1 files changed, 21 insertions, 3 deletions
diff --git a/packages/sol-tracing-utils/src/trace_collection_subprovider.ts b/packages/sol-tracing-utils/src/trace_collection_subprovider.ts
index 25e38768d..323e1523c 100644
--- a/packages/sol-tracing-utils/src/trace_collection_subprovider.ts
+++ b/packages/sol-tracing-utils/src/trace_collection_subprovider.ts
@@ -1,5 +1,6 @@
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0x/subproviders';
+import { logUtils } from '@0x/utils';
 import { CallDataRPC, marshaller, Web3Wrapper } from '@0x/web3-wrapper';
 import { JSONRPCRequestPayload, Provider, TxData } from 'ethereum-types';
 import * as _ from 'lodash';
@@ -20,6 +21,23 @@ export interface TraceCollectionSubproviderConfig {
     shouldCollectGasEstimateTraces: boolean;
 }
 
+type AsyncFunc = (...args: any[]) => Promise<void>;
+
+// HACK: This wrapper outputs errors to console even if the promise gets ignored
+// we need this because web3-provider-engine does not handle promises in
+// the after function of next(after).
+function logAsyncErrors(fn: AsyncFunc): AsyncFunc {
+    async function wrappedAsync(...args: any[]): Promise<void> {
+        try {
+            await fn(...args);
+        } catch (err) {
+            logUtils.log(err);
+            throw err;
+        }
+    }
+    return wrappedAsync;
+}
+
 // Because there is no notion of a call trace in the Ethereum rpc - we collect them in a rather non-obvious/hacky way.
 // On each call - we create a snapshot, execute the call as a transaction, get the trace, revert the snapshot.
 // That allows us to avoid influencing test behaviour.
@@ -74,7 +92,7 @@ export abstract class TraceCollectionSubprovider extends Subprovider {
                         next();
                     } else {
                         const txData = payload.params[0];
-                        next(this._onTransactionSentAsync.bind(this, txData));
+                        next(logAsyncErrors(this._onTransactionSentAsync.bind(this, txData)));
                     }
                     return;
 
@@ -83,7 +101,7 @@ export abstract class TraceCollectionSubprovider extends Subprovider {
                         next();
                     } else {
                         const callData = payload.params[0];
-                        next(this._onCallOrGasEstimateExecutedAsync.bind(this, callData));
+                        next(logAsyncErrors(this._onCallOrGasEstimateExecutedAsync.bind(this, callData)));
                     }
                     return;
 
@@ -92,7 +110,7 @@ export abstract class TraceCollectionSubprovider extends Subprovider {
                         next();
                     } else {
                         const estimateGasData = payload.params[0];
-                        next(this._onCallOrGasEstimateExecutedAsync.bind(this, estimateGasData));
+                        next(logAsyncErrors(this._onCallOrGasEstimateExecutedAsync.bind(this, estimateGasData)));
                     }
                     return;