Trc20AssetBalance/RealTronGridApi.fetchTrc20Balance() read through
TronGrid's /v1/accounts/{address} REST endpoint - but a TRC-20 balance
lives entirely in the token contract's own storage, not the holder's
Account object. An address that has only ever received TRC-20 tokens
(never native TRX, never otherwise "activated" on-chain) has no Account
object at all, so /v1/accounts silently returns `data: []` for it
regardless of its real token balance, and the old code treated that the
same as a genuinely empty/zero account.
Found via a live test: a real wallet received 5 USDT-TRC20, the exchange
confirmed the transfer complete on-chain, but the app kept showing 0.
Independently verified live: /v1/accounts returned empty for the address,
while a direct balanceOf(address) contract call (triggerconstantcontract)
correctly returned 5000000.
Rewrote fetchTrc20Balance() to read via balanceOf(address) instead -
reuses the existing triggerConstantContract() call already used for TRC-20
transfer fee estimation, plus a new encodeBalanceOfParameters() ABI helper
alongside the existing transfer() one. Added a regression test pinned to
this exact real address/balance so this can't silently regress again.
Public TronGrid rate-limits aggressively, and this test now runs on
every PR (plus its own 8h schedule) - a bare 429 was failing runs for
a transient, infrastructure reason unrelated to code correctness. Add
exponential backoff retry instead of treating it as an accepted flake.
Also required-status-check balances_test.yml's run-tests job on main
now that both this and the wallet-utils phantom-asset fix are confirmed
clean - it was deliberately left optional until proven, per "don't
promise gates you haven't verified."
Tron is a REST API (TronGrid), not a Substrate runtime, so it never goes
through BalancesIntegrationTest's chainRegistry-based mechanism at all -
it had zero CI coverage. This exercises the exact TronGridApi the
production app uses for balance reads, via a standalone Retrofit client
(TronGridApi isn't exposed through a public feature API for tests to
reach through the DI graph).
Test account is the mainnet Founder's Tron address, verified live via
TronGrid's public API on 2026-07-09: 3,925.23 TRX native + 625,213.92
USDT-TRC20 - substantial real balances, not a guessed or empty account.
pezkuwichain