neovim/test/functional/ui/decorations_spec.lua

local helpers = require('test.functional.helpers')(after_each)
local Screen = require('test.functional.ui.screen')

local clear = helpers.clear
local feed = helpers.feed
local insert = helpers.insert
local exec_lua = helpers.exec_lua
local expect_events = helpers.expect_events

describe('decorations provider', function()
  local screen
  before_each(function()
    clear()
    screen = Screen.new(40, 8)
    screen:attach()
    screen:set_default_attr_ids({
      [1] = {bold=true, foreground=Screen.colors.Blue},
    })
  end)

  local mudholland = [[
    // just to see if there was an accident
    // on Mulholland Drive
    try_start();
    bufref_T save_buf;
    switch_buffer(&save_buf, buf);
    posp = getmark(mark, false);
    restore_buffer(&save_buf); ]]

  local function setup_provider(code)
    exec_lua ([[
      local a = vim.api
      test1 = a.nvim_create_namespace "test1"
    ]] .. (code or [[
      beamtrace = {}
      function on_do(kind, ...)
        table.insert(beamtrace, {kind, ...})
      end
    ]]) .. [[
      a.nvim_set_decoration_provider(
        test1, {
        on_start = on_do; on_buf = on_do;
        on_win = on_do; on_line = on_do;
        on_end = on_do;
      })
    ]])
  end

  local function check_trace(expected)
    local actual = exec_lua [[ local b = beamtrace beamtrace = {} return b ]]
    expect_events(expected, actual, "beam trace")
  end

  it('leaves a trace', function()
    insert(mudholland)

    setup_provider()

    screen:expect{grid=[[
      // just to see if there was an accident |
      // on Mulholland Drive                  |
      try_start();                            |
      bufref_T save_buf;                      |
      switch_buffer(&save_buf, buf);          |
      posp = getmark(mark, false);            |
      restore_buffer(&save_buf);^              |
                                              |
    ]]}
    check_trace {
      { "start", 4, 40 };
      { "win", 1000, 1, 0, 8 };
      { "line", 1000, 1, 0 };
      { "line", 1000, 1, 1 };
      { "line", 1000, 1, 2 };
      { "line", 1000, 1, 3 };
      { "line", 1000, 1, 4 };
      { "line", 1000, 1, 5 };
      { "line", 1000, 1, 6 };
      { "end", 4 };
    }

    feed "iü<esc>"
    screen:expect{grid=[[
      // just to see if there was an accident |
      // on Mulholland Drive                  |
      try_start();                            |
      bufref_T save_buf;                      |
      switch_buffer(&save_buf, buf);          |
      posp = getmark(mark, false);            |
      restore_buffer(&save_buf);^ü             |
                                              |
    ]]}
    check_trace {
      { "start", 5, 10 };
      { "buf", 1 };
      { "win", 1000, 1, 0, 8 };
      { "line", 1000, 1, 6 };
      { "end", 5 };
    }
  end)

  it('single provider', function()
    insert(mudholland)
    setup_provider [[
      local hl = a.nvim_get_hl_id_by_name "ErrorMsg"
      function do_it(event, ...)
        if event == "line" then
          local win, buf, line = ...
          a.nvim_buf_set_extmark(buf, test_ns, line, line,
                             { end_line = line, end_col = line+1,
                               hl_group = hl,
                               ephemeral = true
                              })
        end
      end
    ]]
  end)
end)