Issue 62 PR 05: Event-hash integrity reconciliation

Author: snissn

SPEC.md

@@ -995,7 +995,7 @@ Token Host MUST emit, per collection:
 - `RecordDeleted(collectionId, recordId, actor, timestamp, isHardDelete)`
 - `RecordTransferred(collectionId, recordId, fromOwner, toOwner, actor, timestamp)` (only for collections with transfers enabled)
 
-`dataHash` and `changedFieldsHash` SHOULD be keccak256 of ABI-encoded values to allow indexers to detect mismatches without storing full payloads in events. Token Host MAY additionally emit field-level events for frequently queried fields.
+`dataHash` and `changedFieldsHash` SHOULD be keccak256 of ABI-encoded values to allow indexers to detect mismatches without storing full payloads in events. In v1, `changedFieldsHash` MAY carry the post-update record hash rather than a minimal delta-only hash, so long as the generator applies the rule deterministically and documents it. Token Host MAY additionally emit field-level events for frequently queried fields.
 
 #### 7.9.1 Event indexing for narrow subscriptions (normative)
 
@@ -1103,6 +1103,8 @@ This design ensures:
 - identical records across environments produce identical hashes,
 - indexers can recompute the hash from decoded record values to detect RPC inconsistencies.
 
+For update events, the generator MAY place this post-update `recordHash` into the `changedFieldsHash` event slot in v1. That preserves a stable event surface while still giving indexers an integrity primitive tied to the resulting stored record state.
+
 ### 7.15 Error model
 
 Generated contracts MUST use explicit, distinguishable reverts. For gas efficiency, Token Host SHOULD prefer Solidity custom errors over string revert reasons.

packages/generator/src/solidity/generateAppSolidity.ts

@@ -79,6 +79,13 @@ function queryIndexKeyExpr(fieldType: FieldType, expr: string): string {
     : `keccak256(abi.encode(${expr}))`;
 }
 
+function chunkArray<T>(items: T[], size: number): T[][] {
+  if (size <= 0) return [items.slice()];
+  const out: T[][] = [];
+  for (let i = 0; i < items.length; i += size) out.push(items.slice(i, i + size));
+  return out;
+}
+
 class W {
   private lines: string[] = [];
   private indent = 0;
@@ -130,10 +137,6 @@ function bytes32FromSha256(schemaHash: string): string {
   return `0x${m[1]}`;
 }
 
-function recordHashFnName(collectionName: string): string {
-  return `_hashRecord${collectionName}`;
-}
-
 export function generateAppSolidity(schema: ThsSchema, options: GenerateAppSolidityOptions = {}): { path: string; contents: string } {
   const w = new W();
 
@@ -257,7 +260,7 @@ export function generateAppSolidity(schema: ThsSchema, options: GenerateAppSolid
         w.line('(bool ok, bytes memory res) = address(this).delegatecall(calls[i]);');
         w.block('if (!ok)', () => {
           // bubble up revert data (best-effort)
-          w.block('assembly', () => {
+          w.block('assembly ("memory-safe")', () => {
             w.line('revert(add(res, 32), mload(res))');
           });
         });
@@ -359,14 +362,6 @@ export function generateAppSolidity(schema: ThsSchema, options: GenerateAppSolid
       });
       w.line();
 
-      // Record hashing helper (used for event integrity without stack-too-deep risk).
-      // Note: this uses ABI encoding of the full record tuple; callers can recompute
-      // from decoded record values.
-      w.block(`function ${recordHashFnName(C)}(${record} memory r) internal pure returns (bytes32)`, () => {
-        w.line(`return keccak256(abi.encode(COLLECTION_ID_${C}, r));`);
-      });
-      w.line();
-
       w.block(`function _init${record}(${record} storage r, uint256 id) internal`, () => {
         w.line('r.id = id;');
         w.line('r.createdAt = block.timestamp;');
@@ -380,17 +375,45 @@ export function generateAppSolidity(schema: ThsSchema, options: GenerateAppSolid
       });
       w.line();
 
