neovim/test/functional/lua/ui_event_spec.lua

local helpers = require('test.functional.helpers')(after_each)
local Screen = require('test.functional.ui.screen')
local eq = helpers.eq
local exec_lua = helpers.exec_lua
local clear = helpers.clear
local feed = helpers.feed
local funcs = helpers.funcs
local inspect = require'vim.inspect'

describe('vim.ui_attach', function()
  local screen
  before_each(function()
    clear()
    exec_lua [[
      ns = vim.api.nvim_create_namespace 'testspace'
      events = {}
      function on_event(event, ...)
        events[#events+1] = {event, ...}
        return true
      end

      function get_events()
        local ret_events = events
        events = {}
        return ret_events
      end
    ]]

    screen = Screen.new(40,5)
    screen:set_default_attr_ids({
      [1] = {bold = true, foreground = Screen.colors.Blue1};
      [2] = {bold = true};
      [3] = {background = Screen.colors.Grey};
      [4] = {background = Screen.colors.LightMagenta};
    })
    screen:attach()
  end)

  local function expect_events(expected)
    local evs = exec_lua "return get_events(...)"
    eq(expected, evs, inspect(evs))
  end

  it('can receive popupmenu events', function()
    exec_lua [[ vim.ui_attach(ns, {ext_popupmenu=true}, on_event) ]]
    feed('ifo')
    screen:expect{grid=[[
      fo^                                      |
      {1:~                                       }|
      {1:~                                       }|
      {1:~                                       }|
      {2:-- INSERT --}                            |
    ]]}

    funcs.complete(1, {'food', 'foobar', 'foo'})
    screen:expect{grid=[[
      food^                                    |
      {1:~                                       }|
      {1:~                                       }|
      {1:~                                       }|
      {2:-- INSERT --}                            |
    ]]}
    expect_events {
      { "popupmenu_show", { { "food", "", "", "" }, { "foobar", "", "", "" }, { "foo", "", "", "" } }, 0, 0, 0, 1 };
    }

    feed '<c-n>'
    screen:expect{grid=[[
      foobar^                                  |
      {1:~                                       }|
      {1:~                                       }|
      {1:~                                       }|
      {2:-- INSERT --}                            |
    ]]}
    expect_events {
       { "popupmenu_select", 1 };
    }

    feed '<c-y>'
    -- There is an intermediate state where the 'showmode' message disappears.
    screen:expect_unchanged(true)
    expect_events {
       { "popupmenu_hide" };
    }

    -- vim.ui_detach() stops events, and reenables builtin pum immediately
    exec_lua [[
      vim.ui_detach(ns)
      vim.fn.complete(1, {'food', 'foobar', 'foo'})
    ]]

    screen:expect{grid=[[
      food^                                    |
      {3:food           }{1:                         }|
      {4:foobar         }{1:                         }|
      {4:foo            }{1:                         }|
      {2:-- INSERT --}                            |
    ]]}
    expect_events {
    }

  end)

  it('does not crash on exit', function()
    helpers.funcs.system({
      helpers.nvim_prog,
      '-u', 'NONE',
      '-i', 'NONE',
      '--cmd', [[ lua ns = vim.api.nvim_create_namespace 'testspace' ]],
      '--cmd', [[ lua vim.ui_attach(ns, {ext_popupmenu=true}, function() end) ]],
      '--cmd', 'quitall!',
    })
    eq(0, helpers.eval('v:shell_error'))
  end)

  it('can receive accurate message kinds even if they are history', function()
    exec_lua([[
    vim.cmd.echomsg("'message1'")
    print('message2')
    vim.ui_attach(ns, { ext_messages = true }, on_event)
    vim.cmd.echomsg("'message3'")
    ]])
    feed(':messages<cr>')
    feed('<cr>')

    local actual = exec_lua([[
    return vim.tbl_filter(function (event)
      return event[1] == "msg_history_show"
    end, events)
    ]])
    eq({
      {
        'msg_history_show',
        {
          { 'echomsg', { { 0, 'message1' } } },
          { '', { { 0, 'message2' } } },
          { 'echomsg', { { 0, 'message3' } } },
        },
      },
    }, actual, inspect(actual))
  end)
end)