fix: EventMetadata class implementation for serialisation (#9574)

This is to fix `getEvents` PXE method over JSON RPC
- Create `EventMetadata` class 
- Remove `decodeEvent` from noir typescript contract generation

cspell.json

@@ -283,6 +283,7 @@
     "Validium",
     "vals",
     "viem",
+    "vpks",
     "Vyper",
     "wasms",
     "webassembly",

yarn-project/aztec.js/src/index.ts

@@ -116,6 +116,7 @@ export {
   EncryptedNoteL2BlockL2Logs,
   EpochProofQuote,
   EpochProofQuotePayload,
+  EventMetadata,
   EventType,
   ExtendedNote,
   FunctionCall,

yarn-project/aztec.js/src/rpc_clients/pxe_client.ts

@@ -5,6 +5,7 @@ import {
   EncryptedL2Log,
   EncryptedL2NoteLog,
   EncryptedNoteL2BlockL2Logs,
+  EventMetadata,
   ExtendedNote,
   ExtendedUnencryptedL2Log,
   L2Block,
@@ -36,7 +37,7 @@ import {
   PrivateCircuitPublicInputs,
   PublicKeys,
 } from '@aztec/circuits.js';
-import { NoteSelector } from '@aztec/foundation/abi';
+import { EventSelector, NoteSelector } from '@aztec/foundation/abi';
 import { Buffer32 } from '@aztec/foundation/buffer';
 import { createJsonRpcClient, makeFetch } from '@aztec/foundation/json-rpc/client';
 
@@ -55,6 +56,7 @@ export const createPXEClient = (url: string, fetch = makeFetch([1, 2, 3], false)
       CompleteAddress,
       FunctionSelector,
       EthAddress,
+      EventSelector,
       ExtendedNote,
       UniqueNote,
       ExtendedUnencryptedL2Log,
@@ -75,6 +77,7 @@ export const createPXEClient = (url: string, fetch = makeFetch([1, 2, 3], false)
       EncryptedNoteL2BlockL2Logs,
       EncryptedL2NoteLog,
       EncryptedL2Log,
+      EventMetadata,
       UnencryptedL2Log,
       NoteSelector,
       NullifierMembershipWitness,

yarn-project/aztec.js/src/wallet/base_wallet.ts

@@ -1,6 +1,5 @@
 import {
   type AuthWitness,
-  type EventMetadata,
   type EventType,
   type ExtendedNote,
   type GetUnencryptedLogsResponse,
@@ -34,7 +33,7 @@ import {
   type PartialAddress,
   type Point,
 } from '@aztec/circuits.js';
-import { type ContractArtifact } from '@aztec/foundation/abi';
+import type { AbiType, ContractArtifact, EventSelector } from '@aztec/foundation/abi';
 
 import { type Wallet } from '../account/wallet.js';
 import { type ExecutionRequestInit } from '../entrypoint/entrypoint.js';
@@ -199,15 +198,22 @@ export abstract class BaseWallet implements Wallet {
   }
   getEvents<T>(
     type: EventType,
-    eventMetadata: EventMetadata<T>,
+    event: {
+      /** The event selector */
+      eventSelector: EventSelector;
+      /** The event's abi type */
+      abiType: AbiType;
+      /** The field names */
+      fieldNames: string[];
+    },
     from: number,
     limit: number,
     vpks: Point[] = [
       this.getCompleteAddress().publicKeys.masterIncomingViewingPublicKey,
       this.getCompleteAddress().publicKeys.masterOutgoingViewingPublicKey,
     ],
-  ) {
-    return this.pxe.getEvents(type, eventMetadata, from, limit, vpks);
+  ): Promise<T[]> {
+    return this.pxe.getEvents(type, event, from, limit, vpks);
   }
   public getL1ToL2MembershipWitness(
     contractAddress: AztecAddress,

yarn-project/builder/src/contract-interface-gen/typescript.ts

@@ -257,12 +257,12 @@ function generateEvents(events: any[] | undefined) {
     `;
 
