Description

This pull request improves how the Bridge UI handles and displays cases where the network fee is unavailable, especially for Bitcoin (BTC) bridges. It introduces a new hook to detect unavailable network fees, updates the logic for disabling/enabling the confirm button, and adjusts messaging and analytics accordingly. The changes also include comprehensive tests for these scenarios.

Key changes:

1. Handling Network Fee Unavailability in the UI

• Added the useIsNetworkFeeUnavailable hook to detect when the network fee (especially for BTC) is unavailable and integrated it into both BridgeView and SwapsConfirmButton components. This disables the confirm button and updates the label to "Insufficient funds" when the fee is unavailable.

2. Analytics and Event Tracking

• Updated the useBridgeQuoteEvents hook and its consumers to track when the network fee is unavailable, emitting a new network_fee_unavailable warning instead of the generic insufficient gas warning.

3. Gas Fee Calculation Logic

• Modified useHasSufficientGas to use totalNetworkFee.amount for BTC quotes instead of gasFee.effective.amount, ensuring correct balance validation for Bitcoin transactions.

4. Testing and Coverage

• Added and updated tests for both the UI and hooks to cover scenarios where the BTC network fee is unavailable, ensuring proper button states, messaging, and analytics events. This includes new test cases for SwapsConfirmButton and useBridgeQuoteEvents, and additional BTC-specific tests for useHasSufficientGas.

These updates ensure that users are clearly informed when a bridge transaction cannot proceed due to unavailable network fees, especially for Bitcoin, and that analytics accurately reflect this state.

Changelog

CHANGELOG entry: fixed BTC quote when BTC quote has missing or non-positive network fee data

Related issues

Fixes: Bridging BTC is failing at the transaction crafting in certain cases

Manual testing steps

BTC quote with unavailable fee

1. Open the Bridge/Swap flow.
2. Select BTC as the source token and ETH as the destination token.
3. Enter an amount that can produce a BTC quote.
4. Simulate or reproduce a quote where the BTC network fee is 0 or unavailable.
5. Confirm the CTA shows Insufficient funds.

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Performance checks (if applicable)

• I've tested on Android
  • Ideally on a mid-range device; emulator is acceptable
• I've tested with a power user scenario
  • Use these power-user SRPs to import wallets with many accounts and tokens
• I've instrumented key operations with Sentry traces for production performance metrics
  • See trace() for usage and addToken for an example

For performance guidelines and tooling, see the Performance Guide.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.