fix: add zod parsing for generated contract artifacts (#9905)

This PR enables us to enforce deterministic contract artifact JSON
stringifying. This is because now when we generate our contract
artifact, we pass it through our zod parser, which enforces ordering in
the object, and enforces correct ordering of props in objects. This is
related to #6021, which we need for deterministic artifact hashes.

yarn-project/circuits.js/src/contract/artifact_hash.test.ts

@@ -1,5 +1,6 @@
 import { type ContractArtifact } from '@aztec/foundation/abi';
 
+import { getTestContractArtifact } from '../tests/fixtures.js';
 import { computeArtifactHash } from './artifact_hash.js';
 
 describe('ArtifactHash', () => {
@@ -19,4 +20,14 @@ describe('ArtifactHash', () => {
       `"0x0c6fd9b48570721c5d36f978d084d77cacbfd2814f1344985f40e62bea6e61be"`,
     );
   });
+
+  it('calculates the test contract artifact hash multiple times to ensure deterministic hashing', () => {
+    const testArtifact = getTestContractArtifact();
+
+    for (let i = 0; i < 1000; i++) {
+      expect(computeArtifactHash(testArtifact).toString()).toMatchInlineSnapshot(
+        `"0x11ba97d2d4de6335cc86d271d3c4a6237840cf630eaa442cf75d1666ff475f61"`,
+      );
+    }
+  });
 });

yarn-project/foundation/src/abi/note_selector.ts

@@ -27,7 +27,7 @@ export class NoteSelector extends Selector {
   }
 
   static fromString(buf: string) {
-    const withoutPrefix = buf.replace(/^0x/i, '');
+    const withoutPrefix = buf.replace(/^0x/i, '').slice(-8);
     const buffer = Buffer.from(withoutPrefix, 'hex');
     return NoteSelector.fromBuffer(buffer);
   }

yarn-project/types/src/abi/contract_artifact.ts

@@ -4,16 +4,15 @@ import {
   type AbiType,
   type BasicValue,
   type ContractArtifact,
+  ContractArtifactSchema,
   type ContractNote,
   type FieldLayout,
   type FunctionArtifact,
   FunctionType,
   type IntegerValue,
-  NoteSelector,
   type StructValue,
   type TypedStructFieldValue,
 } from '@aztec/foundation/abi';
-import { Fr } from '@aztec/foundation/fields';
 
 import {
   AZTEC_INITIALIZER_ATTRIBUTE,
@@ -53,18 +52,7 @@ export function contractArtifactToBuffer(artifact: ContractArtifact): Buffer {
  * @returns Deserialized artifact.
  */
 export function contractArtifactFromBuffer(buffer: Buffer): ContractArtifact {
-  return JSON.parse(buffer.toString('utf-8'), (key, value) => {
-    if (key === 'bytecode' && typeof value === 'string') {
-      return Buffer.from(value, 'base64');
-    }
-    if (typeof value === 'object' && value !== null && value.type === 'NoteSelector') {
-      return new NoteSelector(Number(value.value));
-    }
-    if (typeof value === 'object' && value !== null && value.type === 'Fr') {
-      return new Fr(BigInt(value.value));
-    }
-    return value;
-  });
+  return ContractArtifactSchema.parse(JSON.parse(buffer.toString('utf-8')));
 }
 
 /**
@@ -133,7 +121,10 @@ type NoirCompiledContractFunction = NoirCompiledContract['functions'][number];
  * @param contract - Parent contract.
  * @returns Function artifact.
  */
-function generateFunctionArtifact(fn: NoirCompiledContractFunction, contract: NoirCompiledContract): FunctionArtifact {
+function generateFunctionArtifact(
+  fn: NoirCompiledContractFunction,
+  contract: NoirCompiledContract,
+): Omit<FunctionArtifact, 'bytecode'> & { bytecode: string } {
   if (fn.custom_attributes === undefined) {
     throw new Error(
       `No custom attributes found for contract function ${fn.name}. Try rebuilding the contract with the latest nargo version.`,
@@ -178,7 +169,7 @@ function generateFunctionArtifact(fn: NoirCompiledContractFunction, contract: No
     isInitializer: fn.custom_attributes.includes(AZTEC_INITIALIZER_ATTRIBUTE),
     parameters,
     returnTypes,
-    bytecode: Buffer.from(fn.bytecode, 'base64'),
+    bytecode: fn.bytecode,
     debugSymbols: fn.debug_symbols,
     errorTypes: fn.abi.error_types,
     ...(fn.assert_messages ? { assertMessages: fn.assert_messages } : undefined),
@@ -238,11 +229,11 @@ function getStorageLayout(input: NoirCompiledContract) {
     return {};
   }
 
-  return storageFields.reduce((acc: Record<string, FieldLayout>, field) => {
+  return storageFields.reduce((acc: Record<string, Omit<FieldLayout, 'slot'> & { slot: string }>, field) => {
     const name = field.name;
     const slot = field.value.fields[0].value as IntegerValue;
     acc[name] = {
-      slot: Fr.fromString(slot.value),
+      slot: slot.value,
     };
     return acc;
   }, {});
@@ -262,7 +253,7 @@ function getNoteTypes(input: NoirCompiledContract) {
     return {};
   }
 
-  return notes.reduce((acc: Record<string, ContractNote>, note) => {
+  return notes.reduce((acc: Record<string, Omit<ContractNote, 'id'> & { id: string }>, note) => {
     const noteFields = note.fields;
 
     // We find note type id by looking for respective kinds as each of them is unique
@@ -274,7 +265,7 @@ function getNoteTypes(input: NoirCompiledContract) {
       throw new Error(`Could not find note type id, name or fields for note ${note}`);
     }
 
-    const noteTypeId = NoteSelector.fromField(Fr.fromString(rawNoteTypeId.value));
+    const noteTypeId = rawNoteTypeId.value as string;
     const name = rawName.value as string;
 
     // Note type id is encoded as a hex string
@@ -301,15 +292,15 @@ function getNoteTypes(input: NoirCompiledContract) {
  */
 function generateContractArtifact(contract: NoirCompiledContract, aztecNrVersion?: string): ContractArtifact {
   try {
-    return {
+    return ContractArtifactSchema.parse({
       name: contract.name,
       functions: contract.functions.map(f => generateFunctionArtifact(f, contract)),
       outputs: contract.outputs,
       storageLayout: getStorageLayout(contract),
       notes: getNoteTypes(contract),
       fileMap: contract.file_map,
       ...(aztecNrVersion ? { aztecNrVersion } : {}),
-    };
+    });
   } catch (err) {
     throw new Error(`Could not generate contract artifact for ${contract.name}: ${err}`);
   }