1 files changed, 30 insertions, 0 deletions
diff --git a/packages/asset-buyer/src/utils/order_utils.ts b/packages/asset-buyer/src/utils/order_utils.ts
new file mode 100644
index 000000000..62166eb76
--- /dev/null
+++ b/packages/asset-buyer/src/utils/order_utils.ts
@@ -0,0 +1,30 @@
+import { SignedOrder } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+
+import { constants } from '../constants';
+
+export const orderUtils = {
+    isOrderExpired(order: SignedOrder): boolean {
+        return orderUtils.willOrderExpire(order, 0);
+    },
+    willOrderExpire(order: SignedOrder, secondsFromNow: number): boolean {
+        const millisecondsInSecond = 1000;
+        const currentUnixTimestampSec = new BigNumber(Date.now() / millisecondsInSecond).round();
+        return order.expirationTimeSeconds.lessThan(currentUnixTimestampSec.minus(secondsFromNow));
+    },
+    calculateRemainingMakerAssetAmount(order: SignedOrder, remainingTakerAssetAmount: BigNumber): BigNumber {
+        if (remainingTakerAssetAmount.eq(0)) {
+            return constants.ZERO_AMOUNT;
+        }
+        return remainingTakerAssetAmount.times(order.makerAssetAmount).dividedToIntegerBy(order.takerAssetAmount);
+    },
+    calculateRemainingTakerAssetAmount(order: SignedOrder, remainingMakerAssetAmount: BigNumber): BigNumber {
+        if (remainingMakerAssetAmount.eq(0)) {
+            return constants.ZERO_AMOUNT;
+        }
+        return remainingMakerAssetAmount.times(order.takerAssetAmount).dividedToIntegerBy(order.makerAssetAmount);
+    },
+    isOpenOrder(order: SignedOrder): boolean {
+        return order.takerAddress === constants.NULL_ADDRESS;
+    },
+};