Export events in readonly endpoints

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to the versioning scheme outlined in the [README.md](RE
 - Fixed an issue where `event.committed` was always equal to `true` in the block replay RPC endpoint
 - Added `result_hex` and `post_condition_aborted` to the block replay RPC endpoint
 - Added `--epoch <epoch_number>` flag to `clarity-cli` commands to specify the epoch context for evaluation.
+- Added the `events` array to readonly endpoints output.
 
 ### Fixed
 

clarity/src/vm/clarity.rs

@@ -204,6 +204,46 @@ pub trait ClarityConnection {
             (result, db)
         })
     }
+
+    #[allow(clippy::too_many_arguments)]
+    fn with_readonly_clarity_env_and_fill_events<F, R>(
+        &mut self,
+        mainnet: bool,
+        chain_id: u32,
+        sender: PrincipalData,
+        sponsor: Option<PrincipalData>,
+        cost_track: LimitedCostTracker,
+        events: &mut Vec<StacksTransactionEvent>,
+        to_do: F,
+    ) -> Result<R, VmExecutionError>
+    where
+        F: FnOnce(&mut Environment) -> Result<R, VmExecutionError>,
+    {
+        let epoch_id = self.get_epoch();
+        let clarity_version = ClarityVersion::default_for_epoch(epoch_id);
+        self.with_clarity_db_readonly_owned(|clarity_db| {
+            let initial_context =
+                ContractContext::new(QualifiedContractIdentifier::transient(), clarity_version);
+            let mut vm_env = OwnedEnvironment::new_cost_limited(
+                mainnet, chain_id, clarity_db, cost_track, epoch_id,
+            );
+            let result = vm_env
+                .execute_in_env(sender, sponsor, Some(initial_context), to_do)
+                .map(|(result, _, transaction_events)| {
+                    events.extend(transaction_events);
+                    result
+                });
+            // this expect is allowed, if the database has escaped this context, then it is no longer sane
+            //  and we must crash
+            #[allow(clippy::expect_used)]
+            let (db, _) = {
+                vm_env
+                    .destruct()
+                    .expect("Failed to recover database reference after executing transaction")
+            };
+            (result, db)
+        })
+    }
 }
 
 pub trait TransactionConnection: ClarityConnection {

clarity/src/vm/contexts.rs

@@ -231,6 +231,8 @@ pub struct GlobalContext<'a, 'hooks> {
     pub chain_id: u32,
     pub eval_hooks: Option<Vec<&'hooks mut dyn EvalHook>>,
     pub execution_time_tracker: ExecutionTimeTracker,
+    /// avoid events to be cleared too early while in read only mode
+    pub keep_event_batches: bool,
 }
 
 #[derive(Serialize, Deserialize, Clone)]
@@ -1261,7 +1263,17 @@ impl<'a, 'b, 'hooks> Environment<'a, 'b, 'hooks> {
         };
 
         if make_read_only {
+            let mut event_batches_clone = None;
+            if self.global_context.keep_event_batches {
+                event_batches_clone = Some(self.global_context.event_batches.clone());
+            }
+
             self.global_context.roll_back()?;
+
+            if let Some(event_batches_clone) = event_batches_clone {
+                self.global_context.event_batches = event_batches_clone
+            }
+
             result
         } else {
             self.global_context.handle_tx_result(result, allow_private)
@@ -1624,6 +1636,7 @@ impl<'a, 'hooks> GlobalContext<'a, 'hooks> {
             chain_id,
             eval_hooks: None,
             execution_time_tracker: ExecutionTimeTracker::NoTracking,
+            keep_event_batches: false,
         }
     }
 
@@ -1801,7 +1814,7 @@ impl<'a, 'hooks> GlobalContext<'a, 'hooks> {
         let out_batch = match self.event_batches.last_mut() {
             Some(tail_back) => {
                 tail_back.events.append(&mut event_batch.events);
-                None
+                Some(tail_back.clone())
             }
             None => Some(event_batch),
         };

docs/rpc/components/schemas/read-only-function-result.schema.yaml

@@ -24,3 +24,18 @@ oneOf:
       cause:
         type: string
         description: A string representing the cause of the error.
+      events:
+        type: array
+        description: Contract events generated by the call
+        items:
+          type: object
+          properties:
+            sender:
+              type: string
+              description: The contract address generating the event.
+            key:
+              type: string
+              description: Who generated the event (generally "print").
+            value:
+              type: string
+              description: Hex-encoded Clarity value of the event.