# What's the best to test and debug grammars?
**URL:** https://discuss.codemirror.net/t/whats-the-best-to-test-and-debug-grammars/2542
**Category:** Lezer
**Created:** [July 26, 2020, 4:47pm UTC](https://discuss.codemirror.net/t/whats-the-best-to-test-and-debug-grammars/2542 "2020-07-26T16:47:38Z")
**Posts on this page:** 1
**Showing post:** 5
### Author:  [@grayen](https://discuss.codemirror.net/u/grayen)
#### Post date: [May 19, 2021, 12:17pm UTC](https://discuss.codemirror.net/t/whats-the-best-to-test-and-debug-grammars/2542/5 "2021-05-19T12:17:39Z")
I got asked how to debug `SyntaxNode` with my code, which is to get the underlying tree via `node.cursor.tree`, though now I have updated it to just also accept `TreeCursor` and `SyntaxNode`. And I had a length bug causing the range to be out of bounds, which the current code does not account for (`to` should default to `Infinity` rather than `input.length` to circumvent that). Rather than keep replying to this forum post with updates, I just made it into a public Gist:
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