Add assert_with_error! macro

soroban-sdk/src/lib.rs

@@ -129,7 +129,30 @@ pub use soroban_sdk_macros::symbol;
 macro_rules! panic_error {
     ($env:expr, $error:expr) => {{
         $env.panic_error($error);
-        unreachable!()
+        unreachable!();
+    }};
+}
+
+/// Assert a condition and panic with the given error if it is false.
+///
+/// The first argument in the list must be a reference to an [Env].
+///
+/// The second argument is an expression that if resolves to `false` will cause
+/// a panic with the error in the third argument.
+///
+/// The third argument is an error value. The error value will be given to any
+/// calling contract.
+///
+/// Equivalent to `assert!`, but with an error value instead of a string. The
+/// error value will be given to any calling contract.
+///
+/// See [`contracterror`] for how to define an error type.
+#[macro_export]
+macro_rules! assert_error {
+    ($env:expr, $cond:expr, $error:expr) => {{
+        if !($cond) {
+            $crate::panic_error!($env, $error);
+        }
     }};
 }
 

soroban-sdk/src/tests.rs

@@ -1,6 +1,7 @@
 #![cfg(test)]
 
 mod contract_add_i32;
+mod contract_assert_error;
 mod contract_call_stack;
 mod contract_invoke;
 mod contract_invoker_account;

soroban-sdk/src/tests/contract_assert_error.rs

@@ -0,0 +1,43 @@
+use crate as soroban_sdk;
+use soroban_sdk::{contractimpl, xdr::ScStatusType, Env, Status};
+use soroban_sdk_macros::contracterror;
+
+pub struct Contract;
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Error {
+    Zero = 1,
+}
+
+#[contractimpl]
+impl Contract {
+    pub fn assert(env: Env, value: u32) -> u32 {
+        assert_error!(&env, value > 0, Error::Zero);
+        value
+    }
+}
+
+#[test]
+#[should_panic(expected = "Status(ContractError(1)")]
+fn test_invoke_expect_status() {
+    let e = Env::default();
+    let contract_id = e.register_contract(None, Contract);
+
+    ContractClient::new(&e, &contract_id).assert(&0);
+}
+
+#[test]
+fn test_try_invoke() {
+    let e = Env::default();
+    let contract_id = e.register_contract(None, Contract);
+
+    let res = ContractClient::new(&e, &contract_id).try_assert(&0);
+    assert_eq!(
+        res,
+        Err(Ok(Status::from_type_and_code(
+            ScStatusType::ContractError,
+            1,
+        )))
+    );
+}