1 files changed, 23 insertions, 0 deletions
diff --git a/packages/asset-buyer/src/utils/assert.ts b/packages/asset-buyer/src/utils/assert.ts
new file mode 100644
index 000000000..c4d611477
--- /dev/null
+++ b/packages/asset-buyer/src/utils/assert.ts
@@ -0,0 +1,23 @@
+import { assert as sharedAssert } from '@0xproject/assert';
+import { schemas } from '@0xproject/json-schemas';
+import * as _ from 'lodash';
+
+import { BuyQuote, OrderFetcher } from '../types';
+
+export const assert = {
+    ...sharedAssert,
+    isValidBuyQuote(variableName: string, buyQuote: BuyQuote): void {
+        sharedAssert.isHexString(`${variableName}.assetData`, buyQuote.assetData);
+        sharedAssert.doesConformToSchema(`${variableName}.orders`, buyQuote.orders, schemas.signedOrdersSchema);
+        sharedAssert.doesConformToSchema(`${variableName}.feeOrders`, buyQuote.feeOrders, schemas.signedOrdersSchema);
+        sharedAssert.isBigNumber(`${variableName}.minRate`, buyQuote.minRate);
+        sharedAssert.isBigNumber(`${variableName}.maxRate`, buyQuote.maxRate);
+        sharedAssert.isBigNumber(`${variableName}.assetBuyAmount`, buyQuote.assetBuyAmount);
+        if (!_.isUndefined(buyQuote.feePercentage)) {
+            sharedAssert.isNumber(`${variableName}.feePercentage`, buyQuote.feePercentage);
+        }
+    },
+    isValidOrderFetcher(variableName: string, orderFetcher: OrderFetcher): void {
+        sharedAssert.isFunction(`${variableName}.fetchOrdersAsync`, orderFetcher.fetchOrdersAsync);
+    },
+};