feat: improve scope detection and calculation

doc/indent_blankline.txt

@@ -439,6 +439,8 @@ config.scope                                                *ibl.config.scope*
                            this is to the right of the indent guide) and an
                            underline on the last line of the scope ending at
                            the exact end of the scope.
+                           Also activates exact highlighting of one line
+                           scopes.
 
                            Default: `false` ~
 

lua/ibl/init.lua

@@ -189,7 +189,7 @@ M.refresh = function(bufnr)
     local scope
     local scope_start_line, scope_end_line
     if not scope_disabled and config.scope.enabled then
-        scope = scp.get(bufnr, config)
+        scope = scp.get(bufnr, config, global_buffer_state[bufnr] or {})
         if scope and scope:start() >= 0 then
             local scope_start = scope:start()
             local scope_end = scope:end_()
@@ -432,10 +432,21 @@ M.refresh = function(bufnr)
         if config.scope.show_exact_scope then
             scope_col_start_draw = exact_scope_col_start - 1
             scope_show_end_cond = #whitespace_tbl >= scope_col_start_single
+
+            -- one line scopes
+            if scope_start and scope_end then
+                vim.api.nvim_buf_set_extmark(bufnr, namespace, row - 1, scope_col_start_draw, {
+                    end_col = scope_col_end,
+                    hl_group = scope_hl.underline,
+                    priority = config.scope.priority,
+                    strict = false,
+                })
+                inlay_hints.set(bufnr, row - 1, #whitespace, scope_hl.underline, scope_hl.underline)
+            end
         end
 
         -- Scope start
-        if config.scope.show_start and scope_start then
+        if config.scope.show_start and scope_start and not scope_end then
             vim.api.nvim_buf_set_extmark(bufnr, namespace, row - 1, scope_col_start_draw, {
                 end_col = #line,
                 hl_group = scope_hl.underline,
@@ -446,7 +457,7 @@ M.refresh = function(bufnr)
         end
 
         -- Scope end
-        if config.scope.show_end and scope_end and scope_show_end_cond then
+        if config.scope.show_end and scope_end and scope_show_end_cond and not scope_start then
             vim.api.nvim_buf_set_extmark(bufnr, namespace, row - 1, scope_col_start, {
                 end_col = scope_col_end,
                 hl_group = scope_hl.underline,

lua/ibl/scope.lua

@@ -4,10 +4,11 @@ local M = {}
 
 ---@param win number
 ---@return table<number, number>
-M.get_cursor_range = function(win)
+---@return table<number, number>
+M.get_cursor_ranges = function(win)
     local pos = vim.api.nvim_win_get_cursor(win)
     local row, col = pos[1] - 1, pos[2]
-    return { row, 0, row, col }
+    return { row, 0, row, col }, { row, col, row, col }
 end
 
 --- Takes a language tree and a range, and returns the child language tree for that range
@@ -34,8 +35,9 @@ end
 
 ---@param bufnr number
 ---@param config ibl.config.full
+---@param buffer_state { scope: TSNode?, left_offset: number, top_offset: number, tick: number }
 ---@return TSNode?
-M.get = function(bufnr, config)
+M.get = function(bufnr, config, buffer_state)
     local lang_tree_ok, lang_tree = pcall(vim.treesitter.get_parser, bufnr)
     if not lang_tree_ok or not lang_tree then
         return nil
@@ -51,7 +53,7 @@ M.get = function(bufnr, config)
         win = 0
     end
 
-    local range = M.get_cursor_range(win)
+    local range, cursor_range = M.get_cursor_ranges(win)
     lang_tree = M.language_for_range(lang_tree, range, config)
     if not lang_tree then
         return nil
@@ -62,10 +64,18 @@ M.get = function(bufnr, config)
         return nil
     end
 
-    local node = lang_tree:named_node_for_range(range, { bufnr = bufnr })
+    local node = lang_tree:named_node_for_range(cursor_range, { bufnr = bufnr })
     if not node then
         return nil
     end
+    if node:start() == node:end_() and not config.scope.show_exact_scope then
+        node = lang_tree:named_node_for_range(range, { bufnr = bufnr }) or node
+    end
+
+    -- if the scope didn't change, return node immediately
+    if buffer_state.scope and buffer_state.scope:equal(node) then
+        return node
+    end
 
     local excluded_node_types =
         utils.tbl_join(config.scope.exclude.node_type["*"] or {}, config.scope.exclude.node_type[lang] or {})