Enhance STM library readability - Golden tests

[curiecrypt]

Content

This PR includes "golden" (de)serialization tests for several core types in the mithril-stm crate, ensuring that their JSON representations remain stable and correct:

• BLS multi signature:
  • Proof of possession
  • Signature
  • Signing key
  • Verification key
• Participant:
  • Initializer
• Single signature:
  • Signature
  • Signature with registered party
• Aggregate signature:
  • Concatenation proof

Note

This is a preliminary work that will help avoid introducing breaking changes in the protocol when the fields of the structures are renamed.

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • CHANGELOG file is updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested

Issue(s)

Relates to #2568

[github-actions]

Test Results

    4 files  ± 0    164 suites  ±0   24m 9s ⏱️ +8s
2 204 tests + 9  2 204 ✅ + 9  0 💤 ±0  0 ❌ ±0 
6 787 runs  +27  6 787 ✅ +27  0 💤 ±0  0 ❌ ±0 

Results for commit 5dddb47. ± Comparison against base commit d7ce977.

This pull request removes 1 and adds 10 tests. Note that renamed tests count towards both.

mithril-stm ‑ aggregate_signature::signature::tests::aggregate_signature_type::golden_bytes_encoding_prefix

mithril-stm ‑ aggregate_signature::signature::tests::aggregate_signature_golden_concatenation::golden_conversions
mithril-stm ‑ aggregate_signature::signature::tests::aggregate_signature_type_golden::golden_bytes_encoding_prefix
mithril-stm ‑ bls_multi_signature::proof_of_possession::tests::golden::golden_conversions
mithril-stm ‑ bls_multi_signature::signature::tests::golden::golden_conversions
mithril-stm ‑ bls_multi_signature::signing_key::tests::golden::golden_conversions
mithril-stm ‑ bls_multi_signature::verification_key::tests::golden::golden_conversions
mithril-stm ‑ parameters::tests::golden::golden_conversions
mithril-stm ‑ participant::initializer::tests::golden::golden_conversions
mithril-stm ‑ single_signature::signature::tests::golden::golden_conversions
mithril-stm ‑ single_signature::signature_registered_party::tests::golden::golden_conversions

♻️ This comment has been updated with latest results.

[Copilot]

Pull Request Overview

This PR enhances the Mithril STM library by adding golden tests across multiple modules to improve readability and maintainability. Golden tests are a form of regression testing that validate serialization/deserialization behavior by comparing against expected JSON outputs.

Key changes include:

• Implementation of golden tests for cryptographic components and data structures
• Addition of PartialEq implementation for the Initializer struct
• Extension of test dependencies to include serde_json

Reviewed Changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
mithril-stm/src/single_signature/signature_registered_party.rs	Adds golden tests for SingleSignatureWithRegisteredParty serialization
mithril-stm/src/single_signature/signature.rs	Adds golden tests for SingleSignature serialization
mithril-stm/src/participant/initializer.rs	Implements PartialEq and adds golden tests for Initializer
mithril-stm/src/parameters.rs	Adds golden tests for Parameters serialization
mithril-stm/src/bls_multi_signature/verification_key.rs	Adds golden tests for BLS verification key serialization
mithril-stm/src/bls_multi_signature/signing_key.rs	Adds golden tests for BLS signing key serialization
mithril-stm/src/bls_multi_signature/signature.rs	Adds golden tests for BLS signature serialization
mithril-stm/src/bls_multi_signature/proof_of_possession.rs	Adds golden tests for BLS proof of possession serialization
mithril-stm/Cargo.toml	Adds serde_json as test dependency

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[jpraynaud]

LGTM 👍