feat: allow rules to be treesitter context aware

When a rule is defined with the `:with_context()` method, has a
specified filetype, and is operating in a buffer with a treesitter
parser attached, the rule will only execute iff the treesitter language
at the cursor matches one of the filetypes specified in the initial rule
definition.

> If there are no specified filetypes, of there is no parser attached to
> the current buffer, the rule executes as normal

lua/nvim-autopairs.lua

@@ -1,5 +1,6 @@
 local log = require('nvim-autopairs._log')
 local utils = require('nvim-autopairs.utils')
+local ts_utils = require('nvim-autopairs.ts-utils')
 local basic_rule = require('nvim-autopairs.rules.basic')
 local api = vim.api
 local highlighter = nil
@@ -398,11 +399,24 @@ M.autopairs_map = function(bufnr, char)
         return char
     end
     local line = utils.text_get_current_line(bufnr)
-    local _, col = utils.get_cursor()
+    local row, col = utils.get_cursor()
     local new_text = ''
     local add_char = 1
     local rules = M.get_buf_rules(bufnr)
     for _, rule in pairs(rules) do
+        -- Rules executes as normal if no treesitter is attached to buffer or filetype not specified
+        if rule.filetypes and rule.is_context_aware and pcall(vim.treesitter.get_parser) then
+            local language_tree = ts_utils.get_language_tree_at_position({ row, col })
+            -- log.debug("cursor_position:" .. vim.inspect({ row, col }))
+            -- log.debug("language_tree:" .. vim.inspect(language_tree))
+            if language_tree then
+                local current_language_context = language_tree:lang()
+                -- log.debug("current_language_context:" .. current_language_context)
+                if not vim.tbl_contains(rule.filetypes, current_language_context) then
+                    return char
+                end
+            end
+        end
         if rule.start_pair then
             if char:match('<.*>') then
                 new_text = line

lua/nvim-autopairs/rule.lua

@@ -13,6 +13,7 @@ local Cond = require('nvim-autopairs.conds')
 --- @field is_multibyte boolean
 --- @field is_endwise boolean        only use on end_wise
 --- @field is_undo boolean           add break undo sequence
+--- @field is_context_aware boolean  only active in treesitter contexts specified in filetypes
 
 local Rule = setmetatable({}, {
     __call = function(self, ...)
@@ -50,6 +51,7 @@ function Rule.new(...)
         is_regex        = false,
         is_multibyte    = false,
         end_pair_length = nil,
+        is_context_aware = false,
     }, opt) or {}
 
     ---@param rule Rule
@@ -148,6 +150,11 @@ function Rule:set_end_pair_length(length)
     return self
 end
 
+function Rule:with_context()
+    self.is_context_aware = true
+    return self
+end
+
 function Rule:with_move(cond)
     if self.move_cond == nil then self.move_cond = {} end
     table.insert(self.move_cond, cond)

lua/nvim-autopairs/ts-utils.lua

@@ -1,6 +1,18 @@
 local ts_get_node_text = vim.treesitter.get_node_text or vim.treesitter.query.get_node_text
 local M = {}
 
+--- Returns the language tree at the given position.
+---@return LanguageTree
+function M.get_language_tree_at_position(position)
+    local language_tree = vim.treesitter.get_parser()
+    language_tree:for_each_tree(function(_, tree)
+        if tree:contains(vim.tbl_flatten({ position, position })) then
+            language_tree = tree
+        end
+    end)
+    return language_tree
+end
+
 function M.get_tag_name(node)
   local tag_name = nil
   if node ~=nil then