Add signature specific validation methods, and other refactors

1 files changed, 13 insertions, 1 deletions

diff --git a/packages/order-utils/src/assert.ts b/packages/order-utils/src/assert.ts
index 07cde453a..a1318b9b8 100644
--- a/packages/order-utils/src/assert.ts
+++ b/packages/order-utils/src/assert.ts
@@ -3,11 +3,13 @@ import { assert as sharedAssert } from '@0xproject/assert';
 // 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 { ECSignature, SignatureType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as _ from 'lodash';
 
+import { utils } from './utils';
+
 export const assert = {
     ...sharedAssert,
     async isSenderAddressAsync(
@@ -22,4 +24,14 @@ export const assert = {
             `Specified ${variableName} ${senderAddressHex} isn't available through the supplied web3 provider`,
         );
     },
+    isOneOfExpectedSignatureTypes(signature: string, signatureTypes: SignatureType[]): void {
+        sharedAssert.isHexString('signature', signature);
+        const signatureTypeIndexIfExists = utils.getSignatureTypeIndexIfExists(signature);
+        const isExpectedSignatureType = _.includes(signatureTypes, signatureTypeIndexIfExists);
+        if (!isExpectedSignatureType) {
+            throw new Error(
+                `Unexpected signatureType: ${signatureTypeIndexIfExists}. Valid signature types: ${signatureTypes}`,
+            );
+        }
+    },
 };