Add firenvim#write() function enabling users to write arbitrary data

The goal of this commit is to enable the use case desired by #1589. This
isn't a perfect fit as the user was asking for a way to setup
post-processing of their text instead of having to call firenvim#write,
but as I am on a tight schedule for publishing a new release I do not
have time for further discussions, and following the pattern of
firenvim#hide_frame, firenvim#eval_js, firenvim#focus_* feels like a
very safe choice.

autoload/firenvim.vim

@@ -50,6 +50,25 @@ function! firenvim#hide_frame() abort
  call rpcnotify(firenvim#get_chan(), 'firenvim_hide_frame')
 endfunction
 
+" Asks the browser extension to write to the text area. Either two or no
+" arguments.
+" 1st arg: string to write
+" 2nd arg: position of the cursor
+function! firenvim#write(...) abort
+ let l:text = ''
+ let l:cursor = [0, 0]
+ if len(a:000) == 0
+ let l:text = nvim_buf_get_lines(0, 0, -1, 0)
+ let l:cursor = nvim_win_get_cursor(0)
+ elseif len(a:000) == 2
+ let l:text = a:0
+ let l:cursor = a:1
+ else
+ throw 'firenvim#write should be called either with 0 arguments or with 2 arguments (string, [number, number])'
+ endif
+ call rpcnotify(firenvim#get_chan(), 'firenvim_bufwrite', {'text': l:text, 'cursor': l:cursor})
+endfunction
+
 " Asks the browser extension to send one or multiple key events to the
 " underlying input field.
 function! firenvim#press_keys(...) abort

src/frame.ts

@@ -118,14 +118,7 @@ export const isReady = browser
  group = group,
  pattern = filename,
  callback = function(ev)
- vim.fn.rpcnotify(
- channel,
- "firenvim_bufwrite",
- {
- text = vim.api.nvim_buf_get_lines(0, 0, -1, 0),
- cursor = vim.api.nvim_win_get_cursor(0)
- }
- )
+ vim.fn["firenvim#write"]()
  end
  })
  vim.api.nvim_create_autocmd("VimLeave", {