fix: make simulations validate resulting tx by default (#8157)

Closes #7956.

This PR simply flips a switch to make all simulations fail by default if
the transaction is an invalid one. Previously it did not throw due to
wanting to minimize disruptions in the PR, but it seems like there were
not that many effects. The only exception is the e2e prover. These are
failing due to a prover verification, and I have made an issue for this
to be looked into.

yarn-project/aztec-node/src/aztec-node/server.ts

@@ -15,6 +15,7 @@ import {
   LogType,
   MerkleTreeId,
   NullifierMembershipWitness,
+  type ProcessedTx,
   type ProverConfig,
   PublicDataWitness,
   PublicSimulationOutput,
@@ -25,6 +26,7 @@ import {
   type TxHash,
   TxReceipt,
   TxStatus,
+  type TxValidator,
   partitionReverts,
 } from '@aztec/circuit-types';
 import {
@@ -762,7 +764,7 @@ export class AztecNodeService implements AztecNode {
     );
   }
 
-  public async isValidTx(tx: Tx): Promise<boolean> {
+  public async isValidTx(tx: Tx, isSimulation: boolean = false): Promise<boolean> {
     const blockNumber = (await this.blockSource.getBlockNumber()) + 1;
 
     const newGlobalVariables = await this.globalVariableBuilder.buildGlobalVariables(
@@ -775,12 +777,17 @@ export class AztecNodeService implements AztecNode {
     // These validators are taken from the sequencer, and should match.
     // The reason why `phases` and `gas` tx validator is in the sequencer and not here is because
     // those tx validators are customizable by the sequencer.
-    const txValidator = new AggregateTxValidator(
+    const txValidators: TxValidator<Tx | ProcessedTx>[] = [
       new DataTxValidator(),
       new MetadataTxValidator(newGlobalVariables),
       new DoubleSpendTxValidator(new WorldStateDB(this.worldStateSynchronizer.getLatest())),
-      new TxProofValidator(this.proofVerifier),
-    );
+    ];
+
+    if (!isSimulation) {
+      txValidators.push(new TxProofValidator(this.proofVerifier));
+    }
+
+    const txValidator = new AggregateTxValidator(...txValidators);
 
     const [_, invalidTxs] = await txValidator.validateTxs([tx]);
     if (invalidTxs.length > 0) {

yarn-project/aztec.js/src/contract/batch_call.ts

@@ -78,7 +78,7 @@ export class BatchCall extends BaseContractInteraction {
 
     const [unconstrainedResults, simulatedTx] = await Promise.all([
       Promise.all(unconstrainedCalls),
-      this.wallet.simulateTx(txRequest, true, options?.from),
+      this.wallet.simulateTx(txRequest, true, options?.from, options?.skipTxValidation),
     ]);
 
     const results: any[] = [];

yarn-project/circuit-types/src/interfaces/aztec-node.ts

@@ -327,8 +327,9 @@ export interface AztecNode {
    * made invalid by *other* transactions if e.g. they emit the same nullifiers, or come become invalid
    * due to e.g. the max_block_number property.
    * @param tx - The transaction to validate for correctness.
+   * @param isSimulation - True if the transaction is a simulated one without generated proofs. (Optional)
    */
-  isValidTx(tx: Tx): Promise<boolean>;
+  isValidTx(tx: Tx, isSimulation?: boolean): Promise<boolean>;
 
   /**
    * Updates the configuration of this node.

yarn-project/end-to-end/package.local.json

@@ -5,4 +5,4 @@
     "test": "LOG_LEVEL=${LOG_LEVEL:-verbose} DEBUG_COLORS=1 NODE_NO_WARNINGS=1 node --experimental-vm-modules ../node_modules/.bin/jest --testTimeout=300000 --forceExit",
     "test:unit": "NODE_NO_WARNINGS=1 node --experimental-vm-modules ../node_modules/.bin/jest src/fixtures"
   }
-}
+}

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

@@ -532,7 +532,7 @@ export class PXEService implements PXE {
     txRequest: TxExecutionRequest,
     simulatePublic: boolean,
     msgSender: AztecAddress | undefined = undefined,
-    skipTxValidation: boolean = true, // TODO(#7956): make the default be false
+    skipTxValidation: boolean = false,
     scopes?: AztecAddress[],
   ): Promise<SimulatedTx> {
     return await this.jobQueue.put(async () => {
@@ -542,7 +542,7 @@ export class PXEService implements PXE {
       }
 
       if (!skipTxValidation) {
-        if (!(await this.node.isValidTx(simulatedTx.tx))) {
+        if (!(await this.node.isValidTx(simulatedTx.tx, true))) {
           throw new Error('The simulated transaction is unable to be added to state and is invalid.');
         }
       }