build: enable lintlua for test/ dir

Problem:
Not all Lua code is checked by stylua. Automating code-style is an
important mechanism for reducing time spent on accidental
(non-essential) complexity.

Solution:
- Enable stylua for entire `test/` directory.
- Exclude these high-churn files until this issue is resolved: https://github.com/JohnnyMorganz/StyLua/issues/829
  ```
  test/functional/ui/decorations_spec.lua  | 3560 ++++++++++++++++++++++++++++++++++++----------------
  test/functional/ui/float_spec.lua        | 5826 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------
  test/functional/ui/multigrid_spec.lua    | 1349 ++++++++++++++------
  ```
- Make surgical changes to these files (or add `stylua: ignore` in some
  small scopes) to improve the result:
  ```
  test/functional/vimscript/msgpack_functions_spec.lua | 1414 +++++++++++++++------
  test/functional/api/buffer_spec.lua                  | 1389 +++++++++++----------
  test/functional/api/vim_spec.lua                     | 2740 +++++++++++++++++++++++-----------------
  ```
- These "high churn" files are NOT excluded because the changes are
  largely an improvement:
  ```
  test/functional/plugin/lsp_spec.lua      | 2198 ++++++++++++++++++---------------
  test/functional/plugin/shada_spec.lua    | 4078 +++++++++++++++++++++++++++++++++++-------------------------
  test/functional/ui/cmdline_spec.lua      | 1199 +++++++++++-------
  test/functional/ui/popupmenu_spec.lua    | 1267 +++++++++++--------
  test/functional/ui/messages_spec.lua     | 1643 +++++++++++++++---------
  ```
- TODO: how to check "all directories"? With `GLOB_DIRS *` and `/.deps/` (or
  `.deps/`) in `.styluaignore`, Lua code in `.deps/` is still checked...

4 files changed, 2279 insertions, 1815 deletions

diff --git a/test/functional/api/buffer_spec.lua b/test/functional/api/buffer_spec.lua
index b89101a5e7..e8fff7443d 100644
--- a/test/functional/api/buffer_spec.lua
+++ b/test/functional/api/buffer_spec.lua
@@ -23,16 +23,15 @@ describe('api/buf', function()
 
   -- access deprecated functions
   local function curbuf_depr(method, ...)
-    return request('buffer_'..method, 0, ...)
+    return request('buffer_' .. method, 0, ...)
   end
 
-
   describe('nvim_buf_set_lines, nvim_buf_line_count', function()
     it('deprecated forms', function()
       eq(1, curbuf_depr('line_count'))
-      curbuf_depr('insert', -1, {'line'})
+      curbuf_depr('insert', -1, { 'line' })
       eq(2, curbuf_depr('line_count'))
-      curbuf_depr('insert', -1, {'line'})
+      curbuf_depr('insert', -1, { 'line' })
       eq(3, curbuf_depr('line_count'))
       curbuf_depr('del_line', -1)
       eq(2, curbuf_depr('line_count'))
@@ -45,88 +44,88 @@ describe('api/buf', function()
     it("doesn't crash just after set undolevels=1 #24894", function()
       local buf = meths.create_buf(false, true)
       meths.buf_set_option(buf, 'undolevels', -1)
-      meths.buf_set_lines(buf, 0, 1, false, { })
+      meths.buf_set_lines(buf, 0, 1, false, {})
 
       assert_alive()
     end)
 
     it('cursor position is maintained after lines are inserted #9961', function()
       -- replace the buffer contents with these three lines.
-      request('nvim_buf_set_lines', 0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
+      request('nvim_buf_set_lines', 0, 0, -1, 1, { 'line1', 'line2', 'line3', 'line4' })
       -- Set the current cursor to {3, 2}.
-      curwin('set_cursor', {3, 2})
+      curwin('set_cursor', { 3, 2 })
 
       -- add 2 lines and delete 1 line above the current cursor position.
-      request('nvim_buf_set_lines', 0, 1, 2, 1, {"line5", "line6"})
+      request('nvim_buf_set_lines', 0, 1, 2, 1, { 'line5', 'line6' })
       -- check the current set of lines in the buffer.
-      eq({"line1", "line5", "line6", "line3", "line4"}, buffer('get_lines', 0, 0, -1, 1))
+      eq({ 'line1', 'line5', 'line6', 'line3', 'line4' }, buffer('get_lines', 0, 0, -1, 1))
       -- cursor should be moved below by 1 line.
-      eq({4, 2}, curwin('get_cursor'))
+      eq({ 4, 2 }, curwin('get_cursor'))
 
       -- add a line after the current cursor position.
-      request('nvim_buf_set_lines', 0, 5, 5, 1, {"line7"})
+      request('nvim_buf_set_lines', 0, 5, 5, 1, { 'line7' })
       -- check the current set of lines in the buffer.
-      eq({"line1", "line5", "line6", "line3", "line4", "line7"}, buffer('get_lines', 0, 0, -1, 1))
+      eq({ 'line1', 'line5', 'line6', 'line3', 'line4', 'line7' }, buffer('get_lines', 0, 0, -1, 1))
       -- cursor position is unchanged.
-      eq({4, 2}, curwin('get_cursor'))
+      eq({ 4, 2 }, curwin('get_cursor'))
 
