Add error handling to eth_call handler

cerc-io · Sep 12, 2024 · fb7e179 · fb7e179
1 parent 8b70c22
commit fb7e179
Showing 1 changed file with 64 additions and 29 deletions.
diff --git a/packages/util/src/eth-rpc-handlers.ts b/packages/util/src/eth-rpc-handlers.ts
@@ -1,6 +1,25 @@
 /* eslint-disable @typescript-eslint/no-unused-vars */
 import { IndexerInterface } from './types';
 
+const CODE_INVALID_PARAMS = -32602;
+const CODE_INTERNAL_ERROR = -32603;
+const CODE_SERVER_ERROR = -32000;
+
+const ERROR_CONTRACT_MAP_NOT_SET = 'Contract map not set';
+const ERROR_CONTRACT_ABI_NOT_FOUND = 'Contract ABI not found';
+const ERROR_CONTRACT_INSUFFICIENT_PARAMS = 'Insufficient params';
+const ERROR_CONTRACT_NOT_RECOGNIZED = 'Contract not recognized';
+const ERROR_CONTRACT_METHOD_NOT_FOUND = 'Contract method not found';
+const ERROR_METHOD_NOT_IMPLEMENTED = 'Method not implemented';
+
+class ErrorWithCode extends Error {
+  code: number;
+  constructor (code: number, message: string) {
+    super(message);
+    this.code = code;
+  }
+}
+
 export const createEthRPCHandlers = async (
   indexer: IndexerInterface
 ): Promise<any> => {
@@ -13,48 +32,64 @@ export const createEthRPCHandlers = async (
     },
 
     eth_call: async (args: any, callback: any) => {
-      // TODO: Handle empty args
-      // TODO: Set errors in response
       // TODO: Parse blockTag
 
-      const { to, data, blockTag } = args[0];
+      try {
+        if (args.length === 0) {
+          throw new ErrorWithCode(CODE_INVALID_PARAMS, ERROR_CONTRACT_INSUFFICIENT_PARAMS);
+        }
 
-      // For values other than blockHash, resolve value from block_progress table
-      const latestBlock = await indexer.getLatestCanonicalBlock();
-      const blockHash = latestBlock?.blockHash;
+        const { to, data, blockTag } = args[0];
 
-      const watchedContract = indexer.getWatchedContracts().find(contract => contract.address === to);
-      if (!watchedContract) {
-        throw new Error('Contract not recognized');
-      }
+        if (!indexer.contractMap) {
+          throw new ErrorWithCode(CODE_INTERNAL_ERROR, ERROR_CONTRACT_MAP_NOT_SET);
+        }
 
-      if (!indexer.contractMap) {
-        throw new Error('Contract map not found');
-      }
+        // For values other than blockHash, resolve value from block_progress table
+        const latestBlock = await indexer.getLatestCanonicalBlock();
+        const blockHash = latestBlock?.blockHash;
 
-      const contractInterface = indexer.contractMap.get(watchedContract.kind);
-      if (!contractInterface) {
-        throw new Error('Contract ABI not found');
-      }
+        const watchedContract = indexer.getWatchedContracts().find(contract => contract.address === to);
+        if (!watchedContract) {
+          throw new ErrorWithCode(CODE_INVALID_PARAMS, ERROR_CONTRACT_NOT_RECOGNIZED);
+        }
 
-      // Slice out method signature
-      const functionSelector = data.slice(0, 10);
+        const contractInterface = indexer.contractMap.get(watchedContract.kind);
+        if (!contractInterface) {
+          throw new ErrorWithCode(CODE_INTERNAL_ERROR, ERROR_CONTRACT_ABI_NOT_FOUND);
+        }
 
-      // Find the matching function from the ABI
-      const functionFragment = contractInterface.getFunction(functionSelector);
-      if (!functionFragment) {
-        throw new Error('Method not found');
-      }
+        // Slice out method signature from data
+        const functionSelector = data.slice(0, 10);
+
+        // Find the matching function from the ABI
+        const functionFragment = contractInterface.getFunction(functionSelector);
+        if (!functionFragment) {
+          throw new ErrorWithCode(CODE_INVALID_PARAMS, ERROR_CONTRACT_METHOD_NOT_FOUND);
+        }
+
+        // Decode the data based on the matched function
+        const decodedData = contractInterface.decodeFunctionData(functionFragment, data);
 
-      // Decode the data based on the matched function
-      const decodedData = contractInterface.decodeFunctionData(functionFragment, data);
+        const functionName = functionFragment.name;
+        const indexerMethod = (indexer as any)[functionName].bind(indexer);
+        if (!indexerMethod) {
+          throw new ErrorWithCode(CODE_SERVER_ERROR, ERROR_METHOD_NOT_IMPLEMENTED);
+        }
 
-      const functionName = functionFragment.name;
-      const indexerMethod = (indexer as any)[functionName].bind(indexer);
-      if (indexerMethod && typeof indexerMethod === 'function') {
         const result = await indexerMethod(blockHash, to, ...decodedData);
         const encodedResult = contractInterface.encodeFunctionResult(functionFragment, [result.value]);
+
         callback(null, encodedResult);
+      } catch (error: any) {
+        let callBackError;
+        if (error instanceof ErrorWithCode) {
+          callBackError = { code: error.code, message: error.message };
+        } else {
+          callBackError = { code: CODE_SERVER_ERROR, message: error.message };
+        }
+
+        callback(callBackError);
       }
     },