tx-gas-utils - tx-param-validation - use more intuitive check

app/scripts/lib/tx-gas-utils.js

@@ -83,11 +83,11 @@ module.exports = class txProvideUtil {
   async validateTxParams (txParams) {
     if ('value' in txParams) {
       const value = txParams.value.toString()
-      if (value.indexOf('-') === 0) {
+      if (value.includes('-')) {
         throw new Error(`Invalid transaction value of ${txParams.value} not a positive number.`)
       }
 
-      if (value.indexOf('.') >= 0) {
+      if (value.includes('.')) {
         throw new Error(`Invalid transaction value of ${txParams.value} number must be in wei`)
       }
     }