add tests for tabline

test/tabline.vim

@@ -0,0 +1,67 @@
+let s:suite = themis#suite('tabline')
+let s:assert = themis#helper('assert')
+
+function! s:suite.before()
+  let g:lightline = {}
+endfunction
+
+function! s:suite.before_each()
+  let g:lightline = {}
+  call lightline#init()
+  tabonly
+endfunction
+
+function! s:suite.tabline()
+  call s:assert.equals(&tabline, '%!lightline#tabline()')
+endfunction
+
+function! s:suite.tabline_enabled()
+  let g:lightline = { 'enable': { 'tabline': 1 } }
+  call lightline#init()
+  call s:assert.equals(&tabline, '%!lightline#tabline()')
+endfunction
+
+function! s:suite.tabline_disabled()
+  let g:lightline = { 'enable': { 'tabline': 0 } }
+  call lightline#init()
+  call s:assert.equals(&tabline, '')
+endfunction
+
+function! s:tab(number, active, last) abort
+  return '%' . a:number . 'T%{lightline#onetab(' . a:number . ',' . a:active . ')}' . (a:last ? '%T' : '')
+endfunction
+
+function! s:suite.onetab()
+  call s:assert.equals(lightline#tabs(), [[], [s:tab(1, 1, 1)], []])
+endfunction
+
+function! s:suite.tabnew()
+  tabnew
+  call s:assert.equals(lightline#tabs(), [[s:tab(1, 0, 0)], [s:tab(2, 1, 1)], []])
+endfunction
+
+function! s:suite.tabnew_tabnew()
+  tabnew
+  tabnew
+  call s:assert.equals(lightline#tabs(), [[s:tab(1, 0, 0), s:tab(2, 0, 0)], [s:tab(3, 1, 1)], []])
+endfunction
+
+function! s:suite.tabnew_tabfirst()
+  tabnew
+  tabfirst
+  call s:assert.equals(lightline#tabs(), [[], [s:tab(1, 1, 0)], [s:tab(2, 0, 1)]])
+endfunction
+
+function! s:suite.tabnew_tabnew_tabfirst()
+  tabnew
+  tabnew
+  tabfirst
+  call s:assert.equals(lightline#tabs(), [[], [s:tab(1, 1, 0)], [s:tab(2, 0, 0), s:tab(3, 0, 1)]])
+endfunction
+
+function! s:suite.tabnew_tabnew_tabprevious()
+  tabnew
+  tabnew
+  tabprevious
+  call s:assert.equals(lightline#tabs(), [[s:tab(1, 0, 0)], [s:tab(2, 1, 0)], [s:tab(3, 0, 1)]])
+endfunction