utf-8 pairs may not be working

[Kaiser-Yang]

Description

In this code, it just map the last byte of the pair, when it comes to utf-8 pairs, such as "（" and "）", which are more than one byte. The mappings may be broken when there is no "keymap" or "keymap_end" set for the rule.

nvim-autopairs/lua/nvim-autopairs.lua

Lines 292 to 296 in 59bce2e

	if rule.key_map == '' then
	rule.key_map = rule.start_pair:sub(#rule.start_pair)
	end
	expr_map(rule.key_map)
	local key_end = rule.key_end or rule.end_pair:sub(1, 1)

Maybe a more graceful way to do this is to map the last chracter rather than the last byte when keymap and keymap_end is not set by users.

Minimal config

Maybe the minimal repro is to add a rule for "（" and "）" but not set "key_map" and "key_map_end"

[windwp]

you can use function "use_key" to set mapping key. https://github.com/windwp/nvim-autopairs/wiki/Rules-API

https://github.com/windwp/nvim-autopairs/blob/master/tests/nvim-autopairs_spec.lua#L568

[Kaiser-Yang]

you can use function "use_key" to set mapping key. https://github.com/windwp/nvim-autopairs/wiki/Rules-API

https://github.com/windwp/nvim-autopairs/blob/master/tests/nvim-autopairs_spec.lua#L568

The mappings may be broken when there is no "keymap" or "keymap_end" set for the rule. I just hope the default handler should be more graceful.