Use legacy gas API for BSC (#19763)

The legacy gas API is still useful for BSC, which is a network our APIs
support that is not EIP-1559 compatible. The legacy gas API will now be
used for BSC prior to using RPC methods as a fallback.

This brings extension closer in alignment with mobile, which also uses
the legacy gas API for BSC.

The E2E network mock function has been updated to use a variable for
the initial test network. This made it easier to write the e2e test for
the BSC case.

app/scripts/metamask-controller.js

@@ -568,8 +568,12 @@ export default class MetamaskController extends EventEmitter {
         ),
       getCurrentAccountEIP1559Compatibility:
         this.getCurrentAccountEIP1559Compatibility.bind(this),
+      legacyAPIEndpoint: `${gasApiBaseUrl}/networks/<chain_id>/gasPrices`,
       EIP1559APIEndpoint: `${gasApiBaseUrl}/networks/<chain_id>/suggestedGasFees`,
-      getCurrentNetworkLegacyGasAPICompatibility: () => false,
+      getCurrentNetworkLegacyGasAPICompatibility: () => {
+        const { chainId } = this.networkController.state.providerConfig;
+        return chainId === CHAIN_IDS.BSC;
+      },
       getChainId: () => this.networkController.state.providerConfig.chainId,
     });
 

test/e2e/helpers.js

@@ -105,7 +105,9 @@ async function withFixtures(options, testSuite) {
         });
       }
     }
-    const mockedEndpoint = await setupMocking(mockServer, testSpecificMock);
+    const mockedEndpoint = await setupMocking(mockServer, testSpecificMock, {
+      chainId: ganacheOptions?.chainId || 1337,
+    });
     await mockServer.start(8000);
 
     driver = (await buildWebDriver(driverOptions)).driver;

test/e2e/mock-e2e.js

@@ -20,7 +20,16 @@ const emptyStalelist = {
   lastUpdated: 0,
 };
 
-async function setupMocking(server, testSpecificMock) {
+/**
+ * Setup E2E network mocks.
+ *
+ * @param {object} server - The mock server used for network mocks.
+ * @param {Function} testSpecificMock - A function for setting up test-specific network mocks
+ * @param {object} options - Network mock options.
+ * @param {string} options.chainId - The chain ID used by the default configured network.
+ * @returns
+ */
+async function setupMocking(server, testSpecificMock, { chainId }) {
   await server.forAnyRequest().thenPassThrough({
     beforeRequest: (req) => {
       const { host } = req.headers;
@@ -99,7 +108,9 @@ async function setupMocking(server, testSpecificMock) {
     });
 
   await server
-    .forGet('https://gas-api.metaswap.codefi.network/networks/1337/gasPrices')
+    .forGet(
+      `https://gas-api.metaswap.codefi.network/networks/${chainId}/gasPrices`,
+    )
     .thenCallback(() => {
       return {
         statusCode: 200,
@@ -130,7 +141,7 @@ async function setupMocking(server, testSpecificMock) {
 
   await server
     .forGet(
-      'https://gas-api.metaswap.codefi.network/networks/1337/suggestedGasFees',
+      `https://gas-api.metaswap.codefi.network/networks/${chainId}/suggestedGasFees`,
     )
     .thenCallback(() => {
       return {
@@ -203,7 +214,7 @@ async function setupMocking(server, testSpecificMock) {
     });
 
   await server
-    .forGet('https://token-api.metaswap.codefi.network/tokens/1337')
+    .forGet(`https://token-api.metaswap.codefi.network/tokens/${chainId}`)
     .thenCallback(() => {
       return {
         statusCode: 200,
@@ -343,7 +354,7 @@ async function setupMocking(server, testSpecificMock) {
     });
 
   await server
-    .forGet('https://token-api.metaswap.codefi.network/token/1337')
+    .forGet(`https://token-api.metaswap.codefi.network/token/${chainId}`)
     .thenCallback(() => {
       return {
         statusCode: 200,
@@ -352,11 +363,11 @@ async function setupMocking(server, testSpecificMock) {
     });
 