       -- overwrite current cursor line.
-      request('nvim_buf_set_lines', 0, 3, 5, 1, {"line8", "line9"})
+      request('nvim_buf_set_lines', 0, 3, 5, 1, { 'line8', 'line9' })
       -- check the current set of lines in the buffer.
-      eq({"line1", "line5", "line6", "line8",  "line9", "line7"}, buffer('get_lines', 0, 0, -1, 1))
+      eq({ 'line1', 'line5', 'line6', 'line8', 'line9', 'line7' }, buffer('get_lines', 0, 0, -1, 1))
       -- cursor position is unchanged.
-      eq({4, 2}, curwin('get_cursor'))
+      eq({ 4, 2 }, curwin('get_cursor'))
 
       -- delete current cursor line.
       request('nvim_buf_set_lines', 0, 3, 5, 1, {})
       -- check the current set of lines in the buffer.
-      eq({"line1", "line5", "line6", "line7"}, buffer('get_lines', 0, 0, -1, 1))
+      eq({ 'line1', 'line5', 'line6', 'line7' }, buffer('get_lines', 0, 0, -1, 1))
       -- cursor position is unchanged.
-      eq({4, 2}, curwin('get_cursor'))
+      eq({ 4, 2 }, curwin('get_cursor'))
     end)
 
     it('cursor position is maintained in non-current window', function()
-      meths.buf_set_lines(0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
-      meths.win_set_cursor(0, {3, 2})
+      meths.buf_set_lines(0, 0, -1, 1, { 'line1', 'line2', 'line3', 'line4' })
+      meths.win_set_cursor(0, { 3, 2 })
       local win = meths.get_current_win()
       local buf = meths.get_current_buf()
 
       command('new')
 
-      meths.buf_set_lines(buf, 1, 2, 1, {"line5", "line6"})
-      eq({"line1", "line5", "line6", "line3", "line4"}, meths.buf_get_lines(buf, 0, -1, true))
-      eq({4, 2}, meths.win_get_cursor(win))
+      meths.buf_set_lines(buf, 1, 2, 1, { 'line5', 'line6' })
+      eq({ 'line1', 'line5', 'line6', 'line3', 'line4' }, meths.buf_get_lines(buf, 0, -1, true))
+      eq({ 4, 2 }, meths.win_get_cursor(win))
     end)
 
     it('cursor position is maintained in TWO non-current windows', function()
-      meths.buf_set_lines(0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
-      meths.win_set_cursor(0, {3, 2})
+      meths.buf_set_lines(0, 0, -1, 1, { 'line1', 'line2', 'line3', 'line4' })
+      meths.win_set_cursor(0, { 3, 2 })
       local win = meths.get_current_win()
       local buf = meths.get_current_buf()
 
       command('split')
-      meths.win_set_cursor(0, {4, 2})
+      meths.win_set_cursor(0, { 4, 2 })
       local win2 = meths.get_current_win()
 
       -- set current window to third one with another buffer
-      command("new")
+      command('new')
 
-      meths.buf_set_lines(buf, 1, 2, 1, {"line5", "line6"})
-      eq({"line1", "line5", "line6", "line3", "line4"}, meths.buf_get_lines(buf, 0, -1, true))
-      eq({4, 2}, meths.win_get_cursor(win))
-      eq({5, 2}, meths.win_get_cursor(win2))
+      meths.buf_set_lines(buf, 1, 2, 1, { 'line5', 'line6' })
+      eq({ 'line1', 'line5', 'line6', 'line3', 'line4' }, meths.buf_get_lines(buf, 0, -1, true))
+      eq({ 4, 2 }, meths.win_get_cursor(win))
+      eq({ 5, 2 }, meths.win_get_cursor(win2))
     end)
 
