Make some callbacks failable and add error handling

3 files changed, 22 insertions, 6 deletions

diff --git a/packages/0x.js/src/order_watcher/event_watcher.ts b/packages/0x.js/src/order_watcher/event_watcher.ts
index fc0b9264c..43a60957b 100644
--- a/packages/0x.js/src/order_watcher/event_watcher.ts
+++ b/packages/0x.js/src/order_watcher/event_watcher.ts
@@ -36,6 +36,10 @@ export class EventWatcher {
         this._intervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
             this._pollForBlockchainEventsAsync.bind(this, callback),
             this._pollingIntervalMs,
+            (err: Error) => {
+                this.unsubscribe();
+                callback(err);
+            },
         );
     }
     public unsubscribe(): void {
@@ -78,7 +82,7 @@ export class EventWatcher {
                 ...log,
             };
             if (!_.isUndefined(this._intervalIdIfExists)) {
-                callback(logEvent);
+                callback(null, logEvent);
             }
         }
     }
diff --git a/packages/0x.js/src/order_watcher/expiration_watcher.ts b/packages/0x.js/src/order_watcher/expiration_watcher.ts
index e7d085fc8..00b62162d 100644
--- a/packages/0x.js/src/order_watcher/expiration_watcher.ts
+++ b/packages/0x.js/src/order_watcher/expiration_watcher.ts
@@ -30,16 +30,17 @@ export class ExpirationWatcher {
         if (!_.isUndefined(this._orderExpirationCheckingIntervalIdIfExists)) {
             throw new Error(ZeroExError.SubscriptionAlreadyPresent);
         }
-        this._orderExpirationCheckingIntervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
+        this._orderExpirationCheckingIntervalIdIfExists = intervalUtils.setInterval(
             this._pruneExpiredOrders.bind(this, callback),
             this._orderExpirationCheckingIntervalMs,
+            _.noop, // _pruneExpiredOrders never throws
         );
     }
     public unsubscribe(): void {
         if (_.isUndefined(this._orderExpirationCheckingIntervalIdIfExists)) {
             throw new Error(ZeroExError.SubscriptionNotFound);
         }
-        intervalUtils.clearAsyncExcludingInterval(this._orderExpirationCheckingIntervalIdIfExists);
+        intervalUtils.clearInterval(this._orderExpirationCheckingIntervalIdIfExists);
         delete this._orderExpirationCheckingIntervalIdIfExists;
     }
     public addOrder(orderHash: string, expirationUnixTimestampMs: BigNumber): void {
diff --git a/packages/0x.js/src/order_watcher/order_state_watcher.ts b/packages/0x.js/src/order_watcher/order_state_watcher.ts
index 9d7a733d8..3543480f8 100644
--- a/packages/0x.js/src/order_watcher/order_state_watcher.ts
+++ b/packages/0x.js/src/order_watcher/order_state_watcher.ts
@@ -155,6 +155,10 @@ export class OrderStateWatcher {
         this._cleanupJobIntervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
             this._cleanupAsync.bind(this),
             this._cleanupJobInterval,
+            (err: Error) => {
+                this.unsubscribe();
+                callback(err);
+            },
         );
     }
     /**
@@ -207,11 +211,18 @@ export class OrderStateWatcher {
         if (!_.isUndefined(this._orderByOrderHash[orderHash])) {
             this.removeOrder(orderHash);
             if (!_.isUndefined(this._callbackIfExists)) {
-                this._callbackIfExists(orderState);
+                this._callbackIfExists(null, orderState);
             }
         }
     }
-    private async _onEventWatcherCallbackAsync(log: LogEvent): Promise<void> {
+    private async _onEventWatcherCallbackAsync(err: Error | null, logIfExists?: LogEvent): Promise<void> {
+        if (!_.isNull(err)) {
+            if (!_.isUndefined(this._callbackIfExists)) {
+                this._callbackIfExists(err);
+                this.unsubscribe();
+            }
+        }
+        const log = logIfExists as LogEvent;
         const maybeDecodedLog = this._abiDecoder.tryToDecodeLogOrNoop(log);
         const isLogDecoded = !_.isUndefined((maybeDecodedLog as LogWithDecodedArgs<any>).event);
         if (!isLogDecoded) {
@@ -332,7 +343,7 @@ export class OrderStateWatcher {
             } else {
                 this._orderStateByOrderHashCache[orderHash] = orderState;
             }
-            this._callbackIfExists(orderState);
+            this._callbackIfExists(null, orderState);
         }
     }
     private _addToDependentOrderHashes(signedOrder: SignedOrder, orderHash: string): void {