fix(fast-inbox): expose getL1ToL2MessageIndex on the node so wait-for-message-seen works pre-consumption (A-1384)

The flip repointed getL1ToL2MessageCheckpoint to answer from block records (it
now returns undefined until a block consumes the message), silently breaking
waitForL1ToL2MessageSeen's contract that it only confirms the archiver ingested
the message from L1, without requiring the L2 chain to advance. Every caller uses
the two-phase wait-seen-then-advance pattern with tight windows, so the l1-reorgs
messages e2e (and message harnesses) time out waiting for a checkpoint that needs
inbox lag plus a consuming block. Add getL1ToL2MessageIndex to the AztecNode
interface/schema/server (delegating to the existing message source method) and
repoint waitForL1ToL2MessageSeen to it, restoring the pre-consumption lookup over
a remote-capable node.

Author: spalladino

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

@@ -678,6 +678,10 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
     return this.worldStateQueries.getL1ToL2MessageCheckpoint(l1ToL2Message);
   }
 
+  public getL1ToL2MessageIndex(l1ToL2Message: Fr): Promise<bigint | undefined> {
+    return this.worldStateQueries.getL1ToL2MessageIndex(l1ToL2Message);
+  }
+
   /**
    * Returns all the L2 to L1 messages in an epoch.
    *

yarn-project/aztec-node/src/modules/node_world_state_queries.ts

@@ -183,6 +183,10 @@ export class NodeWorldStateQueries {
     return [witness.index, witness.path];
   }
 
+  public getL1ToL2MessageIndex(l1ToL2Message: Fr): Promise<bigint | undefined> {
+    return this.l1ToL2MessageSource.getL1ToL2MessageIndex(l1ToL2Message);
+  }
+
   public async getL1ToL2MessageCheckpoint(l1ToL2Message: Fr): Promise<CheckpointNumber | undefined> {
     const messageIndex = await this.l1ToL2MessageSource.getL1ToL2MessageIndex(l1ToL2Message);
     if (messageIndex === undefined) {

yarn-project/end-to-end/src/shared/wait_for_l1_to_l2_message.ts

@@ -10,12 +10,12 @@ import { retryUntil } from '@aztec/foundation/retry';
  * blocks afterwards to make the message consumable.
  */
 export function waitForL1ToL2MessageSeen(
-  node: Pick<AztecNode, 'getL1ToL2MessageCheckpoint'>,
+  node: Pick<AztecNode, 'getL1ToL2MessageIndex'>,
   l1ToL2MessageHash: Fr,
   opts: { timeoutSeconds: number },
 ) {
   return retryUntil(
-    async () => (await node.getL1ToL2MessageCheckpoint(l1ToL2MessageHash)) !== undefined,
+    async () => (await node.getL1ToL2MessageIndex(l1ToL2MessageHash)) !== undefined,
     `L1 to L2 message ${l1ToL2MessageHash.toString()} seen`,
     opts.timeoutSeconds,
     0.25,

yarn-project/stdlib/src/interfaces/aztec-node.test.ts

@@ -159,6 +159,11 @@ describe('AztecNodeApiSchema', () => {
     expect(response).toEqual(5);
   });
 
+  it('getL1ToL2MessageIndex', async () => {
+    const response = await context.client.getL1ToL2MessageIndex(Fr.random());
+    expect(response).toEqual(5n);
+  });
+
   it('getL2ToL1Messages', async () => {
     const response = await context.client.getL2ToL1Messages(EpochNumber(1));
     expect(response.length).toBe(3);
@@ -714,6 +719,10 @@ class MockAztecNode implements AztecNode {
     expect(l1ToL2Message).toBeInstanceOf(Fr);
     return Promise.resolve(CheckpointNumber(5));
   }
+  getL1ToL2MessageIndex(l1ToL2Message: Fr): Promise<bigint | undefined> {
+    expect(l1ToL2Message).toBeInstanceOf(Fr);
+    return Promise.resolve(5n);
+  }
   getL2ToL1Messages(_epoch: EpochNumber): Promise<Fr[][][][]> {
     return Promise.resolve(
       Array.from({ length: 3 }, (_, i) =>

yarn-project/stdlib/src/interfaces/aztec-node.ts

@@ -203,6 +203,13 @@ export interface AztecNode {
   /** Returns the L2 checkpoint number in which this L1 to L2 message becomes available, or undefined if not found. */
   getL1ToL2MessageCheckpoint(l1ToL2Message: Fr): Promise<CheckpointNumber | undefined>;
 
+  /**
+   * Returns the compact leaf index assigned to this L1 to L2 message as soon as the node has ingested it from L1,
+   * before any L2 block consumes it. Returns undefined if the node has not yet seen the message. Unlike
+   * {@link getL1ToL2MessageCheckpoint}, this does not require the L2 chain to have advanced past the message.
+   */
+  getL1ToL2MessageIndex(l1ToL2Message: Fr): Promise<bigint | undefined>;
+
   /**
    * Returns all the L2 to L1 messages in an epoch.
    *
@@ -611,6 +618,8 @@ export const AztecNodeApiSchema: ApiSchemaFor<AztecNode> = {
 
   getL1ToL2MessageCheckpoint: z.function({ input: z.tuple([schemas.Fr]), output: CheckpointNumberSchema.optional() }),
 
+  getL1ToL2MessageIndex: z.function({ input: z.tuple([schemas.Fr]), output: schemas.BigInt.optional() }),
+
   getL2ToL1Messages: z.function({
     input: z.tuple([EpochNumberSchema]),
     output: z.array(z.array(z.array(z.array(schemas.Fr)))),