4 files changed, 26 insertions, 20 deletions

diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index d329f917a..d2d8364ca 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -12,20 +12,12 @@ import {
 import * as ethers from 'ethers';
 import * as _ from 'lodash';
 
+import { addressUtils } from './address_utils';
 import { BigNumber } from './configured_bignumber';
 
 export class AbiDecoder {
     private _savedABIs: AbiDefinition[] = [];
     private _methodIds: { [signatureHash: string]: EventAbi } = {};
-    private static _padZeros(address: string): string {
-        let formatted = address;
-        if (_.startsWith(formatted, '0x')) {
-            formatted = formatted.slice(2);
-        }
-
-        formatted = _.padStart(formatted, 40, '0');
-        return `0x${formatted}`;
-    }
     constructor(abiArrays: AbiDefinition[][]) {
         _.forEach(abiArrays, this.addABI.bind(this));
     }
@@ -45,16 +37,17 @@ export class AbiDecoder {
         const dataTypes = _.map(nonIndexedInputs, input => input.type);
         const decodedData = ethersInterface.events[event.name].parse(log.data);
 
-        let failedToDecode = false;
+        let didFailToDecode = false;
         _.forEach(event.inputs, (param: EventParameter, i: number) => {
             // Indexed parameters are stored in topics. Non-indexed ones in decodedData
             let value: BigNumber | string | number = param.indexed ? log.topics[topicsIndex++] : decodedData[i];
             if (_.isUndefined(value)) {
-                failedToDecode = true;
+                didFailToDecode = true;
                 return;
             }
             if (param.type === SolidityTypes.Address) {
-                value = AbiDecoder._padZeros(new BigNumber(value).toString(16));
+                const baseHex = 16;
+                value = addressUtils.padZeros(new BigNumber(value).toString(baseHex));
             } else if (param.type === SolidityTypes.Uint256 || param.type === SolidityTypes.Uint) {
                 value = new BigNumber(value);
             } else if (param.type === SolidityTypes.Uint8) {
@@ -63,7 +56,7 @@ export class AbiDecoder {
             decodedParams[param.name] = value;
         });
 
-        if (failedToDecode) {
+        if (didFailToDecode) {
             return log;
         } else {
             return {
diff --git a/packages/utils/src/address_utils.ts b/packages/utils/src/address_utils.ts
index f94985441..1fc960408 100644
--- a/packages/utils/src/address_utils.ts
+++ b/packages/utils/src/address_utils.ts
@@ -1,7 +1,10 @@
+import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
 import * as jsSHA3 from 'js-sha3';
+import * as _ from 'lodash';
 
 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;
 
 export const addressUtils = {
     isChecksumAddress(address: string): boolean {
@@ -9,11 +12,15 @@ export const addressUtils = {
         const unprefixedAddress = address.replace('0x', '');
         const addressHash = jsSHA3.keccak256(unprefixedAddress.toLowerCase());
 
-        for (let i = 0; i < 40; i++) {
+        for (let i = 0; i < ADDRESS_LENGTH; i++) {
             // The nth letter should be uppercase if the nth digit of casemap is 1
+            const hexBase = 16;
+            const lowercaseRange = 7;
             if (
-                (parseInt(addressHash[i], 16) > 7 && unprefixedAddress[i].toUpperCase() !== unprefixedAddress[i]) ||
-                (parseInt(addressHash[i], 16) <= 7 && unprefixedAddress[i].toLowerCase() !== unprefixedAddress[i])
+                (parseInt(addressHash[i], hexBase) > lowercaseRange &&
+                    unprefixedAddress[i].toUpperCase() !== unprefixedAddress[i]) ||
+                (parseInt(addressHash[i], hexBase) <= lowercaseRange &&
+                    unprefixedAddress[i].toLowerCase() !== unprefixedAddress[i])
             ) {
                 return false;
             }
@@ -33,4 +40,7 @@ export const addressUtils = {
             return isValidChecksummedAddress;
         }
     },
+    padZeros(address: string): string {
+        return addHexPrefix(_.padStart(stripHexPrefix(address), ADDRESS_LENGTH, '0'));
+    },
 };
diff --git a/packages/utils/src/interval_utils.ts b/packages/utils/src/interval_utils.ts
index 6984bf42d..6784d5b35 100644
--- a/packages/utils/src/interval_utils.ts
+++ b/packages/utils/src/interval_utils.ts
@@ -6,18 +6,18 @@ export const intervalUtils = {
         intervalMs: number,
         onError: (err: Error) => void,
     ): NodeJS.Timer {
-        let locked = false;
+        let isLocked = false;
         const intervalId = setInterval(async () => {
-            if (locked) {
+            if (isLocked) {
                 return;
             } else {
-                locked = true;
+                isLocked = true;
                 try {
                     await fn();
                 } catch (err) {
                     onError(err);
                 }
-                locked = false;
+                isLocked = false;
             }
         }, intervalMs);
         return intervalId;
diff --git a/packages/utils/src/log_utils.ts b/packages/utils/src/log_utils.ts
index d0f0e34c9..87f8479b5 100644
--- a/packages/utils/src/log_utils.ts
+++ b/packages/utils/src/log_utils.ts
@@ -2,4 +2,7 @@ export const logUtils = {
     log(...args: any[]): void {
         console.log(...args); // tslint:disable-line:no-console
     },
+    warn(...args: any[]): void {
+        console.warn(...args); // tslint:disable-line:no-console
+    },
 };