Handle type and field name conflicts for eden-watcher subgraph entities (#50)

* Rename Block, Transaction types and add block query in eden-watcher schema

* Handle field name conflicts in eden subgraph entities

* Resolve entity field name conflicts while sending data for auto-diff

packages/graph-node/src/database.ts

@@ -83,7 +83,7 @@ export class Database {
     const entityValuePromises = entityFields.filter(field => {
       const { propertyName } = field;
 
-      // TODO: Will clash if entity has blockHash and blockNumber fields.
+      // Filter out blockHash and blockNumber from entity fields to fill the entityInstance (wasm).
       if (propertyName === 'blockHash' || propertyName === 'blockNumber') {
         return false;
       }
@@ -92,6 +92,11 @@ export class Database {
     }).map(async (field) => {
       const { type, propertyName } = field;
 
+      // Fill _blockNumber as blockNumber and _blockHash as blockHash in the entityInstance (wasm).
+      if (['_blockNumber', '_blockHash'].includes(propertyName)) {
+        return toEntityValue(instanceExports, entityInstance, data, type.toString(), propertyName.slice(1));
+      }
+
       return toEntityValue(instanceExports, entityInstance, data, type.toString(), propertyName);
     }, {});
 
@@ -112,15 +117,21 @@ export class Database {
     const entityValuePromises = entityFields.map(async (field: any) => {
       const { type, propertyName } = field;
 
-      // TODO: Will clash if entity has blockHash and blockNumber fields.
+      // Get blockHash property for db entry from block instance.
       if (propertyName === 'blockHash') {
         return block.blockHash;
       }
 
+      // Get blockNumber property for db entry from block instance.
       if (propertyName === 'blockNumber') {
         return block.blockNumber;
       }
 
+      // Get blockNumber as _blockNumber and blockHash as _blockHash from the entityInstance (wasm).
+      if (['_blockNumber', '_blockHash'].includes(propertyName)) {
+        return fromEntityValue(instanceExports, entityInstance, type.toString(), propertyName.slice(1));
+      }
+
       return fromEntityValue(instanceExports, entityInstance, type.toString(), propertyName);
     }, {});
 

packages/graph-node/src/loader.ts

@@ -18,7 +18,7 @@ import JSONbig from 'json-bigint';
 import { IndexerInterface } from '@vulcanize/util';
 
 import { TypeId } from './types';
-import { Block, fromEthereumValue, toEthereumValue } from './utils';
+import { Block, fromEthereumValue, toEthereumValue, resolveEntityFieldConflicts } from './utils';
 import { Database } from './database';
 
 const NETWORK_URL = 'http://127.0.0.1:8081';
@@ -66,15 +66,15 @@ export const instantiate = async (database: Database, indexer: IndexerInterface,
         const entityInstance = await Entity.wrap(data);
 
         assert(context.event.block);
-        const dbData = await database.fromGraphEntity(exports, context.event.block, entityName, entityInstance);
+        let dbData = await database.fromGraphEntity(exports, context.event.block, entityName, entityInstance);
         await database.saveEntity(entityName, dbData);
 
-        // Remove blockNumber and blockHash from dbData for auto-diff.
-        delete dbData.blockNumber;
-        delete dbData.blockHash;
+        // Resolve any field name conflicts in the dbData for auto-diff.
+        dbData = resolveEntityFieldConflicts(dbData);
 
         // Prepare the diff data.
         const diffData: any = { state: {} };
+
         // JSON stringify and parse data for handling unknown types when encoding.
         // For example, decimal.js values are converted to string in the diff data.
         diffData.state[entityName] = JSONbig.parse(JSONbig.stringify(dbData));

packages/graph-node/src/utils.ts

@@ -396,3 +396,25 @@ export const fromEntityValue = async (instanceExports: any, entityInstance: any,
       throw new Error(`Unsupported type: ${type}`);
   }
 };
+
+export const resolveEntityFieldConflicts = (entity: any): any => {
+  if (entity) {
+    // Remove fields blockHash and blockNumber from the entity.
+    delete entity.blockHash;
+    delete entity.blockNumber;
+
+    // Rename _blockHash -> blockHash.
+    if ('_blockHash' in entity) {
+      entity.blockHash = entity._blockHash;
+      delete entity._blockHash;
+    }
+
+    // Rename _blockNumber -> blockNumber.
+    if ('_blockNumber' in entity) {
+      entity.blockNumber = entity._blockNumber;
+      delete entity._blockNumber;
+    }
+  }
+
+  return entity;
+};

packages/graph-node/src/watcher.ts

@@ -13,7 +13,7 @@ import { ResultObject } from '@vulcanize/assemblyscript/lib/loader';
 import { EthClient } from '@vulcanize/ipld-eth-client';
 import { IndexerInterface } from '@vulcanize/util';
 
-import { createBlock, createEvent, getSubgraphConfig } from './utils';
+import { createBlock, createEvent, getSubgraphConfig, resolveEntityFieldConflicts } from './utils';
 import { Context, instantiate } from './loader';
 import { Database } from './database';
 
@@ -183,7 +183,11 @@ export class GraphWatcher {
     this._indexer = indexer;
   }
 
-  async getEntity<Entity> (entity: new () => Entity, id: string, blockHash: string): Promise<Entity | undefined> {
-    return this._database.getEntity(entity, id, blockHash);
+  async getEntity<Entity> (entity: new () => Entity, id: string, blockHash: string): Promise<any> {
+    // Get entity from the database.
+    const result = await this._database.getEntity(entity, id, blockHash) as any;
+
+    // Resolve any field name conflicts in the entity result.
+    return resolveEntityFieldConflicts(result);
   }
 }