     it('line_count has defined behaviour for unloaded buffers', function()
       -- we'll need to know our bufnr for when it gets unloaded
       local bufnr = curbuf('get_number')
       -- replace the buffer contents with these three lines
-      request('nvim_buf_set_lines', bufnr, 0, -1, 1, {"line1", "line2", "line3", "line4"})
+      request('nvim_buf_set_lines', bufnr, 0, -1, 1, { 'line1', 'line2', 'line3', 'line4' })
       -- check the line count is correct
       eq(4, request('nvim_buf_line_count', bufnr))
       -- force unload the buffer (this will discard changes)
       command('new')
-      command('bunload! '..bufnr)
+      command('bunload! ' .. bufnr)
       -- line count for an unloaded buffer should always be 0
       eq(0, request('nvim_buf_line_count', bufnr))
     end)
@@ -135,12 +134,12 @@ describe('api/buf', function()
       -- we'll need to know our bufnr for when it gets unloaded
       local bufnr = curbuf('get_number')
       -- replace the buffer contents with these three lines
-      buffer('set_lines', bufnr, 0, -1, 1, {"line1", "line2", "line3", "line4"})
+      buffer('set_lines', bufnr, 0, -1, 1, { 'line1', 'line2', 'line3', 'line4' })
       -- confirm that getting lines works
-      eq({"line2", "line3"}, buffer('get_lines', bufnr, 1, 3, 1))
+      eq({ 'line2', 'line3' }, buffer('get_lines', bufnr, 1, 3, 1))
       -- force unload the buffer (this will discard changes)
       command('new')
-      command('bunload! '..bufnr)
+      command('bunload! ' .. bufnr)
       -- attempting to get lines now always gives empty list
       eq({}, buffer('get_lines', bufnr, 1, 3, 1))
       -- it's impossible to get out-of-bounds errors for an unloaded buffer
@@ -152,12 +151,12 @@ describe('api/buf', function()
       before_each(function()
         screen = Screen.new(20, 12)
         screen:set_default_attr_ids {
-          [1] = {bold = true, foreground = Screen.colors.Blue1};
-          [2] = {reverse = true, bold = true};
-          [3] = {reverse = true};
+          [1] = { bold = true, foreground = Screen.colors.Blue1 },
+          [2] = { reverse = true, bold = true },
+          [3] = { reverse = true },
         }
         screen:attach()
-        meths.buf_set_lines(0, 0, -1, 1, {"aaa", "bbb", "ccc", "ddd", "www", "xxx", "yyy", "zzz"})
+        meths.buf_set_lines(0, 0, -1, 1, { 'aaa', 'bbb', 'ccc', 'ddd', 'www', 'xxx', 'yyy', 'zzz' })
         meths.set_option_value('modified', false, {})
       end)
 
@@ -166,9 +165,10 @@ describe('api/buf', function()
         local buf = meths.get_current_buf()
 
         command('new | wincmd w')
-        meths.win_set_cursor(win, {8,0})
+        meths.win_set_cursor(win, { 8, 0 })
 
-        screen:expect{grid=[[
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -178,10 +178,12 @@ describe('api/buf', function()
           ^zzz                 |
           {2:[No Name]           }|
                               |
-        ]]}
+        ]],
+        }
 
-        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 0, 2, true, { 'aaabbb' })
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -191,11 +193,13 @@ describe('api/buf', function()
           ^zzz                 |
           {2:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- replacing topline keeps it the topline
-        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 4, true, { 'wwweeee' })
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -205,11 +209,13 @@ describe('api/buf', function()
           ^zzz                 |
           {2:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- inserting just before topline does not scroll up if cursor would be moved
-        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 3, true, { 'mmm' })
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -219,10 +225,13 @@ describe('api/buf', function()
           ^zzz                 |
           {2:[No Name] [+]       }|
                               |
-        ]], unchanged=true}
+        ]],
+          unchanged = true,
+        }
 
-        meths.win_set_cursor(0, {7, 0})
-        screen:expect{grid=[[
+        meths.win_set_cursor(0, { 7, 0 })
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -232,10 +241,12 @@ describe('api/buf', function()
           zzz                 |
           {2:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
-        meths.buf_set_lines(buf, 4, 4, true, {"mmmeeeee"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 4, 4, true, { 'mmmeeeee' })
+        screen:expect {
+          grid = [[
                               |
           {1:~                   }|*4
           {3:[No Name]           }|
@@ -245,7 +256,8 @@ describe('api/buf', function()
           ^yyy                 |
           {2:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
       end)
 
       it('of non-current window', function()
@@ -253,9 +265,10 @@ describe('api/buf', function()
         local buf = meths.get_current_buf()
 
         command('new')
-        meths.win_set_cursor(win, {8,0})
+        meths.win_set_cursor(win, { 8, 0 })
 
-        screen:expect{grid=[[
+        screen:expect {
+          grid = [[
           ^                    |
           {1:~                   }|*4
           {2:[No Name]           }|
@@ -265,10 +278,12 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name]           }|
                               |
-        ]]}
+        ]],
+        }
 
-        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 0, 2, true, { 'aaabbb' })
+        screen:expect {
+          grid = [[
           ^                    |
           {1:~                   }|*4
           {2:[No Name]           }|
@@ -278,11 +293,13 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- replacing topline keeps it the topline
-        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 4, true, { 'wwweeee' })
+        screen:expect {
+          grid = [[
           ^                    |
           {1:~                   }|*4
           {2:[No Name]           }|
@@ -292,11 +309,13 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- inserting just before topline scrolls up
-        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 3, true, { 'mmm' })
+        screen:expect {
+          grid = [[
           ^                    |
           {1:~                   }|*4
           {2:[No Name]           }|
@@ -306,7 +325,8 @@ describe('api/buf', function()
           yyy                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
       end)
 
       it('of split windows with same buffer', function()
@@ -314,10 +334,11 @@ describe('api/buf', function()
         local buf = meths.get_current_buf()
 
         command('split')
-        meths.win_set_cursor(win, {8,0})
-        meths.win_set_cursor(0, {1,0})
+        meths.win_set_cursor(win, { 8, 0 })
+        meths.win_set_cursor(0, { 1, 0 })
 
