metamask-extension/docs/confirmation-refactoring/confirmation-pages-routing/README.md

Refactoring - Confirmation pages routing

This document details how routing to confirmation pages is currently done and the proposed improvements in routing.

Current flow

The current flow of routing to confirmation pages is un-necessarily complicated and have issues.

• There are 2 ways in which confirmation pages can be opened:
  1. User triggers send flow from within Metamask
     • If the user triggers the send flow from within MetaMask and selects the recipient and amount on the send screen, an unapproved transaction is created in the background and the user is redirected to the /confirm-transaction route.
  2. DAPP sends request to Metamask
     • If DAPP sends request to Metamask an unapproved transaction or signature request is created in background and UI is triggered open (if it is not already open).
     • The router by default renders pages/home component. The component looks at the state and if it finds an unapproved transaction or signature request in state it re-routes to /confirm-transaction.
• For /confirm-transaction/ route, the router renders pages/confirm-transaction component.
• For /confirm-transaction route pages/confirm-transaction component renders pages/confirm-transaction-switch by default, for transactions with token methods it renders pages/confirm-transaction/confirm-token-transaction-switch which also open pages/confirm-transaction-switch by default.
• pages/confirm-token-switch redirect to specific confirmation page route depending on un-approved transaction or signature request in the state.
• For specific route /confirm-transaction/${id}/XXXXX routes again pages/confirm-transaction is rendered.
• Depending on confirmation route pages/confirm-transaction and pages/confirm-transaction/confirm-token-transaction-switch renders the specific confirmation page component.

Proposed flow

The proposed routing of confirmation pages looks like.

• There are 2 ways in which confirmation pages can be opened:
  1. User triggers send flow from within Metamask
     • If the user triggers the send flow from within MetaMask and selects the recipient and amount on the send screen, an unapproved transaction is created in the background and the user is redirected to a specific transaction route, /confirm-transaction/${id}/XXXX, depending on the transaction type.
  2. DAPP sends request to Metamask
     • If DAPP send request to Metamask an unapproved transaction or signature request is created in background and UI is triggered to open (if it is not already open).
     • Instead of rendering pages/home, pages/routes finds the unapproved transaction in state and reroutes to /confirm-transaction.
• Router renders pages/confirm-transaction component for /confirm-transaction route.
• pages/confirm-transaction component redirect to specific confirmation page route depending on unapproved transaction or signature request in the state.
• Again for specific route /confirm-transaction/${id}/XXXXX pages/confirm-transaction is rendered, it in-turn renders appropriate confirmation page for the specific route.

Current Route component mapping

Route	Component
/confirm-transaction/${id}/deploy-contract	pages/confirm-deploy-contract
/confirm-transaction/${id}/send-ether	pages/confirm-send-ether
/confirm-transaction/${id}/send-token	pages/confirm-send-token
/confirm-transaction/${id}/approve	pages/confirm-approve
/confirm-transaction/${id}/set-approval-for-all	pages/confirm-approve
/confirm-transaction/${id}/transfer-from	pages/confirm-token-transaction-base
/confirm-transaction/${id}/safe-transfer-from	pages/confirm-token-transaction-base
/confirm-transaction/${id}/token-method	pages/confirm-contract-interaction
/confirm-transaction/${id}/signature-request	pages/confirm-signature-request.js

Areas of code refactoring

Current routing code is complicated, it is also currently tied to state change in confirmation pages that makes it more complicated. State refactoring as discussed in this document will also help simplify it.

• Any re-usable routing related code should be moved to useRouting hook.

• Logic to initially check state and redirect to /pages/confirm-transaction can be moved from /pages/home to pages/routes

• All the route mapping code should be moved to /pages/confirm-transaction, this will require getting rid of route mappings in /pages/confirm-transaction/confirm-token-transaction-switch, /pages/confirm-transaction-switch.

• /pages/confirm-transaction-switch has the code that checks the un-approved transaction / message in the state, and based on its type and asset redirect to a specific route, a utility method can be created to do this mapping and can be included in /pages/confirm-transaction component.

• During the send flow initiated within metamask user can be redirected to specific confirmations route /confirm-transaction/${id}/XXXX

• Confirmation components have lot of props passing which needs to be reduced. Values can be obtained from redux state or other contexts directly using hooks. Component confirm-token-transaction-switch has a lot of un-necessary props passing which should be removed and will help to further refactor routing.

• Routing to mostRecentOverviewPage Across confirmation pages there is code to re-direct to mostRecentOverviewPage. mostRecentOverviewPage is equal to default route / or /asset whichever was last opened. Also a lot of components check for state update and as soon as state has 0 pending un-approved transaction or signature request redirect is done to mostRecentOverviewPage. This logic can be handled at /pages/confirm-transaction which is always rendered for any confirmation page. Also when the transaction is completed / rejected redirect is done to mostRecentOverviewPage explicitly which we should continue to do.