     const fieldNames = event.fields.map((field: any) => `"${field.name}"`);
-    const eventType = `${eventName}: {decode: (payload: L1EventPayload | UnencryptedL2Log | undefined) => ${eventName} | undefined, eventSelector: EventSelector, fieldNames: string[] }`;
+    const eventType = `${eventName}: {abiType: AbiType, eventSelector: EventSelector, fieldNames: string[] }`;
     // Reusing the decodeFunctionSignature
     const eventSignature = decodeFunctionSignature(eventName, event.fields);
     const eventSelector = `EventSelector.fromSignature('${eventSignature}')`;
     const eventImpl = `${eventName}: {
-        decode: this.decodeEvent(${eventSelector}, ${JSON.stringify(event, null, 4)}),
+        abiType: ${JSON.stringify(event, null, 4)},
         eventSelector: ${eventSelector},
         fieldNames: [${fieldNames}],
       }`;
@@ -277,32 +277,6 @@ function generateEvents(events: any[] | undefined) {
   return {
     eventDefs: eventsMetadata.map(({ eventDef }) => eventDef).join('\n'),
     events: `
-    // Partial application is chosen is to avoid the duplication of so much codegen.
-    private static decodeEvent<T>(
-      eventSelector: EventSelector,
-      eventType: AbiType,
-    ): (payload: L1EventPayload | UnencryptedL2Log | undefined) => T | undefined {
-      return (payload: L1EventPayload | UnencryptedL2Log | undefined): T | undefined => {
-        if (payload === undefined) {
-          return undefined;
-        }
-
-        if (payload instanceof L1EventPayload) {
-          if (!eventSelector.equals(payload.eventTypeId)) {
-            return undefined;
-          }
-          return decodeFromAbi([eventType], payload.event.items) as T;
-        } else {
-          let items = [];
-          for (let i = 0; i < payload.data.length; i += 32) {
-            items.push(new Fr(payload.data.subarray(i, i + 32)));
-          }
-
-          return decodeFromAbi([eventType], items) as T;
-        }
-      };
-    }
-
     public static get events(): { ${eventsMetadata.map(({ eventType }) => eventType).join(', ')} } {
     return {
       ${eventsMetadata.map(({ eventImpl }) => eventImpl).join(',\n')}

yarn-project/circuit-types/src/interfaces/pxe.ts

@@ -10,16 +10,11 @@ import {
   type Point,
   type ProtocolContractAddresses,
 } from '@aztec/circuits.js';
-import { type ContractArtifact, type EventSelector } from '@aztec/foundation/abi';
+import type { AbiType, ContractArtifact, EventSelector } from '@aztec/foundation/abi';
 
 import { type AuthWitness } from '../auth_witness.js';
 import { type L2Block } from '../l2_block.js';
-import {
-  type GetUnencryptedLogsResponse,
-  type L1EventPayload,
-  type LogFilter,
-  type UnencryptedL2Log,
-} from '../logs/index.js';
+import { type GetUnencryptedLogsResponse, type LogFilter } from '../logs/index.js';
 import { type IncomingNotesFilter } from '../notes/incoming_notes_filter.js';
 import { type ExtendedNote, type OutgoingNotesFilter, type UniqueNote } from '../notes/index.js';
 import { type PrivateExecutionResult } from '../private_execution_result.js';
@@ -409,31 +404,22 @@ export interface PXE {
   /**
    * Returns the events of a specified type given search parameters.
    * @param type - The type of the event to search for—Encrypted, or Unencrypted.
-   * @param eventMetadata - Identifier of the event. This should be the class generated from the contract. e.g. Contract.events.Event
+   * @param eventMetadata - Metadata of the event. This should be the class generated from the contract. e.g. Contract.events.Event
    * @param from - The block number to search from.
    * @param limit - The amount of blocks to search.
    * @param vpks - (Used for encrypted logs only) The viewing (incoming and outgoing) public keys that correspond to the viewing secret keys that can decrypt the log.
    * @returns - The deserialized events.
    */
   getEvents<T>(
     type: EventType,
-    eventMetadata: EventMetadata<T>,
+    eventMetadata: { eventSelector: EventSelector; abiType: AbiType; fieldNames: string[] },
     from: number,
     limit: number,
     vpks: Point[],
   ): Promise<T[]>;
 }
 // docs:end:pxe-interface
 
