Refactor UNLIMITED_ALLOWANCE_IN_BASE_UNITS to constants

src/contract_wrappers/token_wrapper.ts

@@ -29,7 +29,7 @@ const ALLOWANCE_TO_ZERO_GAS_AMOUNT = 47155;
  * to the 0x Proxy smart contract.
  */
 export class TokenWrapper extends ContractWrapper {
-    public UNLIMITED_ALLOWANCE_IN_BASE_UNITS = new BigNumber(2).pow(256).minus(1);
+    public UNLIMITED_ALLOWANCE_IN_BASE_UNITS = constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
     private _tokenContractsByAddress: {[address: string]: TokenContract};
     private _tokenLogEventEmitters: ContractEventEmitter[];
     constructor(web3Wrapper: Web3Wrapper) {

src/utils/constants.ts

@@ -1,7 +1,10 @@
+import * as BigNumber from 'bignumber.js';
+
 export const constants = {
     NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
     TESTRPC_NETWORK_ID: 50,
     MAX_DIGITS_IN_UNSIGNED_256_INT: 78,
     INVALID_JUMP_PATTERN: 'invalid JUMP at',
     OUT_OF_GAS_PATTERN: 'out of gas',
+    UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
 };