revert: "feat(treesitter): add foldtext with treesitter highlighting"

This reverts commit 9ce1623 in favor of #20750.

5 files changed, 2 insertions, 241 deletions

diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index a7c4e8147c..2212b9910b 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -123,7 +123,8 @@ BREAKING CHANGES IN HEAD                                    *news-breaking-dev*
 The following breaking changes were made during the development cycle to
 unreleased features on Nvim HEAD.
 
-• ...
+• Removed `vim.treesitter.foldtext` as transparent foldtext is now supported
+  https://github.com/neovim/neovim/pull/20750
 • ...
 
 ==============================================================================
@@ -223,8 +224,6 @@ The following new APIs and features were added.
   • |vim.treesitter.query.edit()| allows live editing of treesitter
     queries.
   • Improved error messages for query parsing.
-  • |vim.treesitter.foldtext()| applies treesitter highlighting to
-    foldtext.
 
 • |vim.ui.open()| opens URIs using the system default handler (macOS `open`,
   Windows `explorer`, Linux `xdg-open`, etc.)
diff --git a/runtime/doc/treesitter.txt b/runtime/doc/treesitter.txt
index 956b7d6ae5..0f4462b109 100644
--- a/runtime/doc/treesitter.txt
+++ b/runtime/doc/treesitter.txt
@@ -652,16 +652,6 @@ foldexpr({lnum})                                   *vim.treesitter.foldexpr()*
     Return: ~
         (`string`)
 
-foldtext()                                         *vim.treesitter.foldtext()*
-    Returns the highlighted content of the first line of the fold or falls
-    back to |foldtext()| if no treesitter parser is found. Can be set directly
-    to 'foldtext': >lua
-        vim.wo.foldtext = 'v:lua.vim.treesitter.foldtext()'
-<
-
-    Return: ~
-        (`{ [1]: string, [2]: string[] }[]|string`)
-
                                      *vim.treesitter.get_captures_at_cursor()*
 get_captures_at_cursor({winnr})
     Returns a list of highlight capture names under the cursor
diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index 3c91be7acf..9d96ab33fa 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -517,16 +517,4 @@ function M.foldexpr(lnum)
   return require('vim.treesitter._fold').foldexpr(lnum)
 end
 
