neovim/test/functional/legacy/conceal_spec.lua

local t = require('test.testutil')
local n = require('test.functional.testnvim')()
local Screen = require('test.functional.ui.screen')

local clear = n.clear
local command = n.command
local exec = n.exec
local feed = n.feed
local api = n.api

local expect_pos = function(row, col)
  return t.eq({ row, col }, n.eval('[screenrow(), screencol()]'))
end

describe('Conceal', function()
  before_each(function()
    clear()
    command('set nohlsearch')
  end)

  -- oldtest: Test_conceal_two_windows()
  it('works', function()
    local screen = Screen.new(75, 12)
    screen:attach()
    exec([[
      let lines = ["one one one one one", "two |hidden| here", "three |hidden| three"]
      call setline(1, lines)
      syntax match test /|hidden|/ conceal
      set conceallevel=2
      set concealcursor=
      exe "normal /here\r"
      new
      call setline(1, lines)
      call setline(4, "Second window")
      syntax match test /|hidden|/ conceal
      set conceallevel=2
      set concealcursor=nc
      exe "normal /here\r"
    ]])

    -- Check that cursor line is concealed
    screen:expect([[
      one one one one one                                                        |
      two  ^here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])

    -- Check that with concealed text vertical cursor movement is correct.
    feed('k')
    screen:expect([[
      one one one o^ne one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])

    -- Check that with cursor line is not concealed
    feed('j')
    command('set concealcursor=')
    screen:expect([[
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])

    -- Check that with cursor line is not concealed when moving cursor down
    feed('j')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three |hidden^| three                                                       |
      Second window                                                              |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])

    -- Check that with cursor line is not concealed when switching windows
    feed('<C-W><C-W>')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])

    -- Check that with cursor line is only concealed in Normal mode
    command('set concealcursor=n')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  ^here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      /here                                                                      |
    ]])
    feed('a')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h^ere                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Esc>/e')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h{2:e}re                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      /e^                                                                         |
    ]])
    feed('<Esc>v')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- VISUAL --}                                                               |
    ]])
    feed('<Esc>')

    -- Check that with cursor line is only concealed in Insert mode
    command('set concealcursor=i')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
                                                                                 |
    ]])
    feed('a')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  h^ere                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Esc>/e')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h{2:e}re                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      /e^                                                                         |
    ]])
    feed('<Esc>v')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- VISUAL --}                                                               |
    ]])
    feed('<Esc>')

    -- Check that with cursor line is only concealed in Visual mode
    command('set concealcursor=v')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| ^here                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
                                                                                 |
    ]])
    feed('a')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h^ere                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Esc>/e')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h{2:e}re                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      /e^                                                                         |
    ]])
    feed('<Esc>v')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  ^here                                                                  |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- VISUAL --}                                                               |
    ]])
    feed('<Esc>')

    -- Check moving the cursor while in insert mode.
    command('set concealcursor=')
    feed('a')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two |hidden| h^ere                                                          |
      three  three                                                               |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Down>')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three |hidden|^ three                                                       |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Esc>')

    -- Check the "o" command
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three |hidden^| three                                                       |
      {1:~                                                                          }|
      {3:[No Name] [+]                                                              }|
                                                                                 |
    ]])
    feed('o')
    screen:expect([[
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      Second window                                                              |
      {1:~                                                                          }|
      {2:[No Name] [+]                                                              }|
      one one one one one                                                        |
      two  here                                                                  |
      three  three                                                               |
      ^                                                                           |
      {3:[No Name] [+]                                                              }|
      {5:-- INSERT --}                                                               |
    ]])
    feed('<Esc>')
  end)

  -- oldtest: Test_conceal_with_cursorcolumn()
  it('CursorColumn and ColorColumn on wrapped line', function()
    local screen = Screen.new(40, 10)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue }, -- NonText
      [1] = { background = Screen.colors.Grey90 }, -- CursorColumn
      [2] = { background = Screen.colors.LightRed }, -- ColorColumn
    })
    screen:attach()
    -- Check that cursorcolumn and colorcolumn don't get broken in presence of
    -- wrapped lines containing concealed text
    -- luacheck: push ignore 613 (trailing whitespace in a string)
    exec([[
      let lines = ["one one one |hidden| one one one one one one one one",
            \ "two two two two |hidden| here two two",
            \ "three |hidden| three three three three three three three three"]
      call setline(1, lines)
      set wrap linebreak
      set showbreak=\ >>>\ 
      syntax match test /|hidden|/ conceal
      set conceallevel=2
      set concealcursor=
      exe "normal /here\r"
      set cursorcolumn
      set colorcolumn=50
    ]])
    -- luacheck: pop

    screen:expect([[
      one one one  one one one {1:o}ne            |
      {0: >>> }one {2:o}ne one one                    |
      two two two two |hidden| ^here two two   |
      three  three three three {1:t}hree          |
      {0: >>> }thre{2:e} three three three            |
      {0:~                                       }|*4
      /here                                   |
    ]])

