fix: reload open buffer via checktime when server edits a file

lua/eca/sidebar.lua

@@ -1302,7 +1302,18 @@ function M:handle_chat_content_received(params)
     if details and type(details) == "table" and details.type == "fileChange" then
       local path = details.path
       if path and path ~= "" then
-        local filename = vim.fn.fnamemodify(path, ":t")
+        local absolute_path = vim.fn.fnamemodify(path, ":p")
+
+        -- If this file is already loaded in a buffer, refresh it so users see
+        -- server-side edits immediately without needing :e or :checktime.
+        local bufnr = vim.fn.bufnr(absolute_path)
+        if bufnr ~= -1 and vim.api.nvim_buf_is_loaded(bufnr) then
+          vim.api.nvim_buf_call(bufnr, function()
+            vim.cmd("checktime")
+          end)
+        end
+
+        local filename = vim.fn.fnamemodify(absolute_path, ":t")
         if filename and filename ~= "" then
           -- Avoid duplicating the filename if it is already present
           if tool_text and tool_text ~= "" then

tests/test_sidebar_buffer_reload.lua

@@ -0,0 +1,192 @@
+local MiniTest = require("mini.test")
+local eq = MiniTest.expect.equality
+local child = MiniTest.new_child_neovim()
+
+local function flush(ms)
+  vim.uv.sleep(ms or 80)
+  child.api.nvim_eval("1")
+end
+
+local function setup_env()
+  _G.Server = require("eca.server").new()
+  _G.State = require("eca.state").new()
+  _G.Mediator = require("eca.mediator").new(_G.Server, _G.State)
+  _G.Sidebar = require("eca.sidebar").new(1, _G.Mediator)
+
+  _G.Sidebar:open()
+end
+
+local T = MiniTest.new_set({
+  hooks = {
+    pre_case = function()
+      child.restart({ "-u", "scripts/minimal_init.lua" })
+      child.lua_func(setup_env)
+    end,
+    post_case = function()
+      child.lua([[
+        if _G.Sidebar then _G.Sidebar:close() end
+        if _G.test_tmpfile then
+          os.remove(_G.test_tmpfile)
+          _G.test_tmpfile = nil
+        end
+      ]])
+    end,
+    post_once = child.stop,
+  },
+})
+
+local function report_file_change(path)
+  child.lua(string.format(
+    [[
+      Sidebar:handle_chat_content_received({
+        chatId = 'chat-reload',
+        content = {
+          type = 'toolCalled',
+          id = 'tool-reload',
+          name = 'write_file',
+          summary = 'Apply edit',
+          details = { type = 'fileChange', path = %q, diff = '+updated' },
+        },
+      })
+    ]],
+    path
+  ))
+end
+
+T["buffer reload on server file change"] = MiniTest.new_set()
+
+T["buffer reload on server file change"]["reloads a loaded buffer when the server edits its file"] = function()
+  child.lua([[
+    local tmpfile = vim.fn.tempname() .. '.txt'
+    vim.fn.writefile({ 'original content' }, tmpfile)
+    _G.test_tmpfile = tmpfile
+
+    vim.cmd('edit ' .. vim.fn.fnameescape(tmpfile))
+    _G.test_bufnr = vim.api.nvim_get_current_buf()
+
+    -- Simulate the server writing new content behind Neovim's back, and
+    -- force the mtime forward so :checktime reliably detects the change
+    -- even on filesystems with coarse mtime resolution.
+    vim.fn.writefile({ 'updated content from server' }, tmpfile)
+    local future = os.time() + 5
+    vim.uv.fs_utime(tmpfile, future, future)
+  ]])
+
+  local tmpfile = child.lua_get("_G.test_tmpfile")
+  report_file_change(tmpfile)
+  flush(150)
+
+  local lines = child.lua_get("vim.api.nvim_buf_get_lines(_G.test_bufnr, 0, -1, false)")
+  eq(lines, { "updated content from server" })
+end
+
+T["buffer reload on server file change"]["does not error when the changed file has no loaded buffer"] = function()
+  child.lua([[
+    local tmpfile = vim.fn.tempname() .. '.txt'
