Rpc: Filter accounts with invalid mints from get_parsed_token_accounts

[CriesofCarrots]

Problem

Several token rpc endpoints can return mixed parsed and unparsed token accounts when jsonParsed encoding is requested: this happens if the token account's mint cannot be found or is not valid, resulting in a no mint_decimals error when account-decoder attempts to parse the account. Account-decoder then defaults to unparsed.

This is problematic for clients that would like to know all results will be in the same format.

Summary of Changes

• Filter accounts in get_parsed_token_accounts such that all accounts return are parsed. Users that want to access all accounts, regardless of mint validity, will need to use another encoding.

[CriesofCarrots]

@jstarry , the biggest question mark in my mind about this approach is whether to special-case getProgramAccounts. Right now, a getProgramAccounts request for the SPL Token program id + jsonParsed encoding will also filter out accounts without a valid Mint (uses the same method). Thoughts?

[codecov]

Codecov Report

Merging #11844 into master will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##           master   #11844   +/-   ##
=======================================
  Coverage    82.1%    82.1%           
=======================================
  Files         330      330           
  Lines       77588    77601   +13     
=======================================
+ Hits        63701    63735   +34     
+ Misses      13887    13866   -21     

[jstarry]

@jstarry , the biggest question mark in my mind about this approach is whether to special-case getProgramAccounts. Right now, a getProgramAccounts request for the SPL Token program id + jsonParsed encoding will also filter out accounts without a valid Mint (uses the same method). Thoughts?

@CriesofCarrots I could see a case either way but I'm in favor of filtering them out. Like you said: "users that want to access all accounts, regardless of mint validity, will need to use another encoding."

That being said, I think we should add a disclaimer to the docs that explains that invalid accounts will not be returned.

Pull request has been modified.

[mergify]

automerge label removed due to a CI failure