Use eth_gasPrice result for setting too low warning on custom networks (#11370)

* Use eth_gasPrice result for setting too low warning on custom networks

* Assume CustomPriceSafeForCustomNetwork when there is no custom price set (it will default to recommended)

ui/components/app/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js

@@ -28,6 +28,7 @@ import {
   getIsMainnet,
   getSendToken,
   getPreferences,
+  getIsTestnet,
   getBasicGasEstimateLoadingStatus,
   getCustomGasLimit,
   getCustomGasPrice,
@@ -36,6 +37,7 @@ import {
   isCustomPriceSafe,
   getTokenBalance,
   getSendMaxModeState,
+  isCustomPriceSafeForCustomNetwork,
   getAveragePriceEstimateInHexWEI,
   isCustomPriceExcessive,
   getIsGasEstimatesFetched,
@@ -118,6 +120,7 @@ const mapStateToProps = (state, ownProps) => {
   const showFiat = Boolean(isMainnet || showFiatInTestnets);
 
   const isSendTokenSet = Boolean(sendToken);
+  const isTestnet = getIsTestnet(state);
 
   const newTotalEth =
     maxModeOn && !isSendTokenSet
@@ -138,6 +141,16 @@ const mapStateToProps = (state, ownProps) => {
         conversionRate,
       });
   const isGasEstimate = getIsGasEstimatesFetched(state);
+
+  let customPriceIsSafe;
+  if ((isMainnet || process.env.IN_TEST) && isGasEstimate) {
+    customPriceIsSafe = isCustomPriceSafe(state);
+  } else if (isTestnet) {
+    customPriceIsSafe = true;
+  } else {
+    customPriceIsSafe = isCustomPriceSafeForCustomNetwork(state);
+  }
+
   return {
     hideBasic,
     isConfirm: isConfirm(state),
@@ -147,10 +160,7 @@ const mapStateToProps = (state, ownProps) => {
     customGasLimit: calcCustomGasLimit(customModalGasLimitInHex),
     customGasTotal,
     newTotalFiat,
-    customPriceIsSafe:
-      (isMainnet || process.env.IN_TEST) && isGasEstimate
-        ? isCustomPriceSafe(state)
-        : true,
+    customPriceIsSafe,
     customPriceIsExcessive: isCustomPriceExcessive(state),
     maxModeOn,
     gasPriceButtonGroupProps: {

ui/selectors/custom-gas.js

@@ -100,6 +100,28 @@ export function isCustomPriceSafe(state) {
   return customPriceSafe;
 }
 
+export function isCustomPriceSafeForCustomNetwork(state) {
+  const estimatedPrice = state.gas.basicEstimates.average;
+
+  const customGasPrice = getCustomGasPrice(state);
+
+  if (!customGasPrice) {
+    return true;
+  }
+
+  const customPriceSafe = conversionGreaterThan(
+    {
+      value: customGasPrice,
+      fromNumericBase: 'hex',
+      fromDenomination: 'WEI',
+      toDenomination: 'GWEI',
+    },
+    { value: estimatedPrice, fromNumericBase: 'dec' },
+  );
+
+  return customPriceSafe;
+}
+
 export function isCustomPriceExcessive(state, checkSend = false) {
   const customPrice = checkSend ? getGasPrice(state) : getCustomGasPrice(state);
   const fastPrice = getFastPriceEstimate(state);