Manually implement auto mass-renaming using LSP

home/.config/nvim/lua/lsp/rename.lua

@@ -1,3 +1,160 @@
 -- Nvim's LSP lacks rename-all functionality which plugins like Coc provide
 -- this is a manual implementation of this feature
--- TODO: Actually implement this
+local vim = require("vim")
+local api = vim.api
+local cmd = vim.cmd
+local lsp = vim.lsp
+local fn = vim.fn
+
+local M = {}
+
+-- Unique name for the rename window, so we can access it
+-- from close_rename_win function.
+local unique_name = "lsp-rename-win"
+
+-- File require string. Neede because we will be defining keymaps
+-- applied only to the rename window buffer which will refer to
+-- functions within this file, for that, they need to call require
+local file_require_string = "lsp.rename"
+
+-- Check whether LSP is actually active.
+local function check_lsp_active()
+    local active_clients = lsp.get_active_clients()
+    if next(active_clients) == nil then
+        return false
+    end
+    return true
+end
+
+-- Once in the rename window buffer, apply specific mappings to confirm or
+-- cancel renaming, and define a specific autocmd to close the window if
+-- we leave it.
+local function apply_actions()
+    local prefix = string.format("lua require('%s')", file_require_string)
+    local close_win_s = prefix .. ".close_rename_win()"
+    local do_rename_s = prefix .. ".do_rename()"
+    -- Automatically close the window if it's escaped
+    api.nvim_command("autocmd QuitPre <buffer> ++nested ++once :silent " .. close_win_s)
+    -- Define confirm and exit buffer-specific keymaps
+    api.nvim_command("inoremap <buffer><nowait><silent><CR> <cmd>" .. do_rename_s .. "<CR>")
+    api.nvim_command("nnoremap <buffer><silent>q <cmd>" .. close_win_s .. "<CR>")
+end
+
+-- Closes the rename window (identified by the `unique_name`)
+function M.close_rename_win()
+    if fn.mode() == "1" then
+        cmd[[stopinsert]]
+    end
+
+    local exists, winid = pcall(api.nvim_win_get_var, 0, unique_name)
+    if exists then
+        api.nvim_win_close(winid, true)
+    end
+end
+
+local function dump(o)
+   if type(o) == 'table' then
+      local s = '{ '
+      for k,v in pairs(o) do
+         if type(k) ~= 'number' then k = '"'..k..'"' end
+         s = s .. '['..k..'] = ' .. dump(v) .. ','
+      end
+      return s .. '} '
+   else
+      return tostring(o)
+   end
+end
+
+
+-- Trigger renaming
+function M.do_rename()
+    local new_name = vim.trim(fn.getline('.'))
+    M.close_rename_win()
+    local current_name = fn.expand("<cword>")
+
+    if not new_name or #new_name == 0 or new_name == current_name then
+        return
+    end
+
+    local params = lsp.util.make_position_params()
+    params.newName = new_name
+    lsp.buf_request(0, "textDocument/rename", params, function(_, result, _, _)
+        if not result then
+            -- If the server returns an empty result, don't do anything
+            return
+        end
+
+        -- The result contains all places we need to update the name
+        -- of the identifier, so we apply those edits.
+        lsp.util.apply_workspace_edit(result)
+
+        if not result.changes then
+            return
+        end
+
+        local total_files = 0
+        local total_renames = 0
+        for _, renames in pairs(result.changes) do
+            total_files = total_files + 1
+            for _ in pairs(renames) do
+                total_renames = total_renames + 1
+            end
+        end
+
+        -- Once the changes were applied, these files won't be saved
+        -- automatically, let's remind ourselves to save those...
+        print(string.format(
+            "Changed %s file%s (%s rename%s). To save %s, run ':w%s'",
+            total_files,
+            total_files > 1 and "s" or "",
+            total_renames,
+            total_renames > 1 and "s" or "",
+            total_files > 1 and "them" or "it",
+            total_files > 1 and "a" or ""
+        ))
+    end)
+end
+
+-- Create the rename window
+function M.rename()
+    if not check_lsp_active() then
+        print("No LSP client available, can't rename!")
+        return
+    end
+
+    -- In case there already is another rename window opened, close it
+    M.close_rename_win()
+
+
+    -- Read the current name here, before we're in the rename window
+    local current_name = fn.expand('<cword>')
+
+    -- Create a window within our buffer with our `unique_name` so that it
+    -- can be found from the close fucntion and automatically enter it
+    local win_opts = {
+        relative = 'cursor',
+        row = 0,
+        col = 0,
+        width = 30,
+        height = 1,
+        style = 'minimal',
+        border = 'single'
+    }
+    local buf = api.nvim_create_buf(false, true)
+    local win = api.nvim_open_win(buf, true, win_opts)
+    api.nvim_win_set_var(0, unique_name, win)
+
+    -- Automatically enter insert mode
+    cmd[[startinsert]]
+
+    -- Pre-write the current name of given object into the rename window
+    -- and set cursor behind it
+    api.nvim_buf_set_lines(buf, 0, -1, false, {current_name})
+    api.nvim_win_set_cursor(win, {1, #current_name})
+
+    -- Set actions for auto-closing the window and buffer-specific mappings
+    -- to confirm or close rename
+    apply_actions()
+end
+
+return M