test(token-2022/transfer-fee): assert fee config, balances and withheld amounts

[moviendome]

Summary

tokens/token-2022/transfer-fee runs the full fee lifecycle — initialize, mint, two transfers, harvest, withdraw, update — but never reads anything back. Six specs log a transaction signature and the seventh mints and checks nothing, so the suite passes with the fee at zero, the cap ignored, or the whole transfer withheld. The spec titled "fee limit by maximumFee" does not look at maximumFee.

This reads the mint and token accounts after each step and asserts the numbers the fixture implies (decimals 2, 100 bps, maximumFee = 1, 300 minted):

• after initialize: both authorities are the payer, withheldAmount is 0, older and newer fee are 100 bps / max 1
• after mint: sender holds 300
• after transfer 100: sender 200, recipient 99, recipient withheld 1
• after transfer 200: sender 0, recipient 298, recipient withheld 2 — 1% would be 2, the cap holds it to 1
• after harvest: recipient withheld 0, mint withheldAmount 2
• after withdraw: mint withheldAmount 0, sender holds 2
• after update to 0/0: newer fee is 0 bps / max 0 at epoch + 2, older fee still 100 bps / max 1

Reads use getMint, getAccount, getTransferFeeConfig and getTransferFeeAmount from the @solana/spl-token version already in the dependency set. No new dependencies; lockfile unchanged. Test bodies and the existing log lines are untouched; the assertions are appended to each spec.

Test plan

• anchor test at this commit: 7 passing.
• Red proof: set maximumFee to 3 in the initialize spec and rerun. The first transfer still passes (the cap is not reached at 100), then 4 failing: the cap spec (expected 297n to equal 298n), harvest and withdraw (3n vs 2n), and update (3n vs 1n). Restored to 1, back to 7 passing.
• pnpm check (prettier) clean.

AI use

I identified the gap while reading this example, chose the assertions and the expected numbers, and reviewed the diff and both test runs; Claude drafted the code and this description.

🤖 Generated with Claude Code

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge, although the existing non-blocking epoch-rollover finding remains only partially addressed.

Summary

• Verifies fee configuration and authorities after initialization.
• Checks sender, recipient, and withheld balances after minting and transfers.
• Confirms the maximum-fee cap, harvest, withdrawal, and fee-schedule update behavior.
• Attempts to make the activation-epoch assertion resilient to an epoch rollover.

_{Reviews (2) · Last reviewed commit: "test(token-2022/transfer-fee): read the ..."}