test(fast-inbox): gate L1->L2 message readiness on the PXE sync tip (A-1384)

The shared cross-chain readiness helper evaluated isL1ToL2MessageReady against the
default 'latest' tip while these suites anchor the PXE to 'checkpointed'. With per-block
inbox insertion the proposed chain reaches a message's consume-checkpoint before that
checkpoint is published, so readiness flipped true a checkpoint early and the private
consume simulated against a PXE that had not yet synced the message. Gate readiness on
the configured PXE sync tip instead.

Author: spalladino

yarn-project/end-to-end/src/single-node/cross-chain/cross_chain_messaging_test.ts

@@ -21,6 +21,7 @@ import { TestERC20Abi, TestERC20Bytecode, TokenPortalAbi, TokenPortalBytecode }
 import { TokenContract } from '@aztec/noir-contracts.js/Token';
 import { TokenBridgeContract } from '@aztec/noir-contracts.js/TokenBridge';
 import type { PXEConfig } from '@aztec/pxe/server';
+import type { BlockTag } from '@aztec/stdlib/block';
 import { getEpochAtSlot } from '@aztec/stdlib/epoch-helpers';
 import type { AztecNodeAdmin } from '@aztec/stdlib/interfaces/client';
 
@@ -109,6 +110,17 @@ export class CrossChainMessagingTest extends SingleNodeTestContext {
     this.requireEpochProven = opts.startProverNode ?? false;
   }
 
+  /**
+   * Chain tip the PXE syncs to. L1→L2 message readiness must be evaluated against this tip rather than
+   * the default `'latest'`: with per-block inbox insertion the proposed chain reaches a message's
+   * checkpoint before that checkpoint is published, so a `'latest'` readiness check flips true while a
+   * PXE anchored to `'checkpointed'` (or `'proven'`) has not yet synced the block the consuming tx will
+   * anchor to. Defaults to `'latest'` so suites that do not pin a sync tip keep their semantics.
+   */
+  get pxeSyncChainTip(): BlockTag {
+    return this.pxeOpts.syncChainTip ?? 'latest';
+  }
+
   override async setup(opts: SingleNodeTestOpts = {}, pxeOpts: Partial<PXEConfig> = {}) {
     this.logger.info('Setting up cross chain messaging test');
     // Recompute requireEpochProven from the merged options so per-call startProverNode is honored.

yarn-project/end-to-end/src/single-node/cross-chain/message_test_helpers.ts

@@ -107,7 +107,7 @@ export function createL1ToL2MessageHelpers(deps: L1ToL2MessageHelperDeps): L1ToL
           aztecNode.getCheckpointNumber(),
         ]);
         const witness = await aztecNode.getL1ToL2MessageMembershipWitness('latest', msgHash);
-        const isReady = await isL1ToL2MessageReady(aztecNode, msgHash);
+        const isReady = await isL1ToL2MessageReady(aztecNode, msgHash, t.pxeSyncChainTip);
         log.info(
           `Block is ${blockNumber}, checkpoint is ${checkpointNumber}. Message checkpoint is ${msgCheckpoint}. Witness ${!!witness}. Ready ${isReady}.`,
         );