1 files changed, 42 insertions, 0 deletions
diff --git a/packages/instant/src/util/order_coercion.ts b/packages/instant/src/util/order_coercion.ts
new file mode 100644
index 000000000..a1b468baf
--- /dev/null
+++ b/packages/instant/src/util/order_coercion.ts
@@ -0,0 +1,42 @@
+import { BigNumber } from '@0x/utils';
+import * as _ from 'lodash';
+
+import { maybeBigNumberUtil } from './maybe_big_number';
+
+const coerceBigNumberOrString = (value: any): BigNumber => {
+    const bn = maybeBigNumberUtil.toMaybeBigNumber(value);
+    return !!bn ? bn : value;
+};
+
+// function implies that the signed order already has been validated
+export const orderCoercionUtil = {
+    // coerces order big number values to the BigNumber version utilized by 0x
+    coerceFieldsToBigNumbers(obj: any, fields: string[]): any {
+        const result = _.assign({}, obj);
+        _.each(fields, field => {
+            _.update(result, field, (value: string) => {
+                if (_.isUndefined(value)) {
+                    throw new Error(`Could not find field '${field}' while converting fields to BigNumber.`);
+                }
+                return coerceBigNumberOrString(value);
+            });
+        });
+        return result;
+    },
+
+    coerceOrderFieldsToBigNumber: (order: any): any => {
+        return orderCoercionUtil.coerceFieldsToBigNumbers(order, [
+            'makerFee',
+            'takerFee',
+            'makerAssetAmount',
+            'takerAssetAmount',
+            'salt',
+            'expirationTimeSeconds',
+        ]);
+    },
+    coerceOrderArrayFieldsToBigNumber: (orders: any[]): any[] => {
+        return _.map(orders, (value: any) => {
+            return orderCoercionUtil.coerceOrderFieldsToBigNumber(value);
+        });
+    },
+};