Add example debugging-strategies

[cmichi]

(1) Adds the possibility to set a feature to build a contract with during e2e tests: #[ink_e2e::test(features = ["debug-info"])]. This allows for emitting debug events in the contract, that can be checked for in testing.

(2) Adds a new contract example that illustrates:

• how to use a debug feature with your contract
• how to check for contract reverts and decode the error message
• how to access the tracing API and work with it

[github-actions]

🦑 📈 ink! Example Contracts ‒ Changes Report 📉 🦑

These are the results when building the integration-tests/* contracts from this branch with cargo-contract-contract and comparing them to ink! master:

Contract	Upstream Size (kB)	PR Size (kB)	Diff (kB)	Diff (%)	Change
call-builder-return-value	35.189	20.549	-14.64	-41.6039	📉
call-runtime	19.273	2.182	-17.091	-88.6785	📉
combined-extension	17.74	2.552	-15.188	-85.6144	📉
complex-storage-structures	32.609	4.792	-27.817	-85.3047	📉
conditional-compilation	14.379	1.45	-12.929	-89.9158	📉
contract-invocation	40.73	8.224	-32.506	-79.8085	📉
contract-invocation/contract1	15.632	1.859	-13.773	-88.1077	📉
contract-invocation/contract2	15.568	1.785	-13.783	-88.5342	📉
contract-invocation/virtual_contract	33.116	4.448	-28.668	-86.5684	📉
contract-invocation/virtual_contract_ver1	15.304	1.855	-13.449	-87.879	📉
contract-invocation/virtual_contract_ver2	15.318	1.867	-13.451	-87.8117	📉
contract-storage	32.029	17.953	-14.076	-43.9477	📉
contract-terminate	15.268	1.41	-13.858	-90.765	📉
contract-transfer	18.909	3.059	-15.85	-83.8225	📉
contract-xcm	56.69	27.206	-29.484	-52.0092	📉
cross-contract-calls	38.828	9.123	-29.705	-76.5041	📉
cross-contract-calls/other-contract	14.435	1.524	-12.911	-89.4423	📉
custom-allocator	16.58	3.014	-13.566	-81.8215	📉
custom-environment	16.516	2.091	-14.425	-87.3395	📉
dns	38.319	7.856	-30.463	-79.4984	📉
e2e-call-runtime	16.349	1.686	-14.663	-89.6874	📉
e2e-runtime-only-backend	17.014	2.253	-14.761	-86.758	📉
erc1155	54.511	19.629	-34.882	-63.9908	📉
erc20	40.069	9.497	-30.572	-76.2984	📉
erc721	42.183	10.976	-31.207	-73.98	📉
events	21.381	6.311	-15.07	-70.4831	📉
flipper	14.503	1.598	-12.905	-88.9816	📉
incrementer	14.61	1.289	-13.321	-91.1773	📉
lang-err/call-builder	37.35	8.647	-28.703	-76.8487	📉
lang-err/call-builder-delegate	31.814	3.361	-28.453	-89.4355	📉
lang-err/constructors-return-value	15.679	2.259	-13.42	-85.5922	📉
lang-err/contract-ref	39.623	7.464	-32.159	-81.1625	📉
lang-err/integration-flipper	14.959	1.811	-13.148	-87.8936	📉
lazyvec	33.695	4.86	-28.835	-85.5765	📉
mapping	39.293	9.536	-29.757	-75.731	📉
mother	26.636	13.737	-12.899	-48.4269	📉
multi-contract-caller	46.772	12.742	-34.03	-72.7572	📉
multi-contract-caller/accumulator	14.459	1.147	-13.312	-92.0672	📉
multi-contract-caller/adder	31.706	3.157	-28.549	-90.0429	📉
multi-contract-caller/subber	31.755	3.165	-28.59	-90.0331	📉
multisig	62.478	24.535	-37.943	-60.7302	📉
own-code-hash	30.636	2.23	-28.406	-92.721	📉
payment-channel	44.936	11.227	-33.709	-75.0156	📉
psp22-extension	23.734	7.44	-16.294	-68.6526	📉
rand-extension	18.82	3.448	-15.372	-81.6791	📉
runtime-call-contract	14.429	1.528	-12.901	-89.4102	📉
sol-cross-contract	21.238	5.475	-15.763	-74.2207	📉
sol-cross-contract/other-contract-sol	16.018	2.49	-13.528	-84.455	📉
sol_encoding	15.918	2.417	-13.501	-84.8159	📉
solidity-calls-flipper	37.39	7.588	-29.802	-79.7058	📉
sr25519-verification	13.979	0.95	-13.029	-93.2041	📉
static-buffer	16.308	2.498	-13.81	-84.6824	📉
storage-types	28.487	16.777	-11.71	-41.1065	📉
trait-dyn-cross-contract-calls	32.092	3.574	-28.518	-88.8633	📉
trait-dyn-cross-contract-calls/contracts/incrementer	14.534	1.588	-12.946	-89.0739	📉
trait-erc20	40.31	9.73	-30.58	-75.8621	📉
trait-incrementer	14.584	1.648	-12.936	-88.6999	📉
upgradeable-contracts/delegator	34.913	6.446	-28.467	-81.537	📉
upgradeable-contracts/delegator/delegatee	30.498	2.59	-27.908	-91.5076	📉
upgradeable-contracts/delegator/delegatee2	30.498	2.589	-27.909	-91.5109	📉
upgradeable-contracts/set-code-hash	15.068	1.498	-13.57	-90.0584	📉
upgradeable-contracts/set-code-hash-migration	15.084	1.498	-13.586	-90.0689	📉
upgradeable-contracts/set-code-hash-migration/migration	15.331	1.778	-13.553	-88.4026	📉
upgradeable-contracts/set-code-hash-migration/updated-incrementer	15.324	1.685	-13.639	-89.0042	📉
upgradeable-contracts/set-code-hash/updated-incrementer	15.051	1.455	-13.596	-90.3329	📉
wildcard-selector	16.579	2.773	-13.806	-83.274	📉

Link to the run | Last update: Mon Mar 31 15:15:33 CEST 2025