chore: minor simulator utils cleanup

Author: benesjan

yarn-project/pxe/src/pxe_service/pxe_service.ts

@@ -343,27 +343,21 @@ export class PXEService implements PXE {
   }
 
   /**
-   * Simulate an unconstrained transaction on the given contract, without considering constraints set by ACIR.
+   * Simulate an unconstrained function call on the given contract, without considering constraints set by ACIR.
    * The simulation parameters are fetched using ContractDataProvider and executed using AcirSimulator.
    * Returns the simulation result containing the outputs of the unconstrained function.
    *
-   * @param execRequest - The transaction request object containing the target contract and function data.
-   * @param scopes - The accounts whose notes we can access in this call. Currently optional and will default to all.
+   * @param call - The function call to execute.
+   * @param authWitnesses - Authentication witnesses required for the function call.
+   * @param scopes - Optional array of account addresses whose notes can be accessed in this call. Defaults to all
+   * accounts if not specified.
    * @returns The simulation result containing the outputs of the unconstrained function.
    */
-  async #simulateUnconstrained(execRequest: FunctionCall, authWitnesses?: AuthWitness[], scopes?: AztecAddress[]) {
-    const { to: contractAddress, selector: functionSelector } = execRequest;
-
+  async #simulateUnconstrained(call: FunctionCall, authWitnesses?: AuthWitness[], scopes?: AztecAddress[]) {
     this.log.debug('Executing unconstrained simulator...');
     try {
-      const result = await this.simulator.runUnconstrained(
-        execRequest,
-        contractAddress,
-        functionSelector,
-        authWitnesses ?? [],
-        scopes,
-      );
-      this.log.verbose(`Unconstrained simulation for ${contractAddress}.${functionSelector} completed`);
+      const result = await this.simulator.runUnconstrained(call, authWitnesses ?? [], scopes);
+      this.log.verbose(`Unconstrained simulation for ${call.to}.${call.selector} completed`);
 
       return result;
     } catch (err) {

yarn-project/simulator/src/private/simulator.ts

@@ -1,19 +1,19 @@
 import { Fr } from '@aztec/foundation/fields';
 import { type Logger, createLogger } from '@aztec/foundation/log';
 import type { AbiDecoded, FunctionCall } from '@aztec/stdlib/abi';
-import { FunctionSelector, FunctionType } from '@aztec/stdlib/abi';
+import { FunctionSelector, FunctionType, decodeFromAbi } from '@aztec/stdlib/abi';
 import type { AuthWitness } from '@aztec/stdlib/auth-witness';
 import { AztecAddress } from '@aztec/stdlib/aztec-address';
 import { CallContext, HashedValues, PrivateExecutionResult, TxExecutionRequest, collectNested } from '@aztec/stdlib/tx';
 
-import { createSimulationError } from '../common/errors.js';
+import { ExecutionError, createSimulationError, resolveAssertionMessageFromError } from '../common/errors.js';
+import { Oracle, extractCallStack, toACVMWitness, witnessMapToFields } from './acvm/index.js';
 import type { ExecutionDataProvider } from './execution_data_provider.js';
 import { ExecutionNoteCache } from './execution_note_cache.js';
 import { HashedValuesCache } from './hashed_values_cache.js';
 import { executePrivateFunction, verifyCurrentClassId } from './private_execution.js';
 import { PrivateExecutionOracle } from './private_execution_oracle.js';
 import type { SimulationProvider } from './providers/simulation_provider.js';
-import { executeUnconstrainedFunction } from './unconstrained_execution.js';
 import { UnconstrainedExecutionOracle } from './unconstrained_execution_oracle.js';
 
 /**
@@ -117,27 +117,26 @@ export class AcirSimulator {
 
   /**
    * Runs an unconstrained function.
-   * @param request - The transaction request.
-   * @param entryPointArtifact - The artifact of the entry point function.
-   * @param contractAddress - The address of the contract.
-   * @param scopes - The accounts whose notes we can access in this call. Currently optional and will default to all.
+   * @param call - The function call to execute.
+   * @param authwits - Authentication witnesses required for the function call.
+   * @param scopes - Optional array of account addresses whose notes can be accessed in this call. Defaults to all
+   * accounts if not specified.
+   * @returns A decoded ABI value containing the function's return data.
    */
   public async runUnconstrained(
-    request: FunctionCall,
-    contractAddress: AztecAddress,
-    selector: FunctionSelector,
+    call: FunctionCall,
     authwits: AuthWitness[],
     scopes?: AztecAddress[],
   ): Promise<AbiDecoded> {
-    await verifyCurrentClassId(contractAddress, this.executionDataProvider);
-    const entryPointArtifact = await this.executionDataProvider.getFunctionArtifact(contractAddress, selector);
+    await verifyCurrentClassId(call.to, this.executionDataProvider);
+    const entryPointArtifact = await this.executionDataProvider.getFunctionArtifact(call.to, call.selector);
 
     if (entryPointArtifact.functionType !== FunctionType.UNCONSTRAINED) {
       throw new Error(`Cannot run ${entryPointArtifact.functionType} function as unconstrained`);
     }
 
-    const context = new UnconstrainedExecutionOracle(
-      contractAddress,
+    const oracle = new UnconstrainedExecutionOracle(
+      call.to,
       authwits,
       [],
       this.executionDataProvider,
@@ -146,14 +145,29 @@ export class AcirSimulator {
     );
 
     try {
-      return await executeUnconstrainedFunction(
-        this.simulationProvider,
-        context,
-        entryPointArtifact,
-        contractAddress,
-        request.selector,
-        request.args,
-      );
+      this.log.verbose(`Executing unconstrained function ${entryPointArtifact.name}`, {
+        contract: call.to,
+        selector: call.selector,
+      });
+
+      const initialWitness = toACVMWitness(0, call.args);
+      const acirExecutionResult = await this.simulationProvider
+        .executeUserCircuit(initialWitness, entryPointArtifact, new Oracle(oracle))
+        .catch((err: Error) => {
+          err.message = resolveAssertionMessageFromError(err, entryPointArtifact);
+          throw new ExecutionError(
+            err.message,
+            {
+              contractAddress: call.to,
+              functionSelector: call.selector,
+            },
+            extractCallStack(err, entryPointArtifact.debug),
+            { cause: err },
+          );
+        });
+
+      const returnWitness = witnessMapToFields(acirExecutionResult.returnWitness);
+      return decodeFromAbi(entryPointArtifact.returnTypes, returnWitness);
     } catch (err) {
       throw createSimulationError(err instanceof Error ? err : new Error('Unknown error during private execution'));
     }

yarn-project/simulator/src/private/unconstrained_execution.test.ts

@@ -93,7 +93,7 @@ describe('Unconstrained Execution test suite', () => {
         returnTypes: artifact.returnTypes,
       };
 
-      const result = await acirSimulator.runUnconstrained(execRequest, contractAddress, FunctionSelector.empty(), []);
+      const result = await acirSimulator.runUnconstrained(execRequest, [], []);
 
       expect(result).toEqual(9n);
     }, 30_000);