---- Returns the highlighted content of the first line of the fold or falls back to |foldtext()|
---- if no treesitter parser is found. Can be set directly to 'foldtext':
----
---- ```lua
---- vim.wo.foldtext = 'v:lua.vim.treesitter.foldtext()'
---- ```
----
----@return { [1]: string, [2]: string[] }[] | string
-function M.foldtext()
-  return require('vim.treesitter._fold').foldtext()
-end
-
 return M
diff --git a/runtime/lua/vim/treesitter/_fold.lua b/runtime/lua/vim/treesitter/_fold.lua
index 735627d29f..d96cc966de 100644
--- a/runtime/lua/vim/treesitter/_fold.lua
+++ b/runtime/lua/vim/treesitter/_fold.lua
@@ -397,97 +397,4 @@ api.nvim_create_autocmd('OptionSet', {
     end
   end,
 })
-
----@package
----@return { [1]: string, [2]: string[] }[]|string
-function M.foldtext()
-  local foldstart = vim.v.foldstart
-  local bufnr = api.nvim_get_current_buf()
-
-  ---@type boolean, LanguageTree
-  local ok, parser = pcall(ts.get_parser, bufnr)
-  if not ok then
-    return vim.fn.foldtext()
-  end
-
-  local query = ts.query.get(parser:lang(), 'highlights')
-  if not query then
-    return vim.fn.foldtext()
-  end
-
-  local tree = parser:parse({ foldstart - 1, foldstart })[1]
-
-  local line = api.nvim_buf_get_lines(bufnr, foldstart - 1, foldstart, false)[1]
-  if not line then
-    return vim.fn.foldtext()
-  end
-
-  ---@type { [1]: string, [2]: string[], range: { [1]: integer, [2]: integer } }[] | { [1]: string, [2]: string[] }[]
-  local result = {}
-
-  local line_pos = 0
-
-  for id, node, metadata in query:iter_captures(tree:root(), 0, foldstart - 1, foldstart) do
-    local name = query.captures[id]
-    local start_row, start_col, end_row, end_col = node:range()
-
-    local priority = tonumber(metadata.priority or vim.highlight.priorities.treesitter)
-
-    if start_row == foldstart - 1 and end_row == foldstart - 1 then
-      -- check for characters ignored by treesitter
-      if start_col > line_pos then
-        table.insert(result, {
-          line:sub(line_pos + 1, start_col),
-          {},
-          range = { line_pos, start_col },
-        })
-      end
-      line_pos = end_col
-
-      local text = line:sub(start_col + 1, end_col)
-      table.insert(result, { text, { { '@' .. name, priority } }, range = { start_col, end_col } })
-    end
-  end
-
-  local i = 1
-  while i <= #result do
-    -- find first capture that is not in current range and apply highlights on the way
-    local j = i + 1
-    while
-      j <= #result
-      and result[j].range[1] >= result[i].range[1]
-      and result[j].range[2] <= result[i].range[2]
-    do
-      for k, v in ipairs(result[i][2]) do
-        if not vim.tbl_contains(result[j][2], v) then
-          table.insert(result[j][2], k, v)
-        end
-      end
-      j = j + 1
-    end
-
-    -- remove the parent capture if it is split into children
-    if j > i + 1 then
-      table.remove(result, i)
-    else
-      -- highlights need to be sorted by priority, on equal prio, the deeper nested capture (earlier
-      -- in list) should be considered higher prio
-      if #result[i][2] > 1 then
-        table.sort(result[i][2], function(a, b)
-          return a[2] < b[2]
-        end)
-      end
-
-      result[i][2] = vim.tbl_map(function(tbl)
-        return tbl[1]
-      end, result[i][2])
-      result[i] = { result[i][1], result[i][2] }
-
-      i = i + 1
-    end
-  end
-
-  return result
-end
-
 return M
diff --git a/test/functional/treesitter/fold_spec.lua b/test/functional/treesitter/fold_spec.lua
index ac9d227bb6..9428432f66 100644
--- a/test/functional/treesitter/fold_spec.lua
+++ b/test/functional/treesitter/fold_spec.lua
@@ -675,126 +675,3 @@ t2]])
     }
   end)
 end)
-
-describe('treesitter foldtext', function()
-  local test_text = [[
-void qsort(void *base, size_t nel, size_t width, int (*compar)(const void *, const void *))
-{
-  int width = INT_MAX, height = INT_MAX;
-  bool ext_widgets[kUIExtCount];
-  for (UIExtension i = 0; (int)i < kUIExtCount; i++) {
-    ext_widgets[i] = true;
-  }
-
-  bool inclusive = ui_override();
-  for (size_t i = 0; i < ui_count; i++) {
-    UI *ui = uis[i];
-    width = MIN(ui->width, width);
-    height = MIN(ui->height, height);
-    foo = BAR(ui->bazaar, bazaar);
-    for (UIExtension j = 0; (int)j < kUIExtCount; j++) {
-      ext_widgets[j] &= (ui->ui_ext[j] || inclusive);
-    }
-  }
-}]]
-  local screen
-
-  before_each(function()
-    screen = Screen.new(60, 5)
-    screen:set_default_attr_ids({
-      [0] = { foreground = Screen.colors.Blue, bold = true },
-      [1] = { foreground = Screen.colors.DarkBlue, background = Screen.colors.LightGray },
-      [2] = {
-        bold = true,
-        background = Screen.colors.LightGray,
-        foreground = Screen.colors.SeaGreen,
-      },
-      [3] = { foreground = Screen.colors.DarkCyan, background = Screen.colors.LightGray },
-      [4] = { foreground = Screen.colors.SlateBlue, background = Screen.colors.LightGray },
-      [5] = { bold = true, background = Screen.colors.LightGray, foreground = Screen.colors.Brown },
-      [6] = { background = Screen.colors.Red1 },
-      [7] = { foreground = Screen.colors.DarkBlue, background = Screen.colors.Red },
-      [8] = { foreground = Screen.colors.Brown, bold = true, background = Screen.colors.Red },
-      [9] = { foreground = Screen.colors.SlateBlue, background = Screen.colors.Red },
-      [10] = { bold = true },
-    })
-    screen:attach()
-  end)
-
-  it('displays highlighted content', function()
-    command([[set foldmethod=manual foldtext=v:lua.vim.treesitter.foldtext() updatetime=50]])
-    insert(test_text)
-    exec_lua([[vim.treesitter.get_parser(0, "c")]])
-
-    feed('ggVGzf')
-    screen:expect {
-      grid = [[
-      {4:^void}{1: }{3:qsort}{4:(void}{1: }{5:*}{3:base}{4:,}{1: }{4:size_t}{1: }{3:nel}{4:,}{1: }{4:size_t}{1: }{3:width}{4:,}{1: }{4:int}{1: }{4:(}{5:*}{3:compa}|
-      {0:~                                                           }|*3
-                                                                  |
-    ]],
-    }
-  end)
-
-  it('handles deep nested captures', function()
-    command([[set foldmethod=manual foldtext=v:lua.vim.treesitter.foldtext() updatetime=50]])
-    insert([[
-function FoldInfo.new()
-  return setmetatable({
-    start_counts = {},
-    stop_counts = {},
-    levels0 = {},
-    levels = {},
-  }, FoldInfo)
-end]])
-    exec_lua([[vim.treesitter.get_parser(0, "lua")]])
-
-    feed('ggjVGkzfgg')
-    screen:expect {
-      grid = [[
-      ^function FoldInfo.new()                                     |
-      {1:  }{5:return}{1: }{4:setmetatable({}{1:·····································}|
-      end                                                         |
-      {0:~                                                           }|
-                                                                  |
-    ]],
-    }
-
-    command('hi! Visual guibg=Red')
-    feed('GVgg')
-    screen:expect {
-      grid = [[
-      ^f{6:unction FoldInfo.new()}                                     |
-      {7:  }{8:return}{7: }{9:setmetatable({}{7:·····································}|
-      {6:end}                                                         |
-      {0:~                                                           }|
-      {10:-- VISUAL LINE --}                                           |
-    ]],
-    }
-
-    feed('10l<C-V>')
-    screen:expect {
-      grid = [[
-      {6:function F}^oldInfo.new()                                     |
-      {7:  }{8:return}{7: }{9:se}{4:tmetatable({}{1:·····································}|
-      {6:end}                                                         |
-      {0:~                                                           }|
-      {10:-- VISUAL BLOCK --}                                          |
-    ]],
-    }
-  end)
-
-  it('falls back to default', function()
-    command([[set foldmethod=manual foldtext=v:lua.vim.treesitter.foldtext()]])
-    insert(test_text)
-
-    feed('ggVGzf')
-    screen:expect {
-      grid = [[
-      {1:^+-- 19 lines: void qsort(void *base, size_t nel, size_t widt}|
-      {0:~                                                           }|*3
-                                                                  |
-    ]],
-    }
-  end)
-end)