refactor: Refactor isTestNet to accept chain ID

The `isTestNet` utility function now accepts a chain ID rather than a
network ID. The chain ID is easier for us to access because we know the
chain ID for all networks statically, as it's a required network
configuration property. The network ID on the other hand is looked up
at runtime, and is sometimes not present.

In practice we had already been passing in chain ID as network ID in
many places This hasn't caused issues because they are equivalent for
most (though not all) networks.

This relates to MetaMask/mobile-planning#1226

app/components/UI/ApproveTransactionReview/index.js

@@ -161,10 +161,6 @@ class ApproveTransactionReview extends PureComponent {
      * Object that represents the navigator
      */
     navigation: PropTypes.object,
-    /**
-     * Network id
-     */
-    networkId: PropTypes.string,
     /**
      * True if transaction is over the available funds
      */
@@ -699,7 +695,7 @@ class ApproveTransactionReview extends PureComponent {
       gasError,
       activeTabUrl,
       transaction: { origin, from, to },
-      networkId,
+      chainId,
       over,
       gasEstimateType,
       onUpdatingValuesStart,
@@ -721,7 +717,7 @@ class ApproveTransactionReview extends PureComponent {
       isGasEstimateStatusIn,
     } = this.props;
     const styles = this.getStyles();
-    const isTestNetwork = isTestNet(networkId);
+    const isTestNetwork = isTestNet(chainId);
 
     const originIsDeeplink =
       origin === ORIGIN_DEEPLINK || origin === ORIGIN_QR_CODE;

app/components/UI/TransactionReview/TransactionReviewInformation/index.js

@@ -43,7 +43,6 @@ import AppConstants from '../../../../core/AppConstants';
 import WarningMessage from '../../../Views/SendFlow/WarningMessage';
 import {
   selectChainId,
-  selectNetwork,
   selectTicker,
 } from '../../../../selectors/networkController';
 import {
@@ -181,9 +180,9 @@ class TransactionReviewInformation extends PureComponent {
      */
     onCancelPress: PropTypes.func,
     /**
-     * Network id
+     * The chain ID for the current selected network
      */
-    networkId: PropTypes.string,
+    chainId: PropTypes.string,
     /**
      * Indicates whether custom nonce should be shown in transaction editor
      */
@@ -357,8 +356,8 @@ class TransactionReviewInformation extends PureComponent {
   };
 
   isTestNetwork = () => {
-    const { networkId } = this.props;
-    return isTestNet(networkId);
+    const { chainId } = this.props;
+    return isTestNet(chainId);
   };
 
   getRenderTotalsEIP1559 = ({
@@ -721,7 +720,7 @@ class TransactionReviewInformation extends PureComponent {
 }
 
 const mapStateToProps = (state) => ({
-  networkId: selectNetwork(state),
+  networkId: selectChainId(state),
   conversionRate: selectConversionRate(state),
   currentCurrency: selectCurrentCurrency(state),
   nativeCurrency: selectNativeCurrency(state),

app/components/Views/SendFlow/Confirm/index.js

@@ -85,7 +85,6 @@ import {
 } from '../../../../core/GasPolling/GasPolling';
 import {
   selectChainId,
-  selectNetwork,
   selectProviderType,
   selectTicker,
 } from '../../../../selectors/networkController';
@@ -166,10 +165,6 @@ class Confirm extends PureComponent {
      * Chain Id
      */
     chainId: PropTypes.string,
-    /**
-     * Network id
-     */
-    networkId: PropTypes.string,
     /**
      * Indicates whether hex data should be shown in transaction editor
      */
@@ -937,7 +932,6 @@ class Confirm extends PureComponent {
       showHexData,
       showCustomNonce,
       primaryCurrency,
-      networkId,
       chainId,
       gasEstimateType,
       isNativeTokenBuySupported,
@@ -968,7 +962,7 @@ class Confirm extends PureComponent {
       gasEstimateType === GAS_ESTIMATE_TYPES.NONE;
     const isQRHardwareWalletDevice = isQRHardwareAccount(fromSelectedAddress);
 
-    const isTestNetwork = isTestNet(networkId);
+    const isTestNetwork = isTestNet(chainId);
 
     const errorPress = isTestNetwork ? this.goToFaucet : this.buyEth;
     const errorLinkText = isTestNetwork
@@ -1144,7 +1138,6 @@ const mapStateToProps = (state) => ({
   contractBalances: selectContractBalances(state),
   conversionRate: selectConversionRate(state),
   currentCurrency: selectCurrentCurrency(state),
-  networkId: selectNetwork(state),
   providerType: selectProviderType(state),
   showHexData: state.settings.showHexData,
   showCustomNonce: state.settings.showCustomNonce,

app/util/networks/index.js

@@ -15,7 +15,11 @@ import {
   LINEA_MAINNET,
 } from '../../../app/constants/network';
 import { NetworkSwitchErrorType } from '../../../app/constants/error';
-import { query } from '@metamask/controller-utils';
+import {
+  NetworksChainId,
+  NetworkType,
+  query,
+} from '@metamask/controller-utils';
 import Engine from '../../core/Engine';
 import { toLowerCaseEquals } from '../general';
 import { fastSplit } from '../number';
@@ -178,15 +182,22 @@ export const getTestNetImageByChainId = (chainId) => {
   }
 };
 
-export const isTestNet = (networkId) => {
-  const networkName = getNetworkName(networkId);
+/**
+ * A list of chain IDs for known testnets
+ */
+const TESTNET_CHAIN_IDS = [
+  NetworksChainId[NetworkType.goerli],
+  NetworksChainId[NetworkType.sepolia],
+  NetworksChainId[NetworkType['linea-goerli']],
+];
 
-  return (
-    networkName === GOERLI ||
-    networkName === SEPOLIA ||
-    networkName === LINEA_GOERLI
-  );
-};
+/**
+ * Determine whether the given chain ID is for a known testnet.
+ *
+ * @param {string} chainId - The chain ID of the network to check
+ * @returns {boolean} `true` if the given chain ID is for a known testnet, `false` otherwise
+ */
+export const isTestNet = (chainId) => TESTNET_CHAIN_IDS.includes(chainId);
 
 export function getNetworkTypeById(id) {
   if (!id) {

app/util/networks/index.test.ts

@@ -1,5 +1,7 @@
+import { NetworksChainId, NetworkType } from '@metamask/controller-utils';
 import {
   isMainNet,
+  isTestNet,
   getNetworkName,
   getAllNetworks,
   getNetworkTypeById,
@@ -62,6 +64,24 @@ describe('NetworkUtils::isMainNet', () => {
   });
 });
 
+describe('NetworkUtils::isTestNet', () => {
+  const testnets = [
+    NetworkType.goerli,
+    NetworkType.sepolia,
+    NetworkType['linea-goerli'],
+  ];
+
+  for (const networkType of testnets) {
+    it(`should return true if the given chain ID is for '${networkType}'`, () => {
+      expect(isTestNet(NetworksChainId[networkType])).toEqual(true);
+    });
+  }
+
+  it(`should return false if the given chain ID is not a known testnet`, () => {
+    expect(isTestNet('42')).toEqual(false);
+  });
+});
+
 describe('NetworkUtils::getNetworkName', () => {
   it(`should get network name for ${MAINNET} id`, () => {
     const main = getNetworkName(String(1));