Show HN: Treepeat – Code similarity detection using Tree-sitter

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Show HN: Treepeat – Code similarity detection using Tree-sitter

by 91awebsi

treepeat is a tool that finds similarities in your codebase.

Find duplicate code blocks meaningful to the language (classes/functions), not just lines.

Find near-duplicates: ignore whitespace, strings, high level AST nodes such as function and names.

Find structurally similar code: anonymize identifiers, constants, etc.

Pull requests welcome: This is very much an proof of concept - I'm happy with it, but I haven't supported very many languages at present.

Languages supported: astro, bash, css, go, html, javascript, lua, markdown (plus codeblocks), python, sql, typescript, java, kotlin, rust, yaml

ryuuseijin
11d
This is what I wanted to help with duplicate code detection, which is now a real problem with agentic programming since the agent tends to duplicate helper functions a lot in bigger codebases.
I ended up writing my own tool [1] that uses vector search, which works but can be unusably slow in large codebases.
I will give this a shot.
[1]: https://github.com/ninjaxtools/slopdex
1. 91awebsi • OP
  018h
  ooh I'll give yours a shot - thanks for calling my project out on your readme!
  I was fortunate to have a contributor push me to consider optimizations a few months back, and it definitely helped improve the speed/memory metrics.
  I see the CLI knobs are somewhat similar ('min lines', 'thresholds'), however your 'search' is fascinating. I could see myself wondering "how much error handling is duplicated for HTTP responses?" and your tool would give me a start at an answer. Nice!
bradleyy
11d
Thanks for posting this; I'm very interested in finding similar chunks of code in an AST-ish fashion, and using tree-sitter seems perfect.
1. 91awebsi • OP
  018h
  I keep meaning to write a post for how this has worked for my projects, I think its been helpful.
  For active projects I setup a weekly-ish 'code audit' agent: it runs treepeat to find opportunities to refactor and bumps up enforced coverage numbers. Over time for some projects I lower the '--similarity' threshold to more broadly find similar structured code (potentially more ambitious refactoring)
Game_Ender
21d
Thank you for a README that is readable. It might have a bit of AI help but it’s concise and makes it clear how to use the tool.
1. anaqin
  021h
  I dunno… I’m finding myself yearning for some emojis, a dedicated marketing web site, and a bunch of incomprehensible paragraphs that lack any soul.
adityamishra241
01d
Nice approach. AST-level similarity seems much more useful than simple text matching.
[deleted]
03d
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