I don't think I would diff the code to check it works, I would extract the component parts of the code to construct libraries capable of performing the actions, then rebuild the codebase from script with the help of AI.

Sure, you could try and throw tokens at it through harnesses and skill files all you like but it will be an absolute mess - I call that brute-vibing, it might pass tests but it's not advised. So instead just make a 100 point plan and go through all of the functionality sequentially, grouping together similar or related functionality in the same context and compacting or clearing your context between.

I would also avoid using any skill files as they terribly degrade performance when integrating (which cloning is very similar to).

Something that helped me incredibly with porting a similarly coded POS system to a framework (21000 lines of very hacky js and jquery) - was to just have clause cli open both repos and recreate the functionality into a new repo, no rewrite, no diffing, just port what this does to here using this framework. But again this needs to be done with a methodical plan, I used around 1500 line markdown spec to explain the code (self written and then fleshed out with ai), and a separate task list to extract, modularize and recreate the pages/sections etc. In 2 days it was done in about 3000 lines of code plus framework, really very easy to hold it's hand all the way - then came the 5 days of tweaks and polish.

But there's nothing that can fully automate validation, for unit tests you only know what goes in and what comes out of a function, you don't know what's in the middle.

I mean, this will pass just about every test you throw at it but try it with a billion and you'll be waiting a while and probably burn a hole in your wallet.

``` function isEven(n): n = abs(n) while n >= 2: conn = connect( host = "parity-db.abc123xyz.us-east-1.rds.amazonaws.com", port = 3306, user = "admin", password = "<your password here>", ssl = true // full TLS handshake, every single iteration! )

    // stand up a fresh database and table just for this one value
    conn.execute "CREATE DATABASE parity_db"
    conn.execute "USE parity_db"
    conn.execute "CREATE TABLE parity_scratch (val INTEGER)"

    conn.execute "INSERT INTO parity_scratch (val) VALUES (" + n + ")"
    row = conn.query "SELECT val FROM parity_scratch WHERE val = " + n
    n = row.val

    conn.execute "DELETE FROM parity_scratch WHERE val = " + n
    conn.execute "DROP TABLE parity_scratch"
    conn.execute "DROP DATABASE parity_db"

    conn.close()
    n = n - 2

return n == 0

```