-/**
- * The shape of the event generated on the Contract.
- */
-export interface EventMetadata<T> {
-  decode(payload: L1EventPayload | UnencryptedL2Log): T | undefined;
-  eventSelector: EventSelector;
-  fieldNames: string[];
-}
-
 /**
  * This is used in getting events via the filter
  */

yarn-project/circuit-types/src/logs/event_metadata.ts

@@ -0,0 +1,77 @@
+import { EventType, L1EventPayload, type UnencryptedL2Log } from '@aztec/circuit-types';
+import { type AbiType } from '@aztec/foundation/abi';
+import { EventSelector, decodeFromAbi } from '@aztec/foundation/abi';
+import { Fr } from '@aztec/foundation/fields';
+
+/**
+ * Represents metadata for an event decoder, including all information needed to reconstruct it.
+ */
+export class EventMetadata<T> {
+  public readonly decode: (payload: L1EventPayload | UnencryptedL2Log) => T | undefined;
+
+  public readonly eventSelector: EventSelector;
+  public readonly abiType: AbiType;
+  public readonly fieldNames: string[];
+
+  constructor(
+    public readonly eventType: EventType,
+    event: { eventSelector: EventSelector; abiType: AbiType; fieldNames: string[] },
+  ) {
+    this.eventSelector = event.eventSelector;
+    this.abiType = event.abiType;
+    this.fieldNames = event.fieldNames;
+    this.decode = EventMetadata.decodeEvent<T>(event.eventSelector, event.abiType);
+  }
+
+  public static decodeEvent<T>(
+    eventSelector: EventSelector,
+    abiType: AbiType,
+  ): (payload: L1EventPayload | UnencryptedL2Log | undefined) => T | undefined {
+    return (payload: L1EventPayload | UnencryptedL2Log | undefined): T | undefined => {
+      if (payload === undefined) {
+        return undefined;
+      }
+
+      if (payload instanceof L1EventPayload) {
+        if (!eventSelector.equals(payload.eventTypeId)) {
+          return undefined;
+        }
+        return decodeFromAbi([abiType], payload.event.items) as T;
+      } else {
+        const items = [];
+        for (let i = 0; i < payload.data.length; i += 32) {
+          items.push(new Fr(payload.data.subarray(i, i + 32)));
+        }
+
+        return decodeFromAbi([abiType], items) as T;
+      }
+    };
+  }
+
+  /**
+   * Serializes the metadata to a JSON-friendly format
+   */
+  public toJSON() {
+    return {
+      type: 'event_metadata',
+      eventSelector: this.eventSelector.toString(),
+      eventType: this.eventType,
+      fieldNames: this.fieldNames,
+    };
+  }
+
+  /**
+   * Creates an EventMetadata instance from a JSON representation
+   */
+  public static fromJSON(json: any): EventMetadata<any> {
+    if (json?.type !== 'event_metadata') {
+      throw new Error('Invalid event metadata format');
+    }
+
+    return new EventMetadata(EventType.Encrypted, {
+      eventSelector: EventSelector.fromString(json.eventSelector),
+      abiType: json.abiType,
+      fieldNames: json.fieldNames,
+    });
+  }
+}

yarn-project/circuit-types/src/logs/index.ts

@@ -1,5 +1,6 @@
 export * from './encrypted_l2_note_log.js';
 export * from './encrypted_l2_log.js';
+export * from './event_metadata.js';
 export * from './get_unencrypted_logs_response.js';
 export * from './function_l2_logs.js';
 export * from './l2_block_l2_logs.js';

yarn-project/end-to-end/src/e2e_event_logs.test.ts

@@ -1,6 +1,7 @@
 import {
   type AccountWalletWithSecretKey,
   type AztecNode,
+  EventMetadata,
   EventType,
   Fr,
   L1EventPayload,
@@ -61,14 +62,18 @@ describe('Logs', () => {
       expect(decryptedEvent0.eventTypeId).toStrictEqual(EventSelector.fromSignature('ExampleEvent0(Field,Field)'));
 
       // We decode our event into the event type
-      const event0 = TestLogContract.events.ExampleEvent0.decode(decryptedEvent0);
+      const event0Metadata = new EventMetadata<ExampleEvent0>(
+        EventType.Encrypted,
+        TestLogContract.events.ExampleEvent0,
+      );
+      const event0 = event0Metadata.decode(decryptedEvent0);
 
       // We check that the event was decoded correctly
       expect(event0?.value0).toStrictEqual(preimage[0].toBigInt());
       expect(event0?.value1).toStrictEqual(preimage[1].toBigInt());
 