    -- move cursor to the end of line (the cursor jumps to the next screen line)
    feed('$')
    screen:expect([[
      one one one  one one one one            |
      {0: >>> }one {2:o}ne one one                    |
      two two two two |hidden| here two tw^o   |
      three  three three three three          |
      {0: >>> }thre{2:e} three three three            |
      {0:~                                       }|*4
      /here                                   |
    ]])
  end)

  -- oldtest: Test_conceal_wrapped_cursorline_wincolor()
  it('CursorLine highlight on wrapped lines', function()
    local screen = Screen.new(40, 4)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue }, -- NonText
      [1] = { background = Screen.colors.Green }, -- CursorLine (low-priority)
      [2] = { foreground = Screen.colors.Red }, -- CursorLine (high-priority)
    })
    screen:attach()
    exec([[
      call setline(1, 'one one one |hidden| one one one one one one one one')
      syntax match test /|hidden|/ conceal
      set conceallevel=2 concealcursor=n cursorline
      normal! g$
      hi! CursorLine guibg=Green
    ]])
    screen:expect([[
      {1:one one one  one one one one on^e        }|
      {1: one one one                            }|
      {0:~                                       }|
                                              |
    ]])
    command('hi! CursorLine guibg=NONE guifg=Red')
    screen:expect([[
      {2:one one one  one one one one on^e        }|
      {2: one one one                            }|
      {0:~                                       }|
                                              |
    ]])
  end)

  -- oldtest: Test_conceal_wrapped_cursorline_wincolor_rightleft()
  it('CursorLine highlight on wrapped lines with rightleft', function()
    local screen = Screen.new(40, 4)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue }, -- NonText
      [1] = { background = Screen.colors.Green }, -- CursorLine (low-priority)
      [2] = { foreground = Screen.colors.Red }, -- CursorLine (high-priority)
    })
    screen:attach()
    exec([[
      call setline(1, 'one one one |hidden| one one one one one one one one')
      syntax match test /|hidden|/ conceal
      set conceallevel=2 concealcursor=n cursorline rightleft
      normal! g$
      hi! CursorLine guibg=Green
    ]])
    screen:expect([[
      {1:        ^eno eno eno eno eno  eno eno eno}|
      {1:                            eno eno eno }|
      {0:                                       ~}|
                                              |
    ]])
    command('hi! CursorLine guibg=NONE guifg=Red')
    screen:expect([[
      {2:        ^eno eno eno eno eno  eno eno eno}|
      {2:                            eno eno eno }|
      {0:                                       ~}|
                                              |
    ]])
  end)

  -- oldtest: Test_conceal_resize_term()
  it('resize editor', function()
    local screen = Screen.new(75, 6)
    screen:attach()
    exec([[
      call setline(1, '`one` `two` `three` `four` `five`, the backticks should be concealed')
      setl cocu=n cole=3
      syn region CommentCodeSpan matchgroup=Comment start=/`/ end=/`/ concealends
      normal fb
    ]])
    screen:expect([[
      one two three four five, the ^backticks should be concealed                 |
      {1:~                                                                          }|*4
                                                                                 |
    ]])

    screen:try_resize(75, 7)
    screen:expect([[
      one two three four five, the ^backticks should be concealed                 |
      {1:~                                                                          }|*5
                                                                                 |
    ]])
  end)

