Fix FaucetFailedToBuildTx in smoke test

[ffakenz]

Our smoke test requires funds from the faucet to run. Once completed, it constructs a transaction to return the provided funds back to the faucet. To determine the amount of value to be returned, it subtracts a fee calculation from the remaining balance.

However, there is an issue with our fee calculation, causing the smoke test to fail with FaucetFailedToBuildTx {reason = TxBodyErrorAdaBalanceNegative (Coin (-176))}.

This PR aims to resolve the issue by removing the incorrect fee calculation and allowing the transaction to automatically balance itself during construction.

---

• CHANGELOG updated or not needed
• Documentation updated or not needed
• Haddocks updated or not needed
• No new TODOs introduced or explained herafter

[github-actions]

Transactions Costs

Sizes and execution budgets for Hydra protocol transactions. Note that unlisted parameters are currently using arbitrary values and results are not fully deterministic and comparable to previous runs.

Metadata
Generated at	2024-04-08 09:45:33.631303205 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	bccf2a430c016bc960fbf31b02694011cd399d20da8882aac9d33611	4110
νCommit	56b0f0b597150e619c76bed60683f3b1e42d7bc0685ed951b882bfc5	1975
νHead	86bff95ba20e9d1d1b34899a56d86bbacc9fed999260b27dcc92d128	9351
μHead	88f533cf67cd0fc93d7d9ccf0a8b1d69ffd1208a825efbebbc1d36ba*	4213

• The minting policy hash is only usable for comparison. As the script is parameterized, the actual script is unique per Head.

Cost of Init Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	4792	8.68	3.31	0.46
2	5000	10.72	4.10	0.49
3	5196	12.93	4.96	0.52
5	5597	16.66	6.39	0.58
10	6604	26.16	10.02	0.72
47	14044	97.83	37.53	1.83

Cost of Commit Transaction

This is using ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	594	10.24	4.04	0.29
2	784	13.88	5.64	0.34
3	969	17.66	7.29	0.39
5	1348	25.66	10.74	0.49
10	2276	48.19	20.30	0.79
19	3968	97.83	40.79	1.41

Cost of CollectCom Transaction

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	544	16.52	6.53	0.35
2	114	654	26.89	10.72	0.47
3	170	768	39.31	15.79	0.62
4	226	874	51.49	20.85	0.76
5	283	984	69.05	28.01	0.95
6	337	1099	87.37	35.57	1.16

Cost of Close Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	588	8.29	4.59	0.28
2	693	8.55	5.31	0.29
3	953	10.07	7.07	0.32
5	1158	11.15	8.88	0.36
10	2120	16.91	16.12	0.50
50	7959	49.33	62.17	1.35

Cost of Contest Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	624	8.65	4.73	0.28
2	859	9.83	6.20	0.31
3	910	10.03	6.85	0.32
5	1269	12.29	9.66	0.38
10	2052	16.87	15.75	0.49
50	7981	50.12	62.57	1.36

Cost of Abort Transaction

Some variation because of random mixture of still initial and already committed outputs.

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	4669	16.96	7.33	0.55
2	4789	27.80	12.11	0.67
3	4955	42.24	18.55	0.84
4	5016	56.58	24.80	1.01
5	5222	73.18	32.10	1.20
6	5337	98.56	43.38	1.49

Cost of FanOut Transaction

Involves spending head output and burning head tokens. Uses ada-only UTxO for better comparability.

Parties	UTxO	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
5	0	0	4628	7.85	3.28	0.44
5	1	57	4661	9.00	3.99	0.46
5	5	284	4796	13.70	6.88	0.52
5	10	569	4967	19.16	10.31	0.60
5	20	1138	5306	31.11	17.62	0.76
5	30	1709	5649	42.85	24.84	0.92
5	40	2278	5987	53.96	31.81	1.08
5	50	2845	6325	65.92	39.13	1.24
5	79	4492	7305	99.00	59.68	1.70

End-To-End Benchmark Results

This page is intended to collect the latest end-to-end benchmarks results produced by Hydra's Continuous Integration system from the latest master code.

Please take those results with a grain of salt as they are currently produced from very limited cloud VMs and not controlled hardware. Instead of focusing on the absolute results, the emphasis should be on relative results, eg. how the timings for a scenario evolve as the code changes.

Generated at 2024-04-08 09:49:19.141682899 UTC

Baseline Scenario

Number of nodes	3
Number of txs	9000
Avg. Confirmation Time (ms)	21.950689805
P99	106.40876387000053ms
P95	31.958029499999988ms
P50	19.349335ms
Number of Invalid txs	0

Baseline Scenario

Number of nodes	1
Number of txs	3000
Avg. Confirmation Time (ms)	4.172414273
P99	8.662175449999998ms
P95	5.4069274499999995ms
P50	3.961664ms
Number of Invalid txs	0

[github-actions]

Test Results

427 tests  ±0   419 ✅ ±0   15m 17s ⏱️ +44s
139 suites ±0     8 💤 ±0 
  5 files   ±0     0 ❌ ±0 

Results for commit ec430b2. ± Comparison against base commit 0fbcffe.

♻️ This comment has been updated with latest results.

[ch1bo]

The change is fine, the test assertions are / were confusing and I left some comments to maybe improve them (as we touch this code now).