fix: replace underpriced dapp-suggested and saved gas fees with suggested estimates

packages/transaction-controller/CHANGELOG.md

@@ -10,6 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Bump `@metamask/network-controller` from `^35.0.0` to `^35.0.1` ([#9758](https://github.com/MetaMask/core/pull/9758))
+- Replace underpriced dapp-suggested gas fees with the wallet's suggested estimates ([#9704](https://github.com/MetaMask/core/pull/9704))
+  - If the new `replaceUnderpricedDappGasFees` feature flag is enabled for the chain, dapp-suggested EIP-1559 fees with a `maxFeePerGas` below the current low estimate are replaced with the suggested medium values, as they are unlikely to result in inclusion in a block before fee values change.
+  - The `userFeeLevel` for such transactions is set to `medium` instead of `dappSuggested`, so the values are kept updated while the transaction is unapproved.
+  - The original dapp-suggested values remain available via `dappSuggestedGasFees` on the transaction metadata.
+  - Disabled by default.
+- Ignore underpriced saved (advanced) gas fee preferences in favour of the wallet's suggested estimates ([#9704](https://github.com/MetaMask/core/pull/9704))
+  - If the new `replaceUnderpricedSavedGasFees` feature flag is enabled for the chain, saved custom fees with a `maxBaseFee` below the current low estimate are ignored and the suggested medium values are used instead, as they are unlikely to result in inclusion in a block before fee values change.
+  - Level-based saved preferences track current estimates and are never ignored.
+  - The `userFeeLevel` for such transactions is set to `medium` instead of `custom`, so the values are kept updated while the transaction is unapproved.
+  - Disabled by default.
 
 ### Fixed
 

packages/transaction-controller/src/utils/feature-flags.test.ts

@@ -22,6 +22,8 @@ import {
   getTransactionHistoryLimit,
   FeatureFlag,
   getTimeoutAttempts,
+  getReplaceUnderpricedDappGasFeesEnabled,
+  getReplaceUnderpricedSavedGasFeesEnabled,
 } from './feature-flags.js';
 import { isValidSignature } from './signature.js';
 
@@ -822,6 +824,52 @@ describe('Feature Flags Utils', () => {
     });
   });
 
+  describe.each([
+    [
+      'getReplaceUnderpricedDappGasFeesEnabled',
+      getReplaceUnderpricedDappGasFeesEnabled,
+      'replaceUnderpricedDappGasFees' as const,
+    ],
+    [
+      'getReplaceUnderpricedSavedGasFeesEnabled',
+      getReplaceUnderpricedSavedGasFeesEnabled,
+      'replaceUnderpricedSavedGasFees' as const,
+    ],
+  ])('%s', (_name, getter, flagKey) => {
+    it('returns false if no feature flags set', () => {
+      mockFeatureFlags({});
+
+      expect(getter(CHAIN_ID_MOCK, controllerMessenger)).toBe(false);
+    });
+
+    it('returns default value if no chain-specific config', () => {
+      mockFeatureFlags({
+        [FeatureFlag.Transactions]: {
+          [flagKey]: {
+            default: true,
+          },
+        },
+      });
+
+      expect(getter(CHAIN_ID_MOCK, controllerMessenger)).toBe(true);
+    });
+
+    it('returns chain-specific value when available', () => {
+      mockFeatureFlags({
+        [FeatureFlag.Transactions]: {
+          [flagKey]: {
+            default: true,
+            perChainConfig: {
+              [CHAIN_ID_MOCK]: false,
+            },
+          },
+        },
+      });
+
+      expect(getter(CHAIN_ID_MOCK, controllerMessenger)).toBe(false);
+    });
+  });
+
   describe('getTimeoutAttempts', () => {
     it('returns undefined if no feature flags set', () => {
       mockFeatureFlags({});

packages/transaction-controller/src/utils/feature-flags.ts

@@ -186,6 +186,46 @@ export type TransactionControllerFeatureFlags = {
        */
       default?: number;
     };
+
+    /**
+     * Replacement of underpriced dapp-suggested gas fees.
+     * If enabled, dapp-suggested EIP-1559 fees with a `maxFeePerGas` below the
+     * current low estimate are replaced with the wallet's suggested fees, as
+     * they are unlikely to be included in a block before fee values change.
+     */
+    replaceUnderpricedDappGasFees?: {
+      /** Enablement on a per-chain basis. */
+      perChainConfig?: {
+        [chainId: Hex]: boolean;
+      };
+
+      /**
+       * Default enablement.
+       * This value is used when no specific value is found for a chain ID.
+       */
+      default?: boolean;
+    };
+
+    /**
+     * Replacement of underpriced saved (advanced) gas fee preferences.
+     * If enabled, saved custom fees with a `maxBaseFee` below the current low
+     * estimate are ignored in favour of the wallet's suggested fees, as they
+     * are unlikely to be included in a block before fee values change.
+     * Level-based saved preferences track current estimates and are never
+     * ignored.
+     */
+    replaceUnderpricedSavedGasFees?: {
+      /** Enablement on a per-chain basis. */
+      perChainConfig?: {
+        [chainId: Hex]: boolean;
+      };
+
+      /**
+       * Default enablement.
+       * This value is used when no specific value is found for a chain ID.
+       */
+      default?: boolean;
+    };
   };
 };
 
@@ -465,6 +505,54 @@ export function getTimeoutAttempts(
   );
 }
 
+/**
+ * Retrieves whether underpriced dapp-suggested gas fees should be replaced
+ * with the wallet's suggested fees.
+ *
+ * @param chainId - The chain ID.
+ * @param messenger - The controller messenger instance.
+ * @returns Whether the replacement is enabled.
+ */
+export function getReplaceUnderpricedDappGasFeesEnabled(
+  chainId: Hex,
+  messenger: TransactionControllerMessenger,
+): boolean {
+  const featureFlags = getFeatureFlags(messenger);
+
+  const replaceUnderpricedDappGasFeesFlags =
+    featureFlags?.[FeatureFlag.Transactions]?.replaceUnderpricedDappGasFees;
+
+  return (
+    replaceUnderpricedDappGasFeesFlags?.perChainConfig?.[chainId] ??
+    replaceUnderpricedDappGasFeesFlags?.default ??
+    false
+  );
+}
+
+/**
+ * Retrieves whether underpriced saved (advanced) gas fee preferences should be
+ * ignored in favour of the wallet's suggested fees.
+ *
+ * @param chainId - The chain ID.
+ * @param messenger - The controller messenger instance.
+ * @returns Whether the replacement is enabled.
+ */
+export function getReplaceUnderpricedSavedGasFeesEnabled(
+  chainId: Hex,
+  messenger: TransactionControllerMessenger,
+): boolean {
+  const featureFlags = getFeatureFlags(messenger);
+
+  const replaceUnderpricedSavedGasFeesFlags =
+    featureFlags?.[FeatureFlag.Transactions]?.replaceUnderpricedSavedGasFees;
+
+  return (
+    replaceUnderpricedSavedGasFeesFlags?.perChainConfig?.[chainId] ??
+    replaceUnderpricedSavedGasFeesFlags?.default ??
+    false
+  );
+}
+
 /**
  * Retrieves the relevant feature flags from the remote feature flag controller.
  *