Improve error messages when unable to find bytecode

1 files changed, 15 insertions, 2 deletions

diff --git a/packages/sol-tracing-utils/src/trace_collector.ts b/packages/sol-tracing-utils/src/trace_collector.ts
index f5dde8762..2a1f15b83 100644
--- a/packages/sol-tracing-utils/src/trace_collector.ts
+++ b/packages/sol-tracing-utils/src/trace_collector.ts
@@ -1,4 +1,5 @@
 import { promisify } from '@0x/utils';
+import chalk from 'chalk';
 import { stripHexPrefix } from 'ethereumjs-util';
 import * as fs from 'fs';
 import { Collector } from 'istanbul';
@@ -71,9 +72,21 @@ export class TraceCollector {
             : (traceInfo as TraceInfoExistingContract).runtimeBytecode;
         const contractData = utils.getContractDataIfExists(this._contractsData, bytecode);
         if (_.isUndefined(contractData)) {
+            const shortenHex = (hex: string) => {
+                /**
+                 * Length chooses so that both error messages are of the same length
+                 * and it's enough data to figure out which artifact has a problem.
+                 */
+                const length = 18;
+                return `${hex.substr(0, length + 2)}...${hex.substr(hex.length - length, length)}`;
+            };
             const errMsg = isContractCreation
-                ? `Unknown contract creation transaction`
-                : `Transaction to an unknown address: ${traceInfo.address}`;
+                ? `Unable to find matching bytecode for contract creation ${chalk.bold(
+                      shortenHex(bytecode),
+                  )}, please check your artifacts. Ignoring...`
+                : `Unable to find matching bytecode for contract address ${chalk.bold(
+                      traceInfo.address,
+                  )}, please check your artifacts. Ignoring...`;
             this._logger.warn(errMsg);
             return;
         }