voting

Voting Contract Example

This example demonstrates a complex storage pattern in a Soroban smart contract, designed to showcase the capabilities of the soroban-debugger.

For information on how to contribute to this project, please see the CONTRIBUTING.md.

The contract implements a simple voting system where proposals can be created, voted on, and tallied. It uses persistent storage to track proposals and a map of votes for each proposal.

Functions

• create_proposal(creator: Address, id: u32, title: String): Creates a new proposal.
• vote(voter: Address, proposal_id: u32, support: bool): Casts a vote (yay or nay).
• tally(proposal_id: u32) -> (u32, u32): Returns the current vote count.
• close(creator: Address, proposal_id: u32): Closes the proposal for further voting.

How to Debug

This section provides a step-by-step guide on using soroban-debug to inspect the contract's execution and state.

1. Compile the Contract

First, compile the contract to WASM:

cargo build --target wasm32-unknown-unknown --release

The WASM file will be located at target/wasm32-unknown-unknown/release/voting_contract.wasm.

2. Run a Function with Debugging

Execute the create_proposal function and observe the initial state setup:

soroban-debug run \
  --contract target/wasm32-unknown-unknown/release/voting_contract.wasm \
  --function create_proposal \
  --args '["GDG7...123", 1, "Upgrade Protocol"]' \
  --verbose

3. Inspect Storage Diffs

After voting, use the debugger to see how the Votes map changes in storage. This is particularly useful for debugging complex data structures.

soroban-debug run \
  --contract target/wasm32-unknown-unknown/release/voting_contract.wasm \
  --function vote \
  --args '["GBK2...456", 1, true]' \
  --storage '{"Proposal(1)": {...}, "Votes(1)": {}}'

4. Interactive Tallying

Use the interactive mode to step through the tally function and watch the vote count increment:

soroban-debug interactive --contract target/wasm32-unknown-unknown/release/voting_contract.wasm

Once in the interactive TUI:

1. Use break tally to set a breakpoint at the start of the tally function.
2. Use step to execute instructions line by line.
3. Use inspect to view the values of yays and nays as they update.

Storage Patterns to Observe

• Persistent Storage: Proposals and vote maps are stored persistently.
• Nested Maps: The Votes key points to a Map<Address, bool>, demonstrating how the debugger handles nested data structures.
• Access Control: The close function demonstrates how require_auth() works and how to debug authentication failures.