       // We check that an event that does not match, is not decoded correctly due to an event type id mismatch
-      const badEvent0 = TestLogContract.events.ExampleEvent1.decode(decryptedEvent0);
+      const badEvent0 = event0Metadata.decode(decryptedEvent0);
       expect(badEvent0).toBe(undefined);
 
       const decryptedEvent1 = L1EventPayload.decryptAsIncoming(encryptedLogs[2], wallets[0].getEncryptionSecret())!;
@@ -78,15 +83,20 @@ describe('Logs', () => {
       expect(decryptedEvent1.eventTypeId).toStrictEqual(EventSelector.fromSignature('ExampleEvent1((Field),u8)'));
 
       // We check our second event, which is a different type
-      const event1 = TestLogContract.events.ExampleEvent1.decode(decryptedEvent1);
+      const event1Metadata = new EventMetadata<ExampleEvent1>(
+        EventType.Encrypted,
+        TestLogContract.events.ExampleEvent1,
+      );
+
+      const event1 = event1Metadata.decode(decryptedEvent1);
 
       // We expect the fields to have been populated correctly
       expect(event1?.value2).toStrictEqual(preimage[2]);
       // We get the last byte here because value3 is of type u8
       expect(event1?.value3).toStrictEqual(BigInt(preimage[3].toBuffer().subarray(31).readUint8()));
 
       // Again, trying to decode another event with mismatching data does not yield anything
-      const badEvent1 = TestLogContract.events.ExampleEvent0.decode(decryptedEvent1);
+      const badEvent1 = event1Metadata.decode(decryptedEvent1);
       expect(badEvent1).toBe(undefined);
     });
 
@@ -113,14 +123,15 @@ describe('Logs', () => {
         .wait();
 
       // We get all the events we can decrypt with either our incoming or outgoing viewing keys
-      const collectedEvent0s = await wallets[0].getEvents(
+
+      const collectedEvent0s = await wallets[0].getEvents<ExampleEvent0>(
         EventType.Encrypted,
         TestLogContract.events.ExampleEvent0,
         firstTx.blockNumber!,
         lastTx.blockNumber! - firstTx.blockNumber! + 1,
       );
 
-      const collectedEvent0sWithIncoming = await wallets[0].getEvents(
+      const collectedEvent0sWithIncoming = await wallets[0].getEvents<ExampleEvent0>(
         EventType.Encrypted,
         TestLogContract.events.ExampleEvent0,
         firstTx.blockNumber!,
@@ -129,15 +140,15 @@ describe('Logs', () => {
         [wallets[0].getCompleteAddress().publicKeys.masterIncomingViewingPublicKey],
       );
 
-      const collectedEvent0sWithOutgoing = await wallets[0].getEvents(
+      const collectedEvent0sWithOutgoing = await wallets[0].getEvents<ExampleEvent0>(
         EventType.Encrypted,
         TestLogContract.events.ExampleEvent0,
         firstTx.blockNumber!,
         lastTx.blockNumber! - firstTx.blockNumber! + 1,
         [wallets[0].getCompleteAddress().publicKeys.masterOutgoingViewingPublicKey],
       );
 
-      const collectedEvent1s = await wallets[0].getEvents(
+      const collectedEvent1s = await wallets[0].getEvents<ExampleEvent1>(
         EventType.Encrypted,
         TestLogContract.events.ExampleEvent1,
         firstTx.blockNumber!,
@@ -150,7 +161,7 @@ describe('Logs', () => {
       expect(collectedEvent0s.length).toBe(10);
       expect(collectedEvent1s.length).toBe(5);
 
-      const emptyEvent1s = await wallets[0].getEvents(
+      const emptyEvent1s = await wallets[0].getEvents<ExampleEvent1>(
         EventType.Encrypted,
         TestLogContract.events.ExampleEvent1,
         firstTx.blockNumber!,
@@ -199,14 +210,14 @@ describe('Logs', () => {
       );
       const lastTx = await testLogContract.methods.emit_unencrypted_events(preimage[++i]).send().wait();
 
-      const collectedEvent0s = await wallets[0].getEvents(
+      const collectedEvent0s = await wallets[0].getEvents<ExampleEvent0>(
         EventType.Unencrypted,
         TestLogContract.events.ExampleEvent0,
         firstTx.blockNumber!,
         lastTx.blockNumber! - firstTx.blockNumber! + 1,
       );
 
-      const collectedEvent1s = await wallets[0].getEvents(
+      const collectedEvent1s = await wallets[0].getEvents<ExampleEvent1>(
         EventType.Unencrypted,
         TestLogContract.events.ExampleEvent1,
         firstTx.blockNumber!,