2 files changed, 32 insertions, 0 deletions
diff --git a/packages/order-watcher/src/utils/assert.ts b/packages/order-watcher/src/utils/assert.ts
new file mode 100644
index 000000000..f96bcebc1
--- /dev/null
+++ b/packages/order-watcher/src/utils/assert.ts
@@ -0,0 +1,19 @@
+import { assert as sharedAssert } from '@0xproject/assert';
+// We need those two unused imports because they're actually used by sharedAssert which gets injected here
+// tslint:disable-next-line:no-unused-variable
+import { Schema } from '@0xproject/json-schemas';
+// tslint:disable-next-line:no-unused-variable
+import { ECSignature } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import * as _ from 'lodash';
+
+import { isValidSignature } from '@0xproject/order-utils';
+
+export const assert = {
+    ...sharedAssert,
+    isValidSignature(orderHash: string, ecSignature: ECSignature, signerAddress: string) {
+        const isValid = isValidSignature(orderHash, ecSignature, signerAddress);
+        this.assert(isValid, `Expected order with hash '${orderHash}' to have a valid signature`);
+    },
+};
diff --git a/packages/order-watcher/src/utils/utils.ts b/packages/order-watcher/src/utils/utils.ts
new file mode 100644
index 000000000..af1125632
--- /dev/null
+++ b/packages/order-watcher/src/utils/utils.ts
@@ -0,0 +1,13 @@
+import { BigNumber } from '@0xproject/utils';
+
+export const utils = {
+    spawnSwitchErr(name: string, value: any): Error {
+        return new Error(`Unexpected switch value: ${value} encountered for ${name}`);
+    },
+    getCurrentUnixTimestampSec(): BigNumber {
+        return new BigNumber(Date.now() / 1000).round();
+    },
+    getCurrentUnixTimestampMs(): BigNumber {
+        return new BigNumber(Date.now());
+    },
+};