fix: sorting artifact props and members in metadata (#9772)

After discussions with @spalladino, it was decided to use the schema
parser to enforce object property ordering, and a schema transform to
enforce array ordering. This PR is enabled to work by the schema work
done by @spalladino, and simply sorts our known arrays that are normally
outputted in a non-deterministic fashion by the noir compiler.

---------

Co-authored-by: Nicolás Venturo <[email protected]>

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

@@ -1,6 +1,10 @@
 import { type ContractArtifact } from '@aztec/foundation/abi';
+import { loadContractArtifact } from '@aztec/types/abi';
+import type { NoirCompiledContract } from '@aztec/types/noir';
 
-import { getTestContractArtifact } from '../tests/fixtures.js';
+import { readFileSync } from 'fs';
+
+import { getPathToFixture, getTestContractArtifact } from '../tests/fixtures.js';
 import { computeArtifactHash } from './artifact_hash.js';
 
 describe('ArtifactHash', () => {
@@ -17,7 +21,7 @@ describe('ArtifactHash', () => {
       notes: {},
     };
     expect(computeArtifactHash(emptyArtifact).toString()).toMatchInlineSnapshot(
-      `"0x0c6fd9b48570721c5d36f978d084d77cacbfd2814f1344985f40e62bea6e61be"`,
+      `"0x0dea64e7fa0688017f77bcb7075485485afb4a5f1f8508483398869439f82fdf"`,
     );
   });
 
@@ -26,8 +30,20 @@ describe('ArtifactHash', () => {
 
     for (let i = 0; i < 1000; i++) {
       expect(computeArtifactHash(testArtifact).toString()).toMatchInlineSnapshot(
-        `"0x11ba97d2d4de6335cc86d271d3c4a6237840cf630eaa442cf75d1666ff475f61"`,
+        `"0x237feccc8e34a39c0e5133c8653fc278b39275bfa3f7459e4aba07d53b752c19"`,
       );
     }
   });
+
+  it('calculates the test contract artifact hash', () => {
+    const path = getPathToFixture('Test.test.json');
+    const content = JSON.parse(readFileSync(path).toString()) as NoirCompiledContract;
+    content.outputs.structs.functions.reverse();
+
+    const testArtifact = loadContractArtifact(content);
+
+    expect(computeArtifactHash(testArtifact).toString()).toMatchInlineSnapshot(
+      `"0x237feccc8e34a39c0e5133c8653fc278b39275bfa3f7459e4aba07d53b752c19"`,
+    );
+  });
 });

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

@@ -59,11 +59,7 @@ export function computeArtifactHashPreimage(artifact: ContractArtifact) {
 }
 
 export function computeArtifactMetadataHash(artifact: ContractArtifact) {
-  // TODO: #6021 We need to make sure the artifact is deterministic from any specific compiler run. This relates to selectors not being sorted and being
-  // apparently random in the order they appear after compiled w/ nargo. We can try to sort this upon loading an artifact.
-  // TODO: #6021: Should we use the sorted event selectors instead? They'd need to be unique for that.
-  // Response - The output selectors need to be sorted, because if not noir makes no guarantees on the order of outputs for some reason
-  return sha256Fr(Buffer.from(JSON.stringify({ name: artifact.name }), 'utf-8'));
+  return sha256Fr(Buffer.from(JSON.stringify({ name: artifact.name, outputs: artifact.outputs }), 'utf-8'));
 }
 
 export function computeArtifactFunctionTreeRoot(artifact: ContractArtifact, fnType: FunctionType) {

yarn-project/circuits.js/src/tests/fixtures.ts

@@ -48,6 +48,6 @@ export function getSampleUnconstrainedFunctionBroadcastedEventPayload(): Buffer
   return Buffer.from(readFileSync(path).toString(), 'hex');
 }
 
-function getPathToFixture(name: string) {
+export function getPathToFixture(name: string) {
   return resolve(dirname(fileURLToPath(import.meta.url)), `../../fixtures/${name}`);
 }

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

@@ -358,7 +358,18 @@ export const ContractArtifactSchema: ZodFor<ContractArtifact> = z.object({
   aztecNrVersion: z.string().optional(),
   functions: z.array(FunctionArtifactSchema),
   outputs: z.object({
-    structs: z.record(z.array(AbiTypeSchema)),
+    structs: z.record(z.array(AbiTypeSchema)).transform(structs => {
+      for (const [key, value] of Object.entries(structs)) {
+        // We are manually ordering events and functions in the abi by path.
+        // The path ordering is arbitrary, and only needed to ensure deterministic order.
+        // These are the only arrays in the artifact with arbitrary order, and hence the only ones
+        // we need to sort.
+        if (key === 'events' || key === 'functions') {
+          structs[key] = (value as StructType[]).sort((a, b) => (a.path > b.path ? -1 : 1));
+        }
+      }
+      return structs;
+    }),
     globals: z.record(z.array(AbiValueSchema)),
   }),
   storageLayout: z.record(z.object({ slot: schemas.Fr })),