Add convertToJSONSchemaCompatibleObject method

3 files changed, 15 insertions, 2 deletions

diff --git a/src/0x.js.ts b/src/0x.js.ts
index e5eb6b520..92a5d2c54 100644
--- a/src/0x.js.ts
+++ b/src/0x.js.ts
@@ -11,6 +11,7 @@ import {Web3Wrapper} from './web3_wrapper';
 import {constants} from './utils/constants';
 import {utils} from './utils/utils';
 import {assert} from './utils/assert';
+import {SchemaValidator} from './utils/schema_validator';
 import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper';
 import {TokenRegistryWrapper} from './contract_wrappers/token_registry_wrapper';
 import {ecSignatureSchema} from './schemas/ec_signature_schema';
@@ -33,7 +34,9 @@ export class ZeroEx {
      * Computes the orderHash given the order parameters and returns it as a hex encoded string.
      */
     public static getOrderHashHex(exchangeContractAddr: string, order: Order): string {
-        assert.doesConformToSchema('order', JSON.parse(JSON.stringify(order)), orderSchema);
+        assert.doesConformToSchema('order',
+                                   SchemaValidator.convertToJSONSchemaCompatibleObject(order as object),
+                                   orderSchema);
         const taker = _.isEmpty(order.taker) ? constants.NULL_ADDRESS : order.taker ;
 
         const orderParts = [
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index 754210778..59e6c755e 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -14,6 +14,7 @@ import {ContractWrapper} from './contract_wrapper';
 import * as ExchangeArtifacts from '../artifacts/Exchange.json';
 import {ecSignatureSchema} from '../schemas/ec_signature_schema';
 import {signedOrderSchema} from '../schemas/signed_order_schema';
+import {SchemaValidator} from '../utils/schema_validator';
 import {ContractResponse} from '../types';
 import {constants} from '../utils/constants';
 
@@ -56,7 +57,9 @@ export class ExchangeWrapper extends ContractWrapper {
     }
     public async fillOrderAsync(signedOrder: SignedOrder, fillAmount: BigNumber.BigNumber,
                                 shouldCheckTransfer: boolean = true): Promise<void> {
-        assert.doesConformToSchema('signedOrder', JSON.parse(JSON.stringify(signedOrder)), signedOrderSchema);
+        assert.doesConformToSchema('signedOrder',
+                                   SchemaValidator.convertToJSONSchemaCompatibleObject(signedOrder as object),
+                                   signedOrderSchema);
         assert.isBigNumber('fillAmount', fillAmount);
         assert.isBoolean('shouldCheckTransfer', shouldCheckTransfer);
 
diff --git a/src/utils/schema_validator.ts b/src/utils/schema_validator.ts
index cf45d0343..9ff7259d9 100644
--- a/src/utils/schema_validator.ts
+++ b/src/utils/schema_validator.ts
@@ -5,6 +5,13 @@ import {tokenSchema} from '../schemas/token_schema';
 
 export class SchemaValidator {
     private validator: Validator;
+    // In order to validate a complex JS object using jsonschema, we must replace any complex
+    // sub-types (e.g BigNumber) with a simpler string represenation. Since BigNumber and other
+    // complex types implement the `toString` method, we can stringify the object and
+    // then parse it. The resultant object can then be checked using jsonschema.
+    public static convertToJSONSchemaCompatibleObject(obj: object): object {
+        return JSON.parse(JSON.stringify(obj));
+    }
     constructor() {
         this.validator = new Validator();
         this.validator.addSchema(tokenSchema, tokenSchema.id);