add support for return data (#63)

fuzz/fixture/proto/invoke.proto

@@ -64,14 +64,17 @@ message InstrEffects {
     // Program return code. Zero is success, errors are non-zero.
     uint32 program_result = 3;
 
+    // The instruction return data.
+    bytes return_data = 4;
+
     // Copies of accounts that were provided to the instruction. May be in an
     // arbitrary order. The pubkey of each account is unique in this list. Each
     // account address must also be in the InstrContext.
-    repeated AcctState resulting_accounts = 4;
+    repeated AcctState resulting_accounts = 5;
 }
 
 // An instruction processing test fixture.
 message InstrFixture {
     InstrContext input = 1;
     InstrEffects output = 2;
-}
+}

fuzz/fixture/src/effects.rs

@@ -14,6 +14,7 @@ pub struct Effects {
     pub execution_time: u64,
     // Program return code. Zero is success, errors are non-zero.
     pub program_result: u32,
+    pub return_data: Vec<u8>,
     /// Resulting accounts with state, to be checked post-simulation.
     pub resulting_accounts: Vec<(Pubkey, AccountSharedData)>,
 }
@@ -24,6 +25,7 @@ impl From<ProtoEffects> for Effects {
             compute_units_consumed,
             execution_time,
             program_result,
+            return_data,
             resulting_accounts,
         } = value;
 
@@ -34,6 +36,7 @@ impl From<ProtoEffects> for Effects {
             compute_units_consumed,
             execution_time,
             program_result,
+            return_data,
             resulting_accounts,
         }
     }
@@ -45,6 +48,7 @@ impl From<Effects> for ProtoEffects {
             compute_units_consumed,
             execution_time,
             program_result,
+            return_data,
             resulting_accounts,
         } = value;
 
@@ -55,6 +59,7 @@ impl From<Effects> for ProtoEffects {
             compute_units_consumed,
             execution_time,
             program_result,
+            return_data,
             resulting_accounts,
         }
     }

harness/src/fuzz/firedancer.rs

@@ -169,6 +169,8 @@ fn build_fixture_effects(context: &FuzzContext, result: &InstructionResult) -> F
         }
     };
 
+    let return_data = result.return_data.clone();
+
     let modified_accounts = context
         .accounts
         .iter()
@@ -191,7 +193,7 @@ fn build_fixture_effects(context: &FuzzContext, result: &InstructionResult) -> F
         compute_units_available: context
             .compute_units_available
             .saturating_sub(result.compute_units_consumed),
-        return_data: Vec::new(), // TODO: Mollusk doesn't capture return data.
+        return_data,
     }
 }
 
@@ -210,6 +212,7 @@ fn parse_fixture_effects(
     };
 
     let program_result = raw_result.clone().into();
+    let return_data = effects.return_data.clone();
 
     let resulting_accounts = accounts
         .iter()
@@ -232,6 +235,7 @@ fn parse_fixture_effects(
             .compute_budget
             .compute_unit_limit
             .saturating_sub(effects.compute_units_available),
+        return_data,
         resulting_accounts,
     }
 }

harness/src/fuzz/mollusk.rs

@@ -56,6 +56,7 @@ impl From<&InstructionResult> for FuzzEffects {
     fn from(input: &InstructionResult) -> Self {
         let compute_units_consumed = input.compute_units_consumed;
         let execution_time = input.execution_time;
+        let return_data = input.return_data.clone();
 
         let program_result = match &input.program_result {
             ProgramResult::Success => 0,
@@ -69,6 +70,7 @@ impl From<&InstructionResult> for FuzzEffects {
             compute_units_consumed,
             execution_time,
             program_result,
+            return_data,
             resulting_accounts,
         }
     }
@@ -78,6 +80,7 @@ impl From<&FuzzEffects> for InstructionResult {
     fn from(input: &FuzzEffects) -> Self {
         let compute_units_consumed = input.compute_units_consumed;
         let execution_time = input.execution_time;
+        let return_data = input.return_data.clone();
 
         let raw_result = if input.program_result == 0 {
             Ok(())
@@ -94,6 +97,7 @@ impl From<&FuzzEffects> for InstructionResult {
             execution_time,
             program_result,
             raw_result,
+            return_data,
             resulting_accounts,
         }
     }

harness/src/lib.rs

@@ -217,6 +217,8 @@ impl Mollusk {
             }
         };
 
