[Testing] collect_fee fee-rounds-to-zero branch untested - positive fee rate but amount too small to charge

[grantfox-oss]

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Labels: contracts, testing, Stellar Wave, rust

There's no test for the case where a positive fee rate rounds down to a zero fee.

collect_fee guards with if fee > 0 at lib.rs:669. When fee_rate_bps > 0 but amount * bps / 10_000 truncates to 0 (e.g. amount=1 at 200 bps), no transfer and no FeeCollectedEvent happen and the full amount is credited. The only zero-fee test sets fee_rate_bps=0, which is a different code path. We should cover the rounds-to-zero branch so the behavior is pinned down.

What the fix has to hold to

• Test the rounds-to-zero path specifically, not the fee_rate_bps==0 path (already covered)

Done when

• Test initializes with a nonzero fee rate and creates a stream with a tiny amount where the fee rounds to 0
• Asserts treasury balance is 0, deposited_amount equals the full amount, and no fee_collected event fired
• Tests + fmt pass, CI green

Where to start
Mainly a test in contracts/stream_contract/src/test.rs; lib.rs is listed in case the assertion surfaces something worth adjusting. Small test addition.

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[grantfox-oss]

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[kelvin1738-sys]

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