fix: flaky e2e_prover_node test (#8116)

Fix for the flakiness in e2e_prover_node caused by halting the default
prover node while it was building a proof.

Later edit: alternatively we could refactor the test to start proving
from the first unproven block instead of from the block the first tx
landed in.

yarn-project/end-to-end/src/e2e_prover_node.test.ts

@@ -9,7 +9,6 @@ import {
   SignerlessWallet,
   computeSecretHash,
   createDebugLogger,
-  retryUntil,
   sleep,
 } from '@aztec/aztec.js';
 import { StatefulTestContract, TestContract } from '@aztec/noir-contracts.js';
@@ -22,6 +21,7 @@ import {
   addAccounts,
   createSnapshotManager,
 } from './fixtures/snapshot_manager.js';
+import { waitForProvenChain } from './fixtures/utils.js';
 
 // Tests simple block building with a sequencer that does not upload proofs to L1,
 // and then follows with a prover node run (with real proofs disabled, but
@@ -85,6 +85,9 @@ describe('e2e_prover_node', () => {
   });
 
   it('submits three blocks, then prover proves the first two', async () => {
+    // wait for the proven chain to catch up with the pending chain before we shut off the prover node
+    await waitForProvenChain(ctx.aztecNode);
+
     // Stop the current prover node
     await ctx.proverNode.stop();
 
@@ -130,7 +133,7 @@ describe('e2e_prover_node', () => {
     await expect(proverNode.startProof(firstBlock, firstBlock)).rejects.toThrow(/behind the current world state/i);
 
     // Await until proofs get submitted
-    await retryUntil(async () => (await ctx.aztecNode.getProvenBlockNumber()) === secondBlock, 'proven', 60, 1);
+    await waitForProvenChain(ctx.aztecNode, secondBlock);
     expect(await ctx.aztecNode.getProvenBlockNumber()).toEqual(secondBlock);
 
     // Check that the prover id made it to the emitted event

yarn-project/end-to-end/src/fixtures/utils.ts

@@ -38,7 +38,7 @@ import {
   getContractClassFromArtifact,
 } from '@aztec/circuits.js';
 import { bufferAsFields } from '@aztec/foundation/abi';
-import { makeBackoff, retry } from '@aztec/foundation/retry';
+import { makeBackoff, retry, retryUntil } from '@aztec/foundation/retry';
 import {
   AvailabilityOracleAbi,
   AvailabilityOracleBytecode,
@@ -743,3 +743,14 @@ export async function deployCanonicalAuthRegistry(deployer: Wallet) {
   await expect(deployer.isContractClassPubliclyRegistered(canonicalAuthRegistry.contractClass.id)).resolves.toBe(true);
   await expect(deployer.getContractInstance(canonicalAuthRegistry.instance.address)).resolves.toBeDefined();
 }
+
+export async function waitForProvenChain(node: AztecNode, targetBlock?: number, timeoutSec = 60, intervalSec = 1) {
+  targetBlock ??= await node.getBlockNumber();
+
+  await retryUntil(
+    async () => (await node.getProvenBlockNumber()) >= targetBlock,
+    'proven chain status',
+    timeoutSec,
+    intervalSec,
+  );
+}