1 files changed, 31 insertions, 0 deletions
diff --git a/packages/0x.js/src/utils/assert.ts b/packages/0x.js/src/utils/assert.ts
new file mode 100644
index 000000000..2588a4d09
--- /dev/null
+++ b/packages/0x.js/src/utils/assert.ts
@@ -0,0 +1,31 @@
+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`);
+    },
+    async isSenderAddressAsync(
+        variableName: string,
+        senderAddressHex: string,
+        web3Wrapper: Web3Wrapper,
+    ): Promise<void> {
+        sharedAssert.isETHAddressHex(variableName, senderAddressHex);
+        const isSenderAddressAvailable = await web3Wrapper.isSenderAddressAvailableAsync(senderAddressHex);
+        sharedAssert.assert(
+            isSenderAddressAvailable,
+            `Specified ${variableName} ${senderAddressHex} isn't available through the supplied web3 provider`,
+        );
+    },
+};