Nova-Rewards

Nova Rewards Contract — Upgrade Guide

This guide covers the upgrade path for the standalone contracts/nova-rewards Soroban contract. The contract exposes two admin-only entrypoints for this process:

The nova-rewards Soroban contract supports in-place WASM upgrades via env.deployer().update_current_contract_wasm(). All instance storage (balances, admin, version counters) persists across upgrades.

Two storage keys track upgrade state:

Key	Description
MigrationVersion	Target version — incremented by upgrade()
MigratedVersion	Last completed migration — incremented by migrate()

migrate() is gated: it only runs when migrated_version < migration_version, so it is safe to call exactly once per upgrade and will panic if called again.

Because the contract stores its operational state in instance storage, balances, staking records, swap configuration, and the saved migration version remain available after a successful code swap.

Prerequisites

1. Install Rust and the wasm32-unknown-unknown target.
2. Install the Stellar CLI used by the repository deployment workflow.
3. Have the admin secret, or another signer authorized to act for the current admin.
4. Know the deployed contract ID for the nova-rewards instance you are updating.

# Rust + wasm32 target
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup target add wasm32-unknown-unknown

# Soroban CLI
cargo install --locked soroban-cli

Build the New Artifact

Step 1 — Add migration logic for the new version

In contracts/nova-rewards/src/lib.rs, inside migrate(), add a versioned block for any data transformations needed by the new release:

// Example: backfill a new field for version 2
if migration_version == 2 {
    // ... transform storage ...
}

The build artifact is:

Step 2 — Build the new WASM

cd contracts/nova-rewards
cargo build --release --target wasm32-unknown-unknown
# Output: ../../target/wasm32-unknown-unknown/release/nova_rewards.wasm

Use the optimized artifact if wasm-opt is available; otherwise use the raw release WASM.

Upload the WASM

Upload the artifact to the target network and capture the returned hash:

stellar contract upload \
  --wasm contracts/nova-rewards/target/wasm32-unknown-unknown/release/nova_rewards.optimized.wasm \
  --network-passphrase "Test SDF Network ; September 2015" \
  --rpc-url https://soroban-testnet.stellar.org \
  --source <ADMIN_SECRET>

This prints the 64-character hex WASM hash, e.g. abc123...def456.

Execute the Upgrade

Step 4 — Call upgrade()

stellar contract invoke \
  --network testnet \
  --source-account alice \
  --id <CONTRACT_ID> \
  -- upgrade \
  --new_wasm_hash <WASM_HASH_FROM_STEP_3>

What happens internally:

• MigrationVersion is incremented.
• The new WASM hash is stored under PendingWasmHash.
• env.deployer().update_current_contract_wasm(new_wasm_hash) swaps the bytecode.

Run the Migration

Step 5 — Call migrate()

stellar contract invoke \
  --network testnet \
  --source-account alice \
  --id <CONTRACT_ID> \
  -- migrate

What happens internally:

• Checks migrated_version < migration_version; panics with "migration already applied" if already done.
• Runs version-specific data transformations.
• Sets MigratedVersion = MigrationVersion.
• Emits upgraded event with (wasm_hash, migration_version).

---

Step 6 — Verify

# Both counters should match after a successful migrate()
soroban contract invoke --network testnet --id <CONTRACT_ID> -- get_migration_version
soroban contract invoke --network testnet --id <CONTRACT_ID> -- get_migrated_version

Confirm the upgraded event appears in the transaction record on the Stellar explorer.

1. Invoke get_migrated_version and confirm it matches CONTRACT_VERSION in contracts/nova-rewards/src/lib.rs.
2. Query representative balances with get_balance to confirm state survived the code swap.
3. Re-run contracts/nova-rewards/tests/upgrade.rs.
4. If the release touched swaps or staking, also run the swap and staking test suites.

Security Notes

• Only the admin address set during initialize may call upgrade or migrate.
• migrate() panics with "migration already applied" if called more than once per version.
• All instance storage (balances, admin, version counters) survives the WASM swap.

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Rollback

Soroban does not support automatic rollback. To revert:

1. Install the previous WASM and note its hash.
2. Call upgrade() with the old hash.
3. Call migrate() — add compensating data transformations if needed.