  -- oldtest: Test_conceal_linebreak()
  it('with linebreak', function()
    local screen = Screen.new(75, 8)
    screen:attach()
    exec([[
      let &wrap = v:true
      let &conceallevel = 2
      let &concealcursor = 'nc'
      let &linebreak = v:true
      let &showbreak = '+ '
      let line = 'a`a`a`a`'
          \ .. 'a'->repeat(&columns - 15)
          \ .. ' b`b`'
          \ .. 'b'->repeat(&columns - 10)
          \ .. ' cccccc'
      eval ['x'->repeat(&columns), '', line]->setline(1)
      syntax region CodeSpan matchgroup=Delimiter start=/\z(`\+\)/ end=/\z1/ concealends
    ]])
    screen:expect([[
      ^xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
                                                                                 |
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa           |
      {1:+ }bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb      |
      {1:+ }cccccc                                                                   |
      {1:~                                                                          }|*2
                                                                                 |
    ]])
  end)

  -- Tests for correct display (cursor column position) with +conceal and tabulators.
  -- oldtest: Test_conceal_cursor_pos()
  it('cursor and column position with conceal and tabulators', function()
    exec([[
      let l = ['start:', '.concealed.     text', "|concealed|\ttext"]
      let l += ['', "\t.concealed.\ttext", "\t|concealed|\ttext", '']
      let l += [".a.\t.b.\t.c.\t.d.", "|a|\t|b|\t|c|\t|d|"]
      call append(0, l)
      call cursor(1, 1)
      " Conceal settings.
      set conceallevel=2
      set concealcursor=nc
      syntax match test /|/ conceal
    ]])
    feed('ztj')
    expect_pos(2, 1)
    -- We should end up in the same column when running these commands on the
    -- two lines.
    feed('ft')
    expect_pos(2, 17)
    feed('$')
    expect_pos(2, 20)
    feed('0j')
    expect_pos(3, 1)
    feed('ft')
    expect_pos(3, 17)
    feed('$')
    expect_pos(3, 20)
    feed('j0j')
    expect_pos(5, 8)
    -- Same for next test block.
    feed('ft')
    expect_pos(5, 25)
    feed('$')
    expect_pos(5, 28)
    feed('0j')
    expect_pos(6, 8)
    feed('ft')
    expect_pos(6, 25)
    feed('$')
    expect_pos(6, 28)
    feed('0j0j')
    expect_pos(8, 1)
    -- And check W with multiple tabs and conceals in a line.
    feed('W')
    expect_pos(8, 9)
    feed('W')
    expect_pos(8, 17)
    feed('W')
    expect_pos(8, 25)
    feed('$')
    expect_pos(8, 27)
    feed('0j')
    expect_pos(9, 1)
    feed('W')
    expect_pos(9, 9)
    feed('W')
    expect_pos(9, 17)
    feed('W')
    expect_pos(9, 25)
    feed('$')
    expect_pos(9, 26)
    command('set lbr')
    feed('$')
    expect_pos(9, 26)
    command('set list listchars=tab:>-')
    feed('0')
    expect_pos(9, 1)
    feed('W')
    expect_pos(9, 9)
    feed('W')
    expect_pos(9, 17)
    feed('W')
    expect_pos(9, 25)
    feed('$')
    expect_pos(9, 26)
  end)

  local function test_conceal_virtualedit_after_eol(wrap)
    local screen = Screen.new(60, 3)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue }, -- NonText
    })
    screen:attach()
    api.nvim_set_option_value('wrap', wrap, {})
    exec([[
      call setline(1, 'abcdefgh|hidden|ijklmnpop')
      syntax match test /|hidden|/ conceal
      set conceallevel=2 concealcursor=n virtualedit=all
      normal! $
    ]])
    screen:expect([[
      abcdefghijklmnpo^p                                           |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('l')
    screen:expect([[
      abcdefghijklmnpop^                                           |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('l')
    screen:expect([[
      abcdefghijklmnpop ^                                          |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('l')
    screen:expect([[
      abcdefghijklmnpop  ^                                         |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('rr')
    screen:expect([[
      abcdefghijklmnpop  ^r                                        |
      {0:~                                                           }|
                                                                  |
    ]])
  end

  -- oldtest: Test_conceal_virtualedit_after_eol()
  describe('cursor drawn at correct column with virtualedit', function()
    it('with wrapping', function()
      test_conceal_virtualedit_after_eol(true)
    end)
    it('without wrapping', function()
      test_conceal_virtualedit_after_eol(false)
    end)
  end)