+    vim.fn.writefile({ 'not open in any buffer' }, tmpfile)
+    _G.test_tmpfile = tmpfile
+  ]])
+
+  local tmpfile = child.lua_get("_G.test_tmpfile")
+
+  local ok = child.lua_get(string.format(
+    [[(pcall(function()
+      Sidebar:handle_chat_content_received({
+        chatId = 'chat-reload',
+        content = {
+          type = 'toolCalled',
+          id = 'tool-reload',
+          name = 'write_file',
+          summary = 'Apply edit',
+          details = { type = 'fileChange', path = %q, diff = '+updated' },
+        },
+      })
+    end))]],
+    tmpfile
+  ))
+
+  eq(ok, true)
+end
+
+T["buffer reload on server file change"]["does not discard unsaved local edits in the buffer"] = function()
+  child.lua([[
+    local tmpfile = vim.fn.tempname() .. '.txt'
+    vim.fn.writefile({ 'original content' }, tmpfile)
+    _G.test_tmpfile = tmpfile
+
+    vim.cmd('edit ' .. vim.fn.fnameescape(tmpfile))
+    _G.test_bufnr = vim.api.nvim_get_current_buf()
+
+    -- Make an unsaved local edit before the server writes to the file.
+    vim.api.nvim_buf_set_lines(_G.test_bufnr, 0, -1, false, { 'local unsaved edit' })
+
+    vim.fn.writefile({ 'updated content from server' }, tmpfile)
+    local future = os.time() + 5
+    vim.uv.fs_utime(tmpfile, future, future)
+  ]])
+
+  local tmpfile = child.lua_get("_G.test_tmpfile")
+  report_file_change(tmpfile)
+  flush(150)
+
+  local lines = child.lua_get("vim.api.nvim_buf_get_lines(_G.test_bufnr, 0, -1, false)")
+  eq(lines, { "local unsaved edit" })
+end
+
+T["buffer reload on server file change"]["resolves a relative path to the loaded buffer's absolute path"] = function()
+  child.lua([[
+    local tmpfile = vim.fn.tempname() .. '.txt'
+    vim.fn.writefile({ 'original content' }, tmpfile)
+    _G.test_tmpfile = tmpfile
+
+    vim.cmd('edit ' .. vim.fn.fnameescape(tmpfile))
+    _G.test_bufnr = vim.api.nvim_get_current_buf()
+
+    vim.fn.writefile({ 'updated content from server' }, tmpfile)
+    local future = os.time() + 5
+    vim.uv.fs_utime(tmpfile, future, future)
+
+    -- The server may report a path relative to the current directory
+    -- rather than an absolute one.
+    _G.test_relative_path = vim.fn.fnamemodify(tmpfile, ':.')
+  ]])
+
+  local relative_path = child.lua_get("_G.test_relative_path")
+  report_file_change(relative_path)
+  flush(150)
+
+  local lines = child.lua_get("vim.api.nvim_buf_get_lines(_G.test_bufnr, 0, -1, false)")
+  eq(lines, { "updated content from server" })
+end
+
+T["buffer reload on server file change"]["still appends the filename to the tool call summary"] = function()
+  child.lua([[
+    local tmpfile = vim.fn.tempname() .. '.txt'
+    vim.fn.writefile({ 'original content' }, tmpfile)
+    _G.test_tmpfile = tmpfile
+
+    vim.cmd('edit ' .. vim.fn.fnameescape(tmpfile))
+    _G.test_bufnr = vim.api.nvim_get_current_buf()
+
+    vim.fn.writefile({ 'updated content from server' }, tmpfile)
+    local future = os.time() + 5
+    vim.uv.fs_utime(tmpfile, future, future)
+  ]])
+
+  local tmpfile = child.lua_get("_G.test_tmpfile")
+  report_file_change(tmpfile)
+  flush(150)
+
+  child.lua([[
+    local call = Sidebar._tool_calls[1]
+    local buf = Sidebar.containers.chat.bufnr
+    _G.file_summary_header = call and vim.api.nvim_buf_get_lines(buf, call.header_line - 1, call.header_line, false)[1] or ''
+  ]])
+
+  local header = child.lua_get("_G.file_summary_header")
+  local expected_name = child.lua_get(string.format("vim.fn.fnamemodify(%q, ':t')", tmpfile))
+  local has_filename = child.lua_get(string.format("string.find(..., %q, 1, true) ~= nil", expected_name), { header })
+  eq(has_filename, true)
+end
+
+return T