+        let return_data = transaction_context.get_return_data().1.to_vec();
+
         let resulting_accounts: Vec<(Pubkey, AccountSharedData)> = accounts
             .iter()
             .map(|(pubkey, account)| {
@@ -236,6 +238,7 @@ impl Mollusk {
             execution_time: timings.details.execute_us,
             program_result: invoke_result.clone().into(),
             raw_result: invoke_result,
+            return_data,
             resulting_accounts,
         }
     }

harness/src/result.rs

@@ -51,6 +51,8 @@ pub struct InstructionResult {
     pub program_result: ProgramResult,
     /// The raw result of the program's execution.
     pub raw_result: Result<(), InstructionError>,
+    /// The return data produced by the instruction, if any.
+    pub return_data: Vec<u8>,
     /// The resulting accounts after executing the instruction.
     ///
     /// This includes all accounts provided to the processor, in the order
@@ -66,6 +68,7 @@ impl Default for InstructionResult {
             execution_time: 0,
             program_result: ProgramResult::Success,
             raw_result: Ok(()),
+            return_data: vec![],
             resulting_accounts: vec![],
         }
     }
@@ -111,6 +114,15 @@ impl InstructionResult {
                         actual_result, check_result,
                     );
                 }
+                CheckType::ReturnData(return_data) => {
+                    let check_return_data = return_data;
+                    let actual_return_data = &self.return_data;
+                    assert_eq!(
+                        actual_return_data, check_return_data,
+                        "CHECK: return_data: got {:?}, expected {:?}",
+                        actual_return_data, check_return_data,
+                    );
+                }
                 CheckType::ResultingAccount(account) => {
                     let pubkey = account.pubkey;
                     let resulting_account = self
@@ -199,6 +211,7 @@ impl InstructionResult {
             b.resulting_accounts.len(),
             "resulting accounts length mismatch"
         );
+        assert_eq!(self.return_data, b.return_data, "return data mismatch");
         for (a, b) in self
             .resulting_accounts
             .iter()
@@ -217,6 +230,8 @@ enum CheckType<'a> {
     ExecutionTime(u64),
     /// Check the result code of the program's execution.
     ProgramResult(ProgramResult),
+    /// Check the return data produced by executing the instruction.
+    ReturnData(Vec<u8>),
     /// Check a resulting account after executing the instruction.
     ResultingAccount(AccountCheck<'a>),
 }
@@ -255,6 +270,11 @@ impl<'a> Check<'a> {
         Check::new(CheckType::ProgramResult(ProgramResult::UnknownError(error)))
     }
 
+    /// Check the return data produced by executing the instruction.
+    pub fn return_data(return_data: Vec<u8>) -> Self {
+        Check::new(CheckType::ReturnData(return_data))
+    }
+
     /// Check a resulting account after executing the instruction.
     pub fn account(pubkey: &Pubkey) -> AccountCheckBuilder {
         AccountCheckBuilder::new(pubkey)

harness/tests/fd_test_vectors.rs

@@ -106,10 +106,10 @@ fn test_load_firedancer_fixtures() {
                         loaded_fixture.output.compute_units_available,
                         generated_fixture.output.compute_units_available,
                     );
-                    // assert_eq!(
-                    //     loaded_fixture.output.return_data,
-                    //     generated_fixture.output.return_data,
-                    // );
+                    assert_eq!(
+                        loaded_fixture.output.return_data,
+                        generated_fixture.output.return_data,
+                    );
                 }
             });
     });