MettaChain/PropChain-contract

Replace manual `unwrap`/`expect` in production contracts with graceful error propagation

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#742 opened on Jul 23, 2026

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 (4 comments) (0 reactions) (1 assignee)Rust (151 forks)auto 404
High ComplexityRustStellar Waveenhancementhelp wanted

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Description

Problem Statement

60+ instances of .unwrap()/.expect() in production code paths across governance, property-management, sanctions, prediction-market, etc.

Why it matters

An unwrap in a paid user path is a denial-of-service vector and a gas bomb on bug-fix deployments.

Technical Context

Replace each unwrap() with ? or a typed error variant. Reserve unwraps for #[cfg(test)].

Expected Outcome

grep -rE '\.unwrap\(\)|\.expect\(' contracts/*/src/lib.rs returns 0 lines outside #[cfg(test)].

Acceptance Criteria

  1. Production unwraps removed.
  2. Tests unchanged in count.
  3. Kani harness prove_no_panic_in_storage_round_trip.
  4. Stack-overflow review: deep recursion removed.

Implementation Notes

Branch-by-branch, smallest to largest. Add safe_unwrap! macro in propchain-traits.

Files or modules likely to be affected

Every contracts/**/src/lib.rs.

Dependencies

None.

Difficulty level

MEDIUM.

Estimated effort

L (~1–2 engineer-weeks).

Contributor guide

Research direction
Inspect each `.unwrap()` and `.expect()` call in production code in `contracts/**/src/lib.rs`, replace with `?` or custom error types using `safe unwrap!` macro, and ensure Kani harness passes.
Tech stack
rust
Domain
blockchain
Issue type
Refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Rust
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65