-        screen:expect{grid=[[
+        screen:expect {
+          grid = [[
           ^aaa                 |
           bbb                 |
           ccc                 |
@@ -330,10 +351,12 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name]           }|
                               |
-        ]]}
-        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
+        ]],
+        }
+        meths.buf_set_lines(buf, 0, 2, true, { 'aaabbb' })
 
-        screen:expect{grid=[[
+        screen:expect {
+          grid = [[
           ^aaabbb              |
           ccc                 |
           ddd                 |
@@ -346,11 +369,13 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- replacing topline keeps it the topline
-        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 4, true, { 'wwweeee' })
+        screen:expect {
+          grid = [[
           ^aaabbb              |
           ccc                 |
           ddd                 |
@@ -363,11 +388,13 @@ describe('api/buf', function()
           zzz                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
 
         -- inserting just before topline scrolls up
-        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
-        screen:expect{grid=[[
+        meths.buf_set_lines(buf, 3, 3, true, { 'mmm' })
+        screen:expect {
+          grid = [[
           ^aaabbb              |
           ccc                 |
           ddd                 |
@@ -380,20 +407,21 @@ describe('api/buf', function()
           yyy                 |
           {3:[No Name] [+]       }|
                               |
-        ]]}
+        ]],
+        }
       end)
     end)
 
     it('handles clearing out non-current buffer #24911', function()
-        local buf = meths.get_current_buf()
-        meths.buf_set_lines(buf, 0, -1, true, {"aaa", "bbb", "ccc"})
-        command("new")
+      local buf = meths.get_current_buf()
+      meths.buf_set_lines(buf, 0, -1, true, { 'aaa', 'bbb', 'ccc' })
+      command('new')
 
-        meths.buf_set_lines(0, 0, -1, true, {"xxx", "yyy", "zzz"})
+      meths.buf_set_lines(0, 0, -1, true, { 'xxx', 'yyy', 'zzz' })
 
-        meths.buf_set_lines(buf, 0, -1, true, {})
-        eq({"xxx", "yyy", "zzz"}, meths.buf_get_lines(0, 0, -1, true))
-        eq({''}, meths.buf_get_lines(buf, 0, -1, true))
+      meths.buf_set_lines(buf, 0, -1, true, {})
+      eq({ 'xxx', 'yyy', 'zzz' }, meths.buf_get_lines(0, 0, -1, true))
+      eq({ '' }, meths.buf_get_lines(buf, 0, -1, true))
     end)
   end)
 
@@ -431,8 +459,8 @@ describe('api/buf', function()
 
   describe('deprecated: {get,set}_line_slice', function()
     it('get_line_slice: out-of-bounds returns empty array', function()
-      curbuf_depr('set_line_slice', 0, 0, true, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, curbuf_depr('get_line_slice', 0, 2, true, true)) --sanity
+      curbuf_depr('set_line_slice', 0, 0, true, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, 2, true, true)) --sanity
 
       eq({}, curbuf_depr('get_line_slice', 2, 3, false, true))
       eq({}, curbuf_depr('get_line_slice', 3, 9, true, true))
@@ -442,37 +470,36 @@ describe('api/buf', function()
     end)
 
     it('set_line_slice: out-of-bounds extends past end', function()
-      curbuf_depr('set_line_slice', 0, 0, true, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, curbuf_depr('get_line_slice', 0, 2, true, true)) --sanity
+      curbuf_depr('set_line_slice', 0, 0, true, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, 2, true, true)) --sanity
 
-      eq({'c'}, curbuf_depr('get_line_slice', -1, 4, true, true))
-      eq({'a', 'b', 'c'}, curbuf_depr('get_line_slice', 0, 5, true, true))
-      curbuf_depr('set_line_slice', 4, 5, true, true, {'d'})
-      eq({'a', 'b', 'c', 'd'}, curbuf_depr('get_line_slice', 0, 5, true, true))
-      curbuf_depr('set_line_slice', -4, -5, true, true, {'e'})
-      eq({'e', 'a', 'b', 'c', 'd'}, curbuf_depr('get_line_slice', 0, 5, true, true))
+      eq({ 'c' }, curbuf_depr('get_line_slice', -1, 4, true, true))
+      eq({ 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, 5, true, true))
+      curbuf_depr('set_line_slice', 4, 5, true, true, { 'd' })
+      eq({ 'a', 'b', 'c', 'd' }, curbuf_depr('get_line_slice', 0, 5, true, true))
+      curbuf_depr('set_line_slice', -4, -5, true, true, { 'e' })
+      eq({ 'e', 'a', 'b', 'c', 'd' }, curbuf_depr('get_line_slice', 0, 5, true, true))
     end)
 
