Allow mutable parameters in messages

[SkymanOne]

Summary

Closes #826

• [n] y/n | Does it introduce breaking changes?
• [n] y/n | Is it dependant on the specific version of cargo-contract or pallet-contracts?

Allows message to have mut parameters.

Description

Constructor already provides the ability to have mut parameters as the parameter idents are replaced with ink_binding_{n} during codegen. The main problem with messages occurring before had to do with the contract_ref call builder. when extracting the ident from pat for input binding during codegen, syn automatically includes mut keyword. The solution is to go down the AST of Pat and extract ident from there. This is what input_message_idents() function does.

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have added an entry to CHANGELOG.md
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been merged and published in downstream modules

[github-actions]

🦑 📈 ink! Example Contracts ‒ Changes Report 📉 🦑

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

Contract	Upstream Size (kB)	PR Size (kB)	Diff (kB)	Diff (%)	Change
basic-contract-caller	2.967	2.967	0	0	➖
basic-contract-caller/other-contract	1.337	1.337	0	0	➖
call-builder-return-value	8.735	8.735	0	0	➖
call-runtime	1.769	1.769	0	0	➖
conditional-compilation	1.209	1.209	0	0	➖
contract-storage	7.171	7.171	0	0	➖
contract-terminate	1.092	1.092	0	0	➖
contract-transfer	1.444	1.444	0	0	➖
custom-allocator	7.428	7.428	0	0	➖
dns	7.249	7.249	0	0	➖
e2e-call-runtime	1.058	1.058	0	0	➖
e2e-runtime-only-backend	1.635	1.635	0	0	➖
erc1155	13.962	13.968	0.006	0.0429738	📈
erc20	6.687	6.687	0	0	➖
erc721	9.64	9.64	0	0	➖
events	4.763	4.763	0	0	➖
flipper	1.393	1.393	0	0	➖
incrementer	1.221	1.221	0	0	➖
lang-err-integration-tests/call-builder-delegate	2.317	2.317	0	0	➖
lang-err-integration-tests/call-builder	4.847	4.847	0	0	➖
lang-err-integration-tests/constructors-return-value	1.773	1.773	0	0	➖
lang-err-integration-tests/contract-ref	4.328	4.328	0	0	➖
lang-err-integration-tests/integration-flipper	1.571	1.571	0	0	➖
mapping-integration-tests	7.685	7.685	0	0	➖
mother	9.508	12.544	3.036	31.931	📈
multi-contract-caller	5.924	5.924	0	0	➖
multi-contract-caller/accumulator	1.095	1.095	0	0	➖
multi-contract-caller/adder	1.669	1.669	0	0	➖
multi-contract-caller/subber	1.689	1.689	0	0	➖
multisig	21.471	21.471	0	0	➖
payment-channel	5.501	5.501	0	0	➖
sr25519-verification	0.865	0.865	0	0	➖
static-buffer	1.405	1.405	0	0	➖
trait-dyn-cross-contract-calls	2.466	2.466	0	0	➖
trait-dyn-cross-contract-calls/contracts/incrementer	1.305	1.305	0	0	➖
trait-erc20	7.063	7.063	0	0	➖
trait-flipper	1.209	1.209	0	0	➖
trait-incrementer	1.37	1.37	0	0	➖
upgradeable-contracts/delegator	2.908	2.908	0	0	➖
upgradeable-contracts/delegator/delegatee	1.369	1.369	0	0	➖
upgradeable-contracts/set-code-hash	1.464	1.464	0	0	➖
upgradeable-contracts/set-code-hash/updated-incrementer	1.443	1.443	0	0	➖
wildcard-selector	2.622	2.622	0	0	➖

Link to the run | Last update: Tue Nov 28 18:09:16 CET 2023

[codecov-commenter]

Codecov Report

Attention: 7 lines in your changes are missing coverage. Please review.

Comparison is base (d4c57a3) 53.23% compared to head (e2e23e1) 53.37%.
Report is 4 commits behind head on master.

Files	Patch %	Lines
crates/ink/codegen/src/generator/arg_list.rs	0.00%	5 Missing ⚠️
...odegen/src/generator/as_dependency/contract_ref.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2004      +/-   ##
==========================================
+ Coverage   53.23%   53.37%   +0.13%     
==========================================
  Files         220      220              
  Lines        6845     6884      +39     
==========================================
+ Hits         3644     3674      +30     
- Misses       3201     3210       +9     

☔ View full report in Codecov by Sentry.
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[ascjones]

LGTM. Would be nice to have a ui/pass test too for the specification, but I suppose it is covered by the unit test + integration test.

[SkymanOne]

LGTM. Would be nice to have a ui/pass test too for the specification, but I suppose it is covered by the unit test + integration test.

The unit test already covers that mut is parsed correctly. Everything else stays the same.

[ascjones]

LGTM. Would be nice to have a ui/pass test too for the specification, but I suppose it is covered by the unit test + integration test.

The unit test already covers that must is parsed correctly. Everything else stays the same.

Indeed it does, so fine without it. Just pointing out that for the other cases in the unit test there is also a ui test. Maybe overkill, up to you.