token-js: Add sync version of getAssociatedTokenAddress

[charlie-amihan]

solana-program-library/token/js/src/state/mint.ts

Line 114 in 48fbb5b

export async function getAssociatedTokenAddress(

This references (async) PublicKey.findProgramAddress, which references (async) PublicKey.createProgramAddress...but I'm not sure why https://github.com/solana-labs/solana-web3.js/blob/d93efdf/src/publickey.ts#L146 needs to be async. I may be missing something! It would just be nice to be able to neatly call this synchronously in a test or whatnot without bubbling up async/await.

[joncinque]

You've stumbled on the exact issue -- since this relies on PublicKey.createProgramAddress, it must be async. If we land solana-labs/solana#23185 on the @solana/web3.js side, then we can add a sync version for this too.

[joncinque]

Now that web3.js has a sync version of createProgramAddress, we can add a sync version of getAssociatedTokenAddress

[dboures]

How often does the web3.js dependency get updated? I'd be happy to implement this but I don't want to sneak in an unwelcome dependency change, and it looks like we need at least web3.js version 1.40 (currently on 1.36) for this change (solana-labs/solana-web3.js@v1.39.1...v1.40.0).

[joncinque]

It's done as needed, so feel free to do the bump if needed!