test: contract upgrade via update_current_contract_wasm (Closes #177)

Author: Ummi-001

test_fixtures/mock_v2/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "mock-v2"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+soroban-sdk = "27.0.0"

test_fixtures/mock_v2/src/lib.rs

@@ -0,0 +1,16 @@
+#![no_std]
+use soroban_sdk::{contract, contractimpl, Env, symbol_short};
+
+#[contract]
+pub struct BridgeletCoreV2;
+
+#[contractimpl]
+impl BridgeletCoreV2 {
+    pub fn v2_exclusive_feature(_env: Env) -> u32 {
+        100
+    }
+
+    pub fn get_base_reserve(env: Env) -> u32 {
+        env.storage().instance().get(&symbol_short!("Reserve")).unwrap_or(0)
+    }
+}

test_fixtures/mock_v2/src/test_upgrade.rs

@@ -0,0 +1,37 @@
+#![cfg(test)]
+use soroban_sdk::{testutils::Address as _, Address, Env};
+use crate::{BridgeletCore, BridgeletCoreClient}; 
+
+mod mock_v2 {
+    soroban_sdk::contractimport!(
+        file = "./test_fixtures/mock_v2/target/wasm32v1-none/release/mock_v2.wasm"
+    );
+}
+
+#[test]
+fn test_contract_upgrade_preserves_state_and_adds_feature() {
+    let env = Env::default();
+    env.mock_all_auths();
+
+    let admin = Address::generate(&env);
+    let contract_id = env.register(BridgeletCore, ());
+    let client = BridgeletCoreClient::new(&env, &contract_id);
+
+    client.initialize(&admin);
+    client.set_base_reserve(&5000);
+    
+    let reserve_before = client.get_base_reserve();
+    assert_eq!(reserve_before, 5000, "V1 state should be set correctly");
+
+    let v2_wasm_hash = env.deployer().upload_contract_wasm(mock_v2::WASM);
+
+    client.upgrade(&v2_wasm_hash);
+
+    let v2_client = mock_v2::Client::new(&env, &contract_id);
+    
+    let reserve_after = v2_client.get_base_reserve();
+    assert_eq!(reserve_after, 5000, "V2 must retain V1 state");
+
+    let new_val = v2_client.v2_exclusive_feature();
+    assert_eq!(new_val, 100, "V2 exclusive feature must be accessible");
+}