+      const createFieldChunks = chunkArray(c.fields, 4);
+      for (let i = 0; i < createFieldChunks.length; i++) {
+        const chunk = createFieldChunks[i]!;
+        w.block(`function _applyCreate${C}Fields_${i}(${record} storage r, ${createInputStruct} calldata input) internal`, () => {
+          for (const f of chunk) {
+            w.line(`r.${f.name} = input.${f.name};`);
+          }
+        });
+        w.line();
+      }
+
       w.block(`function _applyCreate${C}Fields(${record} storage r, ${createInputStruct} calldata input) internal`, () => {
-        for (const f of c.fields) {
-          w.line(`r.${f.name} = input.${f.name};`);
+        for (let i = 0; i < createFieldChunks.length; i++) {
+          w.line(`_applyCreate${C}Fields_${i}(r, input);`);
         }
       });
       w.line();
 
+      const recordHashParts = [
+        'COLLECTION_ID_' + C,
+        'r.id',
+        'r.createdAt',
+        'r.createdBy',
+        'r.owner',
+        'r.updatedAt',
+        'r.updatedBy',
+        'r.isDeleted',
+        'r.deletedAt',
+        'r.version',
+        ...c.fields.map((f) => `r.${f.name}`)
+      ];
+      w.block(`function _recordHash${C}(${record} storage r) internal view returns (bytes32)`, () => {
+        w.line(`return keccak256(abi.encode(${recordHashParts.join(', ')}));`);
+      });
+      w.line();
+
       w.block(`function _emitCreated${C}(uint256 id) internal`, () => {
-        w.line(`${record} memory m = ${cVar}Records[id];`);
-        w.line(`bytes32 dataHash = ${recordHashFnName(C)}(m);`);
-        w.line(`emit RecordCreated(COLLECTION_ID_${C}, id, _msgSender(), block.timestamp, dataHash);`);
+        w.line(`${record} storage r = ${cVar}Records[id];`);
+        w.line(`emit RecordCreated(COLLECTION_ID_${C}, id, _msgSender(), block.timestamp, _recordHash${C}(r));`);
       });
       w.line();
 
@@ -805,9 +828,7 @@ export function generateAppSolidity(schema: ThsSchema, options: GenerateAppSolid
           w.line('r.updatedAt = block.timestamp;');
           w.line('r.updatedBy = _msgSender();');
           w.line('r.version += 1;');
-          w.line(`${record} memory m = r;`);
-          w.line(`bytes32 changedFieldsHash = ${recordHashFnName(C)}(m);`);
-          w.line(`emit RecordUpdated(COLLECTION_ID_${C}, id, _msgSender(), block.timestamp, changedFieldsHash);`);
+          w.line(`emit RecordUpdated(COLLECTION_ID_${C}, id, _msgSender(), block.timestamp, _recordHash${C}(r));`);
         });
         w.line();
       }

test/testCliBenchmarkRegistryBuild.js

@@ -26,6 +26,7 @@ describe('th build (benchmark registry schema)', function () {
     const appSol = fs.readFileSync(path.join(outDir, 'contracts', 'App.sol'), 'utf-8');
     expect(appSol).to.include('struct CreateBenchmarkRunInput');
     expect(appSol).to.include('function createBenchmarkRun(CreateBenchmarkRunInput calldata input)');
+    expect(appSol).to.include('function _recordHashBenchmarkRun');
 
     const compiled = JSON.parse(fs.readFileSync(path.join(outDir, 'compiled', 'App.json'), 'utf-8'));
     expect(String(compiled.compilerProfile || '')).to.match(/auto|large-app/);

test/testCrudGenerator.js

@@ -52,9 +52,10 @@ describe('Spec-aligned CRUD generator', function () {
     expect(appSol.contents).to.include('event RecordCreated');
     expect(appSol.contents).to.include('function createCandidate');
     expect(appSol.contents).to.include('function createJobPosting');
+    expect(appSol.contents).to.include('function _recordHashCandidate');
+    expect(appSol.contents).to.include('function _recordHashJobPosting');
 
     const { errors } = compileSolidity(appSol.path, appSol.contents, 'App');
     expect(errors.map((e) => e.formattedMessage || e.message).join('\n')).to.equal('');
   });
 });
-