     it('works', function()
-      eq({''}, curbuf_depr('get_line_slice', 0, -1, true, true))
+      eq({ '' }, curbuf_depr('get_line_slice', 0, -1, true, true))
       -- Replace buffer
-      curbuf_depr('set_line_slice', 0, -1, true, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, curbuf_depr('get_line_slice', 0, -1, true, true))
-      eq({'b', 'c'}, curbuf_depr('get_line_slice', 1, -1, true, true))
-      eq({'b'}, curbuf_depr('get_line_slice', 1, 2, true, false))
+      curbuf_depr('set_line_slice', 0, -1, true, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, -1, true, true))
+      eq({ 'b', 'c' }, curbuf_depr('get_line_slice', 1, -1, true, true))
+      eq({ 'b' }, curbuf_depr('get_line_slice', 1, 2, true, false))
       eq({}, curbuf_depr('get_line_slice', 1, 1, true, false))
-      eq({'a', 'b'}, curbuf_depr('get_line_slice', 0, -1, true, false))
-      eq({'b'}, curbuf_depr('get_line_slice', 1, -1, true, false))
-      eq({'b', 'c'}, curbuf_depr('get_line_slice', -2, -1, true, true))
-      curbuf_depr('set_line_slice', 1, 2, true, false, {'a', 'b', 'c'})
-      eq({'a', 'a', 'b', 'c', 'c'}, curbuf_depr('get_line_slice', 0, -1, true, true))
-      curbuf_depr('set_line_slice', -1, -1, true, true, {'a', 'b', 'c'})
-      eq({'a', 'a', 'b', 'c', 'a', 'b', 'c'},
-        curbuf_depr('get_line_slice', 0, -1, true, true))
+      eq({ 'a', 'b' }, curbuf_depr('get_line_slice', 0, -1, true, false))
+      eq({ 'b' }, curbuf_depr('get_line_slice', 1, -1, true, false))
+      eq({ 'b', 'c' }, curbuf_depr('get_line_slice', -2, -1, true, true))
+      curbuf_depr('set_line_slice', 1, 2, true, false, { 'a', 'b', 'c' })
+      eq({ 'a', 'a', 'b', 'c', 'c' }, curbuf_depr('get_line_slice', 0, -1, true, true))
+      curbuf_depr('set_line_slice', -1, -1, true, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'a', 'b', 'c', 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, -1, true, true))
       curbuf_depr('set_line_slice', 0, -3, true, false, {})
-      eq({'a', 'b', 'c'}, curbuf_depr('get_line_slice', 0, -1, true, true))
+      eq({ 'a', 'b', 'c' }, curbuf_depr('get_line_slice', 0, -1, true, true))
       curbuf_depr('set_line_slice', 0, -1, true, true, {})
-      eq({''}, curbuf_depr('get_line_slice', 0, -1, true, true))
+      eq({ '' }, curbuf_depr('get_line_slice', 0, -1, true, true))
     end)
   end)
 
@@ -483,21 +510,25 @@ describe('api/buf', function()
 
     it('fails correctly when input is not valid', function()
       eq(1, api.curbufmeths.get_number())
-      eq([['replacement string' item contains newlines]],
-        pcall_err(bufmeths.set_lines, 1, 1, 2, false, {'b\na'}))
+      eq(
+        [['replacement string' item contains newlines]],
+        pcall_err(bufmeths.set_lines, 1, 1, 2, false, { 'b\na' })
+      )
     end)
 
     it("fails if 'nomodifiable'", function()
       command('set nomodifiable')
-      eq([[Buffer is not 'modifiable']],
-        pcall_err(api.bufmeths.set_lines, 1, 1, 2, false, {'a','b'}))
+      eq(
+        [[Buffer is not 'modifiable']],
+        pcall_err(api.bufmeths.set_lines, 1, 1, 2, false, { 'a', 'b' })
+      )
     end)
 
     it('has correct line_count when inserting and deleting', function()
       eq(1, line_count())
-      set_lines(-1, -1, true, {'line'})
+      set_lines(-1, -1, true, { 'line' })
       eq(2, line_count())
-      set_lines(-1, -1, true, {'line'})
+      set_lines(-1, -1, true, { 'line' })
       eq(3, line_count())
       set_lines(-2, -1, true, {})
       eq(2, line_count())
@@ -508,81 +539,80 @@ describe('api/buf', function()
     end)
 
     it('can get, set and delete a single line', function()
-      eq({''}, get_lines(0, 1, true))
-      set_lines(0, 1, true, {'line1'})
-      eq({'line1'}, get_lines(0, 1, true))
-      set_lines(0, 1, true, {'line2'})
-      eq({'line2'}, get_lines(0, 1, true))
+      eq({ '' }, get_lines(0, 1, true))
+      set_lines(0, 1, true, { 'line1' })
+      eq({ 'line1' }, get_lines(0, 1, true))
+      set_lines(0, 1, true, { 'line2' })
+      eq({ 'line2' }, get_lines(0, 1, true))
       set_lines(0, 1, true, {})
-      eq({''}, get_lines(0, 1, true))
+      eq({ '' }, get_lines(0, 1, true))
     end)
 