   // It disables loading of token icons, e.g. this URL: https://static.metafi.codefi.network/api/v1/tokenIcons/1337/0x0000000000000000000000000000000000000000.png
-  await server
+  const tokenIconRegex = new RegExp(
-    .forGet(
+    `^https:\\/\\/static\\.metafi\\.codefi\\.network\\/api\\/vi\\/tokenIcons\\/${chainId}\\/.*\\.png`,
-      /^https:\/\/static\.metafi\.codefi\.network\/api\/v1\/tokenIcons\/1337\/.*\.png/u,
+    'u',
-    )
+  );
-    .thenCallback(() => {
+  await server.forGet(tokenIconRegex).thenCallback(() => {
     return {
       statusCode: 200,
     };

test/e2e/tests/gas-estimates.spec.js

@@ -4,6 +4,7 @@ const {
   logInWithBalanceValidation,
 } = require('../helpers');
 const FixtureBuilder = require('../fixture-builder');
+const { CHAIN_IDS } = require('../../../shared/constants/network');
 
 describe('Gas estimates generated by MetaMask', function () {
   const baseGanacheOptions = {
@@ -139,7 +140,85 @@ describe('Gas estimates generated by MetaMask', function () {
   });
 
   describe('Send on a network that is not EIP-1559 compatible', function () {
-    it('show expected gas defaults', async function () {
+    it('show expected gas defaults on a network supported by legacy gas API', async function () {
+      await withFixtures(
+        {
+          fixtures: new FixtureBuilder().build(),
+          ganacheOptions: {
+            ...preLondonGanacheOptions,
+            chainId: parseInt(CHAIN_IDS.BSC, 16),
+          },
+          title: this.test.title,
+        },
+        async ({ driver, ganacheServer }) => {
+          await driver.navigate();
+          await logInWithBalanceValidation(driver, ganacheServer);
+
+          await driver.clickElement('[data-testid="eth-overview-send"]');
+
+          await driver.fill(
+            'input[placeholder="Enter public address (0x) or ENS name"]',
+            '0x2f318C334780961FB129D2a6c30D0763d9a5C970',
+          );
+
+          await driver.fill('.unit-input__input', '1');
+
+          // Check that the gas estimation is what we expect
+          await driver.findElement({
+            cass: '[data-testid="confirm-gas-display"]',
+            text: '0.000042',
+          });
+        },
+      );
+    });
+
+    it('show expected gas defaults on a network supported by legacy gas API when that API is down', async function () {
+      await withFixtures(
+        {
+          fixtures: new FixtureBuilder().build(),
+          ganacheOptions: {
+            ...preLondonGanacheOptions,
+            chainId: parseInt(CHAIN_IDS.BSC, 16),
+          },
+          testSpecificMock: (mockServer) => {
+            mockServer
+              .forGet(
+                `https://gas-api.metaswap.codefi.network/networks/${parseInt(
+                  CHAIN_IDS.BSC,
+                  16,
+                )}/gasPrices`,
+              )
+              .thenCallback(() => {
+                return {
+                  statusCode: 422,
+                };
+              });
+          },
+          title: this.test.title,
+        },
+        async ({ driver, ganacheServer }) => {
+          await driver.navigate();
+          await logInWithBalanceValidation(driver, ganacheServer);
+
+          await driver.clickElement('[data-testid="eth-overview-send"]');
+
+          await driver.fill(
+            'input[placeholder="Enter public address (0x) or ENS name"]',
+            '0x2f318C334780961FB129D2a6c30D0763d9a5C970',
+          );
+
+          await driver.fill('.unit-input__input', '1');
+
+          // Check that the gas estimation is what we expect
+          await driver.findElement({
+            cass: '[data-testid="confirm-gas-display"]',
+            text: '0.000042',
+          });
+        },
+      );
+    });
+
+    it('show expected gas defaults on a network not supported by legacy gas API', async function () {
       await withFixtures(
         {
           fixtures: new FixtureBuilder().build(),