Make SwapsController support multichain

[desi]

What is this about?

Make SwapsController support multichain.

The swaps controller currently relies upon the "globally selected network". It should be refactored such that each chain interaction is made by methods that include a networkClientId parameter, which determines which network client/chain is used.

Scenario

No response

Design

No response

Technical Details

N/A

Threat Modeling Framework

N/A

Acceptance Criteria

• The controller no longer relies upon the globally selected network.
• All operations involving a chain specify a networkClientId.

Stakeholder review needed before the work gets merged

• [X] Engineering (needed in most cases)
• [ ] Design
• [ ] Product
• [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
• [ ] Security
• [ ] Legal
• [ ] Marketing
• [ ] Management (please specify)
• [ ] Other (please specify)

References

No response

[mcmire]

To implement this ticket, it seems that we would want to:

• Modify FetchTradesInfoParamsMetadata type to replace chainId with networkClientId (NOTE: this will be a breaking change because this is stored in state)
• Modify SwapsControllerOptions type to remove provider option
• Modify constructor to remove opts.provider, this.#provider, this.#ethersProvider and this.#ethersProviderChainId
• Modify fetchAndSetQuotes:
  • Replace the chainId parameter with a networkClientId parameter
  • Use NetworkController:getNetworkClientById to fetch the network client from the ID
  • Get the chain ID from the network client's configuration
  • Pass the network client to _getERC20Allowance
  • Pass the chain ID to _setSwapsNetworkConfig
  • Remove lines that set #ethersProvider and #ethersProviderChainId
• Modify getTopQuoteWithCalculatedSavings:
  • Take networkClientId in an options bag
  • Rather than reading the global chain ID, use NetworkController:getNetworkClientById to fetch the network client from the ID, then get the chain ID from the network client's configuration
  • Pass networkClientId to this.#getEIP1559GasFeeEstimates
  • Pass networkClientId (and maybe still chainId?) to #getLayer1GasFee
• Modify types for getEIP1559GasFeeEstimates and getLayer1GasFee arguments to accept a networkClientId option in an options bag
• Modify _getERC20Allowance to take a network client; create an Ethers provider on the fly before passing along to Ethers' Contract class
• Modify _setSwapsNetworkConfig to take a chain ID rather than inferring it
• Remove the #ethersProvider and #ethersProviderChainId properties
• Remove the _getCurrentChainId method
• Update tests to suit these changes
  • Add a withController helper for this controller and convert tests to use it as needed
  • Update messengerMock to add new NetworkController:getNetworkClientById as needed (might need to copy mockGetNetworkClientById helper from core?)

[mcmire]

I am going to have to revisit this to ensure that the controller is fully multichain-compatible.

• I am going to have to reorganize the existing state properties by chain.
• There are several methods that set single properties in state which do not seem to be used. I'll have to remove these.
• I'll have to update the polling logic to keep track of polls per chain. I am unsure whether I can use the PollingController since there is a custom counter that the SwapsController uses, but I'll try.
• I'll have to update any failing tests (probably all of them), rewriting any that are poorly written.

I have not updated the estimate, just noting a change in scope here. I may create a new ticket to capture this work but I will talk to the team tomorrow about it.

[mcmire]

I have asked the Swaps team whether all of what I wrote above would be necessary to complete this ticket. Waiting to hear back before continuing.

[mcmire]

Confirmed in standup today that we do need to support polling for simultaneous networks, and we are okay with overwriting state data when switching networks.