Fix init option storage mismatch and add tests

contracts/vault/src/lib.rs

@@ -280,6 +280,11 @@ impl CalloraVault {
             return Err(VaultError::MinDepositExceedsMaxDeduct);
         }
 
+        let initial_balance_val = initial_balance.unwrap_or(0);
+        if initial_balance_val < 0 {
+            return Err(VaultError::InitialBalanceNegative);
+        }
+
         env.storage().instance().set(&DataKey::Owner, &owner);
         // The admin role defaults to the owner at initialization so the
         // timelocked lifecycle actions (pause / upgrade / sweep) and
@@ -291,10 +296,14 @@ impl CalloraVault {
             .set(&DataKey::UsdcToken, &usdc_token);
         env.storage()
             .instance()
-            .set(&DataKey::Balance, &initial_balance);
-        env.storage()
-            .instance()
-            .set(&DataKey::AuthorizedCaller, &authorized_caller);
+            .set(&DataKey::Balance, &initial_balance_val);
+
+        if let Some(ac) = authorized_caller {
+            env.storage()
+                .instance()
+                .set(&DataKey::AuthorizedCaller, &ac);
+        }
+
         env.storage()
             .instance()
             .set(&DataKey::MinDeposit, &min_dep_val);
@@ -312,7 +321,7 @@ impl CalloraVault {
         env.storage().instance().set(&DataKey::Paused, &false);
 
         env.events()
-            .publish((events::event_init(&env), events::event_version_v1(&env), owner.clone()), initial_balance);
+            .publish((events::event_init(&env), events::event_version_v1(&env), owner.clone()), initial_balance_val);
         Ok(())
     }
 

contracts/vault/src/test_init_hardening.rs

@@ -393,3 +393,34 @@ fn init_default_min_deposit_is_one() {
     );
     assert_eq!(meta.min_deposit, DEFAULT_MIN_DEPOSIT);
 }
+
+#[test]
+fn init_none_initial_balance_allows_deposit_and_deduct() {
+    let env = Env::default();
+    env.mock_all_auths();
+    let owner = Address::generate(&env);
+    let (_, client) = create_vault(&env);
+    let (usdc, _, usdc_admin) = create_usdc(&env, &owner);
+    let settlement = Address::generate(&env);
+
+    client.init(
+        &owner,
+        &usdc,
+        &None,
+        &Some(owner.clone()),
+        &Some(1),
+        &None,
+        &Some(1000),
+        &Some(settlement),
+    );
+
+    usdc_admin.mint(&owner, &100);
+
+    // Deposit 50
+    client.deposit(&owner, &50);
+    assert_eq!(client.balance(), 50);
+
+    // Deduct 20
+    client.deduct(&owner, &20, &123);
+    assert_eq!(client.balance(), 30);
+}