Prep for txData decoder tests

3 files changed, 27 insertions, 5 deletions

diff --git a/packages/utils/src/address_utils.ts b/packages/utils/src/address_utils.ts
index 1fc960408..318504c37 100644
--- a/packages/utils/src/address_utils.ts
+++ b/packages/utils/src/address_utils.ts
@@ -1,10 +1,13 @@
-import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
+import { addHexPrefix, stripHexPrefix, sha3 } from 'ethereumjs-util';
 import * as jsSHA3 from 'js-sha3';
 import * as _ from 'lodash';
 
+import { BigNumber } from './configured_bignumber';
+
 const BASIC_ADDRESS_REGEX = /^(0x)?[0-9a-f]{40}$/i;
 const SAME_CASE_ADDRESS_REGEX = /^(0x)?([0-9a-f]{40}|[0-9A-F]{40})$/;
 const ADDRESS_LENGTH = 40;
+const MAX_DIGITS_IN_UNSIGNED_256_INT = 78;
 
 export const addressUtils = {
     isChecksumAddress(address: string): boolean {
@@ -43,4 +46,24 @@ export const addressUtils = {
     padZeros(address: string): string {
         return addHexPrefix(_.padStart(stripHexPrefix(address), ADDRESS_LENGTH, '0'));
     },
+    /**
+     * Generates a pseudo-random 256-bit salt.
+     * The salt can be included in a 0x order, ensuring that the order generates a unique orderHash
+     * and will not collide with other outstanding orders that are identical in all other parameters.
+     * @return  A pseudo-random 256-bit number that can be used as a salt.
+     */
+    generatePseudoRandomSalt(): BigNumber {
+        // BigNumber.random returns a pseudo-random number between 0 & 1 with a passed in number of decimal places.
+        // Source: https://mikemcl.github.io/bignumber.js/#random
+        const randomNumber = BigNumber.random(MAX_DIGITS_IN_UNSIGNED_256_INT);
+        const factor = new BigNumber(10).pow(MAX_DIGITS_IN_UNSIGNED_256_INT - 1);
+        const salt = randomNumber.times(factor);
+        return salt;
+    },
+    generatePseudoRandomAddress(): string {
+        const randomBigNum = addressUtils.generatePseudoRandomSalt();
+        const randomBuff = sha3(randomBigNum.toString());
+        const randomAddress = `0x${randomBuff.slice(0, 20).toString('hex')}`;
+        return randomAddress;
+    }
 };
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index c0f15f2ab..6f1c14c83 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -13,4 +13,3 @@ export { signTypedDataUtils } from './sign_typed_data_utils';
 export import AbiEncoder = require('./abi_encoder');
 export * from './types';
 export { TransactionDecoder } from './transaction_decoder';
-export { ZeroExTransactionDecoder } from './zeroex_transaction_decoder';
diff --git a/packages/utils/src/transaction_decoder.ts b/packages/utils/src/transaction_decoder.ts
index 1ce2ea3b0..2c3b96c72 100644
--- a/packages/utils/src/transaction_decoder.ts
+++ b/packages/utils/src/transaction_decoder.ts
@@ -18,7 +18,7 @@ export class TransactionDecoder {
                 `Malformed transaction data. Must include a hex prefix '0x' and 4-byte function selector. Got '${txData}'`,
             );
         }
-        const functionSelector = calldata.substr(0, functionSelectorLength);
+        const functionSelector = txData.substr(0, functionSelectorLength);
         return functionSelector;
     }
     /**
@@ -32,9 +32,9 @@ export class TransactionDecoder {
      */
     public addABI(abiDefinitions: AbiDefinition[], contractName?: string, deploymentInfos?: DeployedContractInfo[]): void {
         // Disregard definitions that are not functions
-        const functionAbis: MethodAbi[] = _.filter(abiDefinitions, abiEntry => {
+        const functionAbis = _.filter(abiDefinitions, abiEntry => {
             return abiEntry.type === 'function';
-        });
+        }) as MethodAbi[];
         // Record function ABI's
         _.each(functionAbis, functionAbi => {
             const abiEncoder = new AbiEncoder.Method(functionAbi);