     it('can get a single line with strict indexing', function()
-      set_lines(0, 1, true, {'line1.a'})
+      set_lines(0, 1, true, { 'line1.a' })
       eq(1, line_count()) -- sanity
       eq('Index out of bounds', pcall_err(get_lines, 1, 2, true))
       eq('Index out of bounds', pcall_err(get_lines, -3, -2, true))
     end)
 
     it('can get a single line with non-strict indexing', function()
-      set_lines(0, 1, true, {'line1.a'})
+      set_lines(0, 1, true, { 'line1.a' })
       eq(1, line_count()) -- sanity
       eq({}, get_lines(1, 2, false))
       eq({}, get_lines(-3, -2, false))
     end)
 
     it('can set and delete a single line with strict indexing', function()
-      set_lines(0, 1, true, {'line1.a'})
-      eq('Index out of bounds', pcall_err(set_lines, 1, 2, true, {'line1.b'}))
-      eq('Index out of bounds', pcall_err(set_lines, -3, -2, true, {'line1.c'}))
-      eq({'line1.a'}, get_lines(0, -1, true))
+      set_lines(0, 1, true, { 'line1.a' })
+      eq('Index out of bounds', pcall_err(set_lines, 1, 2, true, { 'line1.b' }))
+      eq('Index out of bounds', pcall_err(set_lines, -3, -2, true, { 'line1.c' }))
+      eq({ 'line1.a' }, get_lines(0, -1, true))
       eq('Index out of bounds', pcall_err(set_lines, 1, 2, true, {}))
       eq('Index out of bounds', pcall_err(set_lines, -3, -2, true, {}))
-      eq({'line1.a'}, get_lines(0, -1, true))
+      eq({ 'line1.a' }, get_lines(0, -1, true))
     end)
 
     it('can set and delete a single line with non-strict indexing', function()
-      set_lines(0, 1, true, {'line1.a'})
-      set_lines(1, 2, false, {'line1.b'})
-      set_lines(-4, -3, false, {'line1.c'})
-      eq({'line1.c', 'line1.a', 'line1.b'}, get_lines(0, -1, true))
+      set_lines(0, 1, true, { 'line1.a' })
+      set_lines(1, 2, false, { 'line1.b' })
+      set_lines(-4, -3, false, { 'line1.c' })
+      eq({ 'line1.c', 'line1.a', 'line1.b' }, get_lines(0, -1, true))
       set_lines(3, 4, false, {})
       set_lines(-5, -4, false, {})
-      eq({'line1.c', 'line1.a', 'line1.b'}, get_lines(0, -1, true))
+      eq({ 'line1.c', 'line1.a', 'line1.b' }, get_lines(0, -1, true))
     end)
 
     it('can handle NULs', function()
-      set_lines(0, 1, true, {'ab\0cd'})
-      eq({'ab\0cd'}, get_lines(0, -1, true))
+      set_lines(0, 1, true, { 'ab\0cd' })
+      eq({ 'ab\0cd' }, get_lines(0, -1, true))
     end)
 
     it('works with multiple lines', function()
-      eq({''}, get_lines(0, -1, true))
+      eq({ '' }, get_lines(0, -1, true))
       -- Replace buffer
-      for _, mode in pairs({false, true}) do
-        set_lines(0, -1, mode, {'a', 'b', 'c'})
-        eq({'a', 'b', 'c'}, get_lines(0, -1, mode))
-        eq({'b', 'c'}, get_lines(1, -1, mode))
-        eq({'b'}, get_lines(1, 2, mode))
+      for _, mode in pairs({ false, true }) do
+        set_lines(0, -1, mode, { 'a', 'b', 'c' })
+        eq({ 'a', 'b', 'c' }, get_lines(0, -1, mode))
+        eq({ 'b', 'c' }, get_lines(1, -1, mode))
+        eq({ 'b' }, get_lines(1, 2, mode))
         eq({}, get_lines(1, 1, mode))
-        eq({'a', 'b'}, get_lines(0, -2, mode))
-        eq({'b'}, get_lines(1, -2, mode))
-        eq({'b', 'c'}, get_lines(-3, -1, mode))
-        set_lines(1, 2, mode, {'a', 'b', 'c'})
-        eq({'a', 'a', 'b', 'c', 'c'}, get_lines(0, -1, mode))
-        set_lines(-2, -1, mode, {'a', 'b', 'c'})
-        eq({'a', 'a', 'b', 'c', 'a', 'b', 'c'},
-          get_lines(0, -1, mode))
+        eq({ 'a', 'b' }, get_lines(0, -2, mode))
+        eq({ 'b' }, get_lines(1, -2, mode))
+        eq({ 'b', 'c' }, get_lines(-3, -1, mode))
+        set_lines(1, 2, mode, { 'a', 'b', 'c' })
+        eq({ 'a', 'a', 'b', 'c', 'c' }, get_lines(0, -1, mode))
+        set_lines(-2, -1, mode, { 'a', 'b', 'c' })
+        eq({ 'a', 'a', 'b', 'c', 'a', 'b', 'c' }, get_lines(0, -1, mode))
         set_lines(0, -4, mode, {})
-        eq({'a', 'b', 'c'}, get_lines(0, -1, mode))
+        eq({ 'a', 'b', 'c' }, get_lines(0, -1, mode))
         set_lines(0, -1, mode, {})
-        eq({''}, get_lines(0, -1, mode))
+        eq({ '' }, get_lines(0, -1, mode))
       end
     end)
 
