1ce4260c231d1d4300b19c6f30/lua/cmp/utils/keymap.lua
@@ -36,7 +64,9 @@ function fallback.run_non_blink_keymap(mode, key)
     end
 
     local expr = mapping.callback()
-    if mapping.replace_keycodes == 1 then expr = vim.api.nvim_replace_termcodes(expr, true, true, true) end
+    if type(expr) == 'string' and mapping.replace_keycodes == 1 then
+      expr = vim.api.nvim_replace_termcodes(expr, true, true, true)
+    end
     return expr
   elseif mapping.rhs then
     local rhs = vim.api.nvim_replace_termcodes(mapping.rhs, true, true, true)