Describe init.vim
  function! s:clear()
    for key in s:sections
      unlet! g:airline_section_{key}
    endfor
  endfunction

  let s:sections = ['a', 'b', 'c', 'gutter', 'x', 'y', 'z', 'warning']
  call airline#init#bootstrap()

  Before each
    call s:clear()
    call airline#init#sections()
  End

  It section a should have mode, paste, spell, iminsert
    Assert Match(g:airline_section_a, 'mode')
    Assert Match(g:airline_section_a, 'paste')
    Assert Match(g:airline_section_a, 'spell')
    Assert Match(g:airline_section_a, 'iminsert')
  End

  It section b should be blank because no extensions are installed
    Assert Equals(g:airline_section_b, '')
  End

  It section c should be file and coc_status
    set noautochdir
    call airline#init#sections()
    Assert Equals(g:airline_section_c, '%<%f%m %#__accent_red#%{airline#util#wrap(airline#parts#readonly(),0)}%#__restore__#%#__accent_bold#%#__restore__#%#__accent_bold#%#__restore__#')
  End

  It section c should be path and coc_status
    set autochdir
    call s:clear()
    call airline#init#sections()
    Assert Equals(g:airline_section_c, '%<%F%m %#__accent_red#%{airline#util#wrap(airline#parts#readonly(),0)}%#__restore__#%#__accent_bold#%#__restore__#%#__accent_bold#%#__restore__#')
  End

  It section x should be filetype
    Assert Equals(g:airline_section_x, '%#__accent_bold#%#__restore__#%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#wrap(airline#parts#filetype(),0)}')
  End

  It section y should be fenc and ff
    Assert Equals(g:airline_section_y, '%{airline#util#wrap(airline#parts#ffenc(),0)}')
  End

  It section z should be line numbers
    Assert Match(g:airline_section_z, '%p%%')
    Assert Match(g:airline_section_z, '%l')
    Assert Match(g:airline_section_z, '%v')
  End

  It section gutter should be blank unless csv extension is installed
    " Note: the csv extension uses only the window local variable
    Assert Equals(g:airline_section_gutter, '%=')
  End

  It section warning should be blank
    Assert Match(g:airline_section_warning, '')
  End

  It should not redefine sections already defined
    for s in s:sections
      let g:airline_section_{s} = s
    endfor
    call airline#init#bootstrap()
    for s in s:sections
      Assert Equals(g:airline_section_{s}, s)
    endfor
  End

  It all default statusline extensions should be blank
    Assert Equals(airline#parts#get('ale_error_count').raw, '')
    Assert Equals(airline#parts#get('ale_warning_count').raw, '')
    Assert Equals(airline#parts#get('lsp_error_count').raw, '')
    Assert Equals(airline#parts#get('lsp_warning_count').raw, '')
    Assert Equals(airline#parts#get('nvimlsp_error_count').raw, '')
    Assert Equals(airline#parts#get('nvimlsp_warning_count').raw, '')
    Assert Equals(airline#parts#get('hunks').raw, '')
    Assert Equals(airline#parts#get('branch').raw, '')
    Assert Equals(airline#parts#get('eclim').raw, '')
    Assert Equals(airline#parts#get('neomake_error_count').raw, '')
    Assert Equals(airline#parts#get('neomake_warning_count').raw, '')
    Assert Equals(airline#parts#get('obsession').raw, '')
    Assert Equals(airline#parts#get('syntastic-err').raw, '')
    Assert Equals(airline#parts#get('syntastic-warn').raw, '')
    Assert Equals(airline#parts#get('tagbar').raw , '')
    Assert Equals(airline#parts#get('whitespace').raw, '')
    Assert Equals(airline#parts#get('windowswap').raw , '')
    Assert Equals(airline#parts#get('ycm_error_count').raw, '')
    Assert Equals(airline#parts#get('ycm_warning_count').raw, '')
    Assert Equals(airline#parts#get('languageclient_error_count').raw, '')
    Assert Equals(airline#parts#get('languageclient_warning_count').raw, '')
    Assert Equals(airline#parts#get('coc_status').raw, '')
    Assert Equals(airline#parts#get('coc_current_function').raw, '')
    Assert Equals(airline#parts#get('vista').raw, '')
    Assert Equals(airline#parts#get('coc_warning_count').raw, '')
    Assert Equals(airline#parts#get('coc_error_count').raw, '')
    Assert Equals(airline#parts#get('battery').raw, '')
  End

  it should not redefine parts already defined
    call airline#parts#define_raw('linenr', 'bar')
    call s:clear()
    call airline#init#sections()
    Assert Match(g:airline_section_z, 'bar')
  End
End