     it('can get line ranges with non-strict indexing', function()
-      set_lines(0, -1, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, get_lines(0, -1, true)) --sanity
+      set_lines(0, -1, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, get_lines(0, -1, true)) --sanity
 
       eq({}, get_lines(3, 4, false))
       eq({}, get_lines(3, 10, false))
@@ -592,8 +622,8 @@ describe('api/buf', function()
     end)
 
     it('can get line ranges with strict indexing', function()
-      set_lines(0, -1, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, get_lines(0, -1, true)) --sanity
+      set_lines(0, -1, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, get_lines(0, -1, true)) --sanity
 
       eq('Index out of bounds', pcall_err(get_lines, 3, 4, true))
       eq('Index out of bounds', pcall_err(get_lines, 3, 10, true))
@@ -604,20 +634,20 @@ describe('api/buf', function()
     end)
 
     it('set_lines: out-of-bounds can extend past end', function()
-      set_lines(0, -1, true, {'a', 'b', 'c'})
-      eq({'a', 'b', 'c'}, get_lines(0, -1, true)) --sanity
+      set_lines(0, -1, true, { 'a', 'b', 'c' })
+      eq({ 'a', 'b', 'c' }, get_lines(0, -1, true)) --sanity
 
-      eq({'c'}, get_lines(-2, 5, false))
-      eq({'a', 'b', 'c'}, get_lines(0, 6, false))
-      eq('Index out of bounds', pcall_err(set_lines, 4, 6, true, {'d'}))
-      set_lines(4, 6, false, {'d'})
-      eq({'a', 'b', 'c', 'd'}, get_lines(0, -1, true))
-      eq('Index out of bounds', pcall_err(set_lines, -6, -6, true, {'e'}))
-      set_lines(-6, -6, false, {'e'})
-      eq({'e', 'a', 'b', 'c', 'd'}, get_lines(0, -1, true))
+      eq({ 'c' }, get_lines(-2, 5, false))
+      eq({ 'a', 'b', 'c' }, get_lines(0, 6, false))
+      eq('Index out of bounds', pcall_err(set_lines, 4, 6, true, { 'd' }))
+      set_lines(4, 6, false, { 'd' })
+      eq({ 'a', 'b', 'c', 'd' }, get_lines(0, -1, true))
+      eq('Index out of bounds', pcall_err(set_lines, -6, -6, true, { 'e' }))
+      set_lines(-6, -6, false, { 'e' })
+      eq({ 'e', 'a', 'b', 'c', 'd' }, get_lines(0, -1, true))
     end)
 
-    it("set_lines on alternate buffer does not access invalid line (E315)", function()
+    it('set_lines on alternate buffer does not access invalid line (E315)', function()
       feed_command('set hidden')
       insert('Initial file')
       command('enew')
@@ -637,8 +667,8 @@ describe('api/buf', function()
     it("set_lines of invisible buffer doesn't move cursor in current window", function()
       local screen = Screen.new(20, 5)
       screen:set_default_attr_ids({
-        [1] = {bold = true, foreground = Screen.colors.Blue1},
-        [2] = {bold = true},
+        [1] = { bold = true, foreground = Screen.colors.Blue1 },
+        [2] = { bold = true },
       })
       screen:attach()
 
@@ -646,7 +676,7 @@ describe('api/buf', function()
         Who would win?
         A real window
         with proper text]])
-      local buf = api.meths.create_buf(false,true)
+      local buf = api.meths.create_buf(false, true)
       screen:expect([[
         Who would win?      |
         A real window       |
@@ -655,7 +685,7 @@ describe('api/buf', function()
                             |
       ]])
 
-      api.meths.buf_set_lines(buf, 0, -1, true, {'or some', 'scratchy text'})
+      api.meths.buf_set_lines(buf, 0, -1, true, { 'or some', 'scratchy text' })
       feed('i') -- provoke redraw
       screen:expect([[
         Who would win?      |
@@ -671,32 +701,31 @@ describe('api/buf', function()
         visible buffer line 1
         line 2
       ]])
-      local hiddenbuf = api.meths.create_buf(false,true)
+      local hiddenbuf = api.meths.create_buf(false, true)
       command('vsplit')
       command('vsplit')
       feed('<c-w>l<c-w>l<c-w>l')
       eq(3, funcs.winnr())
       feed('<c-w>h')
       eq(2, funcs.winnr())
-      api.meths.buf_set_lines(hiddenbuf, 0, -1, true,
-                              {'hidden buffer line 1', 'line 2'})
+      api.meths.buf_set_lines(hiddenbuf, 0, -1, true, { 'hidden buffer line 1', 'line 2' })
       feed('<c-w>p')
       eq(3, funcs.winnr())
     end)
 