  local function test_conceal_virtualedit_after_eol_rightleft(wrap)
    local screen = Screen.new(60, 3)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue }, -- NonText
    })
    screen:attach()
    api.nvim_set_option_value('wrap', wrap, {})
    exec([[
      call setline(1, 'abcdefgh|hidden|ijklmnpop')
      syntax match test /|hidden|/ conceal
      set conceallevel=2 concealcursor=n virtualedit=all rightleft
      normal! $
    ]])
    screen:expect([[
                                                 ^popnmlkjihgfedcba|
      {0:                                                           ~}|
                                                                  |
    ]])
    feed('h')
    screen:expect([[
                                                ^ popnmlkjihgfedcba|
      {0:                                                           ~}|
                                                                  |
    ]])
    feed('h')
    screen:expect([[
                                               ^  popnmlkjihgfedcba|
      {0:                                                           ~}|
                                                                  |
    ]])
    feed('h')
    screen:expect([[
                                              ^   popnmlkjihgfedcba|
      {0:                                                           ~}|
                                                                  |
    ]])
    feed('rr')
    screen:expect([[
                                              ^r  popnmlkjihgfedcba|
      {0:                                                           ~}|
                                                                  |
    ]])
  end

  -- oldtest: Test_conceal_virtualedit_after_eol_rightleft()
  describe('cursor drawn correctly with virtualedit and rightleft', function()
    it('with wrapping', function()
      test_conceal_virtualedit_after_eol_rightleft(true)
    end)
    it('without wrapping', function()
      test_conceal_virtualedit_after_eol_rightleft(false)
    end)
  end)

  local function test_conceal_double_width(wrap)
    local screen = Screen.new(60, 4)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue },
      [1] = { background = Screen.colors.DarkGrey, foreground = Screen.colors.LightGrey },
      [2] = { background = Screen.colors.LightRed },
    })
    screen:attach()
    api.nvim_set_option_value('wrap', wrap, {})
    exec([[
      call setline(1, ['aaaaa口=口bbbbb口=口ccccc', 'foobar'])
      syntax match test /口=口/ conceal cchar=β
      set conceallevel=2 concealcursor=n colorcolumn=30
      normal! $
    ]])
    screen:expect([[
      aaaaa{1:β}bbbbb{1:β}cccc^c            {2: }                              |
      foobar                       {2: }                              |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('gM')
    screen:expect([[
      aaaaa{1:β}bb^bbb{1:β}ccccc            {2: }                              |
      foobar                       {2: }                              |
      {0:~                                                           }|
                                                                  |
    ]])
    command('set conceallevel=3')
    screen:expect([[
      aaaaabb^bbbccccc              {2: }                              |
      foobar                       {2: }                              |
      {0:~                                                           }|
                                                                  |
    ]])
    feed('$')
    screen:expect([[
      aaaaabbbbbcccc^c              {2: }                              |
      foobar                       {2: }                              |
      {0:~                                                           }|
                                                                  |
    ]])
  end

  -- oldtest: Test_conceal_double_width()
  describe('cursor drawn correctly when double-width chars are concealed', function()
    it('with wrapping', function()
      test_conceal_double_width(true)
    end)
    it('without wrapping', function()
      test_conceal_double_width(false)
    end)
  end)

  -- oldtest: Test_conceal_double_width_wrap()
  it('line wraps correctly when double-width chars are concealed', function()
    local screen = Screen.new(20, 4)
    screen:set_default_attr_ids({
      [0] = { bold = true, foreground = Screen.colors.Blue },
      [1] = { background = Screen.colors.DarkGrey, foreground = Screen.colors.LightGrey },
      [2] = { background = Screen.colors.LightRed },
    })
    screen:attach()
    exec([[
      call setline(1, 'aaaaaaaaaa口=口bbbbbbbbbb口=口cccccccccc')
      syntax match test /口=口/ conceal cchar=β
      set conceallevel=2 concealcursor=n
      normal! $
    ]])
    screen:expect([[
      aaaaaaaaaa{1:β}bbbbb    |
      bbbbb{1:β}ccccccccc^c    |
      {0:~                   }|
                          |
    ]])
    feed('gM')
    screen:expect([[
      aaaaaaaaaa{1:β}bbbbb    |
      ^bbbbb{1:β}cccccccccc    |
      {0:~                   }|
                          |
    ]])
    command('set conceallevel=3')
    screen:expect([[
      aaaaaaaaaabbbbb     |
      ^bbbbbcccccccccc     |
      {0:~                   }|
                          |
    ]])
    feed('$')
    screen:expect([[
      aaaaaaaaaabbbbb     |
      bbbbbccccccccc^c     |
      {0:~                   }|
                          |
    ]])
  end)
end)