neovim/test/functional/treesitter/utils_spec.lua
Riley Bruins 64847fbdc9 perf(treesitter): use child_containing_descendant() in is_ancestor()
**Problem:** `is_ancestor()` uses a slow, bottom-up parent lookup which
has performance pitfalls detailed in #28512.

**Solution:** Take `is_ancestor()` from $O(n^2)$ to $O(n)$ by
incorporating the use of the `child_containing_descendant()` function
2024-09-25 23:01:08 +02:00

53 lines
1.5 KiB
Lua

local t = require('test.testutil')
local n = require('test.functional.testnvim')()
local clear = n.clear
local insert = n.insert
local eq = t.eq
local exec_lua = n.exec_lua
before_each(clear)
describe('treesitter utils', function()
before_each(clear)
it('can find an ancestor', function()
insert([[
int main() {
int x = 3;
}]])
exec_lua(function()
local parser = vim.treesitter.get_parser(0, 'c')
local tree = parser:parse()[1]
local root = tree:root()
_G.ancestor = assert(root:child(0))
_G.child = assert(_G.ancestor:named_child(1))
_G.child_sibling = assert(_G.ancestor:named_child(2))
_G.grandchild = assert(_G.child:named_child(0))
end)
eq(true, exec_lua('return vim.treesitter.is_ancestor(_G.ancestor, _G.child)'))
eq(true, exec_lua('return vim.treesitter.is_ancestor(_G.ancestor, _G.grandchild)'))
eq(false, exec_lua('return vim.treesitter.is_ancestor(_G.child, _G.ancestor)'))
eq(false, exec_lua('return vim.treesitter.is_ancestor(_G.child, _G.child_sibling)'))
end)
it('can detect if a position is contained in a node', function()
exec_lua(function()
_G.node = {
range = function()
return 0, 4, 0, 8
end,
}
end)
eq(false, exec_lua('return vim.treesitter.is_in_node_range(node, 0, 3)'))
for i = 4, 7 do
eq(true, exec_lua('return vim.treesitter.is_in_node_range(node, 0, ...)', i))
end
-- End column exclusive
eq(false, exec_lua('return vim.treesitter.is_in_node_range(node, 0, 8)'))
end)
end)