Distribute Rewards

[Birdmannn]

Reward Pool Implementation Summary

What Was Done

1. Add Approved Spender Function

Implemented add_approved_spender function in the reward-pool contract to whitelist contract addresses that can distribute rewards.

Key Features:

• Admin-only access control
• Validates admin authentication
• Stores spender addresses in persistent storage
• Emits SpenderAdded event

Files Modified:

• contracts/reward-pool/src/lib.rs - Added function implementation
• contracts/reward-pool/src/types.rs - Added Spender(Address) to DataKey enum
• contracts/reward-pool/src/test.rs - Added 5 comprehensive tests

2. Fixed Distribute Reward Function

Corrected the order of validation checks in distribute_reward to ensure proper error messages.

Fix Applied:

• Moved initialization check before spender authorization check
• Now panics with "Not initialized" when contract isn't initialized (instead of "Caller is not an authorized spender")

3. Fixed Test Issues

• Corrected StellarAssetClient initialization to use .address() method
• Fixed event assertion patterns for Soroban event structure
• All 16 tests now pass

4. Project Configuration

• Added .vscode/ to .gitignore
• Fixed workspace configuration to exclude contracts/target directory
• Explicitly listed workspace members to avoid rust-analyzer errors

5. CI Validation

• ✅ Formatting check passes (cargo fmt)
• ✅ Linting passes (cargo clippy)
• ✅ All tests pass (cargo test)

Test Coverage

add_approved_spender tests:

• Success case with event verification
• Not initialized error
• Unauthorized admin error
• Multiple spenders
• Duplicate spender handling

distribute_reward tests:

• Success case with token transfer
• Zero/negative amount validation
• Unauthorized spender rejection
• Not initialized error
• Multiple distributions
• Multiple spenders

This PR closes #22

[Kaylahray]

Arigato Sensei 🙋‍♀️🔥🔥