     it('set_lines on unloaded buffer #8659 #22670', function()
       local bufnr = curbuf('get_number')
-      meths.buf_set_lines(bufnr, 0, -1, false, {'a', 'b', 'c'})
+      meths.buf_set_lines(bufnr, 0, -1, false, { 'a', 'b', 'c' })
       meths.buf_set_name(bufnr, 'set_lines')
       finally(function()
         os.remove('set_lines')
       end)
       command('write!')
       command('new')
-      command('bunload! '..bufnr)
+      command('bunload! ' .. bufnr)
       local new_bufnr = funcs.bufnr('set_lines', true)
       meths.buf_set_lines(new_bufnr, 0, -1, false, {})
-      eq({''}, meths.buf_get_lines(new_bufnr, 0, -1, false))
+      eq({ '' }, meths.buf_get_lines(new_bufnr, 0, -1, false))
     end)
   end)
 
@@ -709,70 +738,69 @@ describe('api/buf', function()
       text
       ]])
 
-      eq({'hello foo!'}, get_lines(0, 1, true))
-
+      eq({ 'hello foo!' }, get_lines(0, 1, true))
 
       -- can replace a single word
-      set_text(0, 6, 0, 9, {'world'})
-      eq({'hello world!', 'text'}, get_lines(0, 2, true))
+      set_text(0, 6, 0, 9, { 'world' })
+      eq({ 'hello world!', 'text' }, get_lines(0, 2, true))
 
       -- can insert text
-      set_text(0, 0, 0, 0, {'well '})
-      eq({'well hello world!', 'text'}, get_lines(0, 2, true))
+      set_text(0, 0, 0, 0, { 'well ' })
+      eq({ 'well hello world!', 'text' }, get_lines(0, 2, true))
 
       -- can delete text
-      set_text(0, 0, 0, 5, {''})
-      eq({'hello world!', 'text'}, get_lines(0, 2, true))
+      set_text(0, 0, 0, 5, { '' })
+      eq({ 'hello world!', 'text' }, get_lines(0, 2, true))
 
       -- can replace with multiple lines
-      set_text(0, 6, 0, 11, {'foo', 'wo', 'more'})
-      eq({'hello foo', 'wo', 'more!', 'text'}, get_lines(0,  4, true))
+      set_text(0, 6, 0, 11, { 'foo', 'wo', 'more' })
+      eq({ 'hello foo', 'wo', 'more!', 'text' }, get_lines(0, 4, true))
 
       -- will join multiple lines if needed
-      set_text(0, 6, 3, 4, {'bar'})
-      eq({'hello bar'}, get_lines(0,  1, true))
+      set_text(0, 6, 3, 4, { 'bar' })
+      eq({ 'hello bar' }, get_lines(0, 1, true))
 
       -- can use negative line numbers
-      set_text(-2, 0, -2, 5, {'goodbye'})
-      eq({'goodbye bar', ''}, get_lines(0, -1, true))
+      set_text(-2, 0, -2, 5, { 'goodbye' })
+      eq({ 'goodbye bar', '' }, get_lines(0, -1, true))
 
-      set_text(-1, 0, -1, 0, {'text'})
-      eq({'goodbye bar', 'text'}, get_lines(0, 2, true))
+      set_text(-1, 0, -1, 0, { 'text' })
+      eq({ 'goodbye bar', 'text' }, get_lines(0, 2, true))
 
       -- can append to a line
-      set_text(1, 4, -1, 4, {' and', 'more'})
-      eq({'goodbye bar', 'text and', 'more'}, get_lines(0, 3, true))
+      set_text(1, 4, -1, 4, { ' and', 'more' })
+      eq({ 'goodbye bar', 'text and', 'more' }, get_lines(0, 3, true))
 
       -- can use negative column numbers
-      set_text(0, -5, 0, -1, {'!'})
-      eq({'goodbye!'}, get_lines(0, 1, true))
+      set_text(0, -5, 0, -1, { '!' })
+      eq({ 'goodbye!' }, get_lines(0, 1, true))
     end)
 
     it('works with undo', function()
-        insert([[
+      insert([[
         hello world!
         foo bar
         ]])
 
-        -- setting text
-        set_text(0, 0, 0, 0, {'well '})
-        feed('u')
-        eq({'hello world!'}, get_lines(0, 1, true))
+      -- setting text
+      set_text(0, 0, 0, 0, { 'well ' })
+      feed('u')
+      eq({ 'hello world!' }, get_lines(0, 1, true))
 
-        -- deleting text
-        set_text(0, 0, 0, 6, {''})
-        feed('u')
-        eq({'hello world!'}, get_lines(0, 1, true))
+      -- deleting text
+      set_text(0, 0, 0, 6, { '' })
+      feed('u')
+      eq({ 'hello world!' }, get_lines(0, 1, true))
 
-        -- inserting newlines
-        set_text(0, 0, 0