fix: avoid loading result on is_promise_success

near-sdk/src/environment/env.rs

@@ -12,7 +12,7 @@ use crate::mock::MockedBlockchain;
 use crate::types::{
     AccountId, Balance, BlockHeight, Gas, PromiseIndex, PromiseResult, PublicKey, StorageUsage,
 };
-use crate::GasWeight;
+use crate::{GasWeight, PromiseError};
 use near_sys as sys;
 
 const REGISTER_EXPECTED_ERR: &str =
@@ -594,13 +594,21 @@ pub fn promise_results_count() -> u64 {
 /// If the current function is invoked by a callback we can access the execution results of the
 /// promises that caused the callback.
 pub fn promise_result(result_idx: u64) -> PromiseResult {
-    match unsafe { sys::promise_result(result_idx, ATOMIC_OP_REGISTER) } {
-        0 => PromiseResult::NotReady,
-        1 => {
+    match promise_result_internal(result_idx) {
+        Err(PromiseError::NotReady) => PromiseResult::NotReady,
+        Ok(()) => {
             let data = expect_register(read_register(ATOMIC_OP_REGISTER));
             PromiseResult::Successful(data)
         }
-        2 => PromiseResult::Failed,
+        Err(PromiseError::Failed) => PromiseResult::Failed,
+    }
+}
+
+pub(crate) fn promise_result_internal(result_idx: u64) -> Result<(), PromiseError> {
+    match unsafe { sys::promise_result(result_idx, ATOMIC_OP_REGISTER) } {
+        0 => Err(PromiseError::NotReady),
+        1 => Ok(()),
+        2 => Err(PromiseError::Failed),
         _ => abort(),
     }
 }

near-sdk/src/utils/mod.rs

@@ -95,7 +95,8 @@ pub fn assert_one_yocto() {
 /// Returns true if promise was successful.
 /// Fails if called outside a callback that received 1 promise result.
 pub fn is_promise_success() -> bool {
-    promise_result_as_success().is_some()
+    require!(env::promise_results_count() == 1, "Contract expected a result on the callback");
+    env::promise_result_internal(0).is_ok()
 }
 
 /// Returns the result of the promise if successful. Otherwise returns None.