saepenatus/packages/walletconnect/src/v2.ts

Web3-Onboard makes it simple to connect Ethereum hardware and software wallets to your dapp. Features standardised spec compliant web3 providers for all supported wallets, framework agnostic modern javascript UI with code splitting, CSS customization, mul

import type { CoreTypes } from '@walletconnect/types'
import type {
  Chain,
  ProviderAccounts,
  WalletInit,
  EIP1193Provider
} from '@web3-onboard/common'
import { isHexString, WalletConnectOptions } from './index.js'

// methods that require user interaction
const methods = [
  'eth_sendTransaction',
  'eth_signTransaction',
  'personal_sign',
  'eth_sign',
  'eth_signTypedData',
  'eth_signTypedData_v4'
]

function walletConnect(options?: WalletConnectOptions): WalletInit {
  const projectId = options?.version == 2 ? options.projectId : undefined
  if (!projectId) {
    throw new Error(
      'WalletConnect requires a projectId. Please visit https://cloud.walletconnect.com to get one.'
    )
  }

  return () => {
    return {
      label: 'WalletConnect',
      getIcon: async () => (await import('./icon.js')).default,
      getInterface: async ({ chains, EventEmitter, appMetadata }) => {
        const { ProviderRpcError, ProviderRpcErrorCode } = await import(
          '@web3-onboard/common'
        )

        const { default: EthereumProvider } = await import(
          '@walletconnect/ethereum-provider'
        )

        const { Subject, fromEvent } = await import('rxjs')
        const { takeUntil, take } = await import('rxjs/operators')

        const getMetaData = (): CoreTypes.Metadata | undefined => {
          if (!appMetadata) return undefined
          const wcMetaData: CoreTypes.Metadata = {
            name: appMetadata.name,
            description: appMetadata.description || '',
            url: appMetadata.explore || appMetadata.gettingStartedGuide || '',
            icons: []
          }

          if (appMetadata.icon !== undefined && appMetadata.icon.length) {
            wcMetaData.icons = [appMetadata.icon]
          }
          if (appMetadata.logo !== undefined && appMetadata.logo.length) {
            wcMetaData.icons = wcMetaData.icons.length
              ? [...wcMetaData.icons, appMetadata.logo]
              : [appMetadata.logo]
          }

          return wcMetaData
        }

        const connector = await EthereumProvider.init({
          projectId,
          metadata: getMetaData(),
          chains: [1], // default to mainnet
          optionalChains: chains.map(({ id }) => parseInt(id, 16)),
          optionalMethods: methods,
          rpcMap: chains
            .map(({ id, rpcUrl }) => ({ id, rpcUrl }))
            .reduce((rpcMap: Record<number, string>, { id, rpcUrl }) => {
              rpcMap[parseInt(id, 16)] = rpcUrl
              return rpcMap
            }, {})
        })

        const emitter = new EventEmitter()
        class EthProvider {
          public request: EIP1193Provider['request']
          public connector: InstanceType<typeof EthereumProvider>
          public chains: Chain[]
          public disconnect: EIP1193Provider['disconnect']
          public emit: (typeof EventEmitter)['emit']
          public on: (typeof EventEmitter)['on']
          public removeListener: (typeof EventEmitter)['removeListener']

          private disconnected$: InstanceType<typeof Subject>

          constructor({
            connector,
            chains
          }: {
            connector: InstanceType<typeof EthereumProvider>
            chains: Chain[]
          }) {
            this.emit = emitter.emit.bind(emitter)
            this.on = emitter.on.bind(emitter)
            this.removeListener = emitter.removeListener.bind(emitter)

            this.connector = connector
            this.chains = chains
            this.disconnected$ = new Subject()

            // listen for accountsChanged
            fromEvent(this.connector, 'accountsChanged', payload => payload)
              .pipe(takeUntil(this.disconnected$))
              .subscribe({
                next: accounts => {
                  this.emit('accountsChanged', accounts)
                },
                error: console.warn
              })

            // listen for chainChanged
            fromEvent(
              this.connector,
              'chainChanged',
              (payload: number) => payload
            )
              .pipe(takeUntil(this.disconnected$))
              .subscribe({
                next: chainId => {
                  const hexChainId = `0x${chainId.toString(16)}`
                  this.emit('chainChanged', hexChainId)
                },
                error: console.warn
              })

            // listen for disconnect event
            fromEvent(
              this.connector,
              'session_delete',
              (payload: string) => payload
            )
              .pipe(takeUntil(this.disconnected$))
              .subscribe({
                next: () => {
                  this.emit('accountsChanged', [])
                  this.disconnected$.next(true)
                  typeof localStorage !== 'undefined' &&
                    localStorage.removeItem('walletconnect')
                },
                error: console.warn
              })

            this.disconnect = () => {
              if (this.connector.session) this.connector.disconnect()
            }

            // load the session if it exists
            (() => {
              const session = this.connector.session
              if (session) {
                this.emit('accountsChanged', this.connector.accounts)
                this.emit('chainChanged', this.connector.chainId)
              }
            })()

            this.request = async ({ method, params }) => {
              if (method === 'eth_chainId') {
                return isHexString(this.connector.chainId)
                  ? this.connector.chainId
                  : `0x${this.connector.chainId.toString(16)}`
              }

              if (method === 'eth_requestAccounts') {
                return new Promise<ProviderAccounts>((resolve, reject) => {
                  // Check if connection is already established
                  if (!this.connector.session) {
                    // create new session
                    this.connector.connect().catch(err => {
                      console.error('err: ', err)
                      reject(
                        new ProviderRpcError({
                          code: 4001,
                          message: 'User rejected the request.'
                        })
                      )
                    })
                  } else {
                    // update ethereum provider to load accounts & chainId
                    const accounts = this.connector.accounts
                    const chainId = this.connector.chainId
                    const hexChainId = `0x${chainId.toString(16)}`
                    this.emit('chainChanged', hexChainId)
                    return resolve(accounts)
                  }
                  // Subscribe to connection events
                  fromEvent(
                    this.connector,
                    'connect',
                    (payload: { accounts: string[]; chainId: number }) =>
                      payload
                  )
                    .pipe(take(1))
                    .subscribe({
                      next: ({ accounts, chainId }) => {
                        this.emit('accountsChanged', accounts)
                        const hexChainId = isHexString(chainId)
                          ? chainId
                          : `0x${chainId.toString(16)}`
                        this.emit('chainChanged', hexChainId)
                        resolve(accounts)
                      },
                      error: reject
                    })
                })
              }

              if (method === 'eth_selectAccounts') {
                throw new ProviderRpcError({
                  code: ProviderRpcErrorCode.UNSUPPORTED_METHOD,
                  message: `The Provider does not support the requested method: ${method}`
                })
              }

              if (method == 'wallet_switchEthereumChain') {
                if (!params) {
                  throw new ProviderRpcError({
                    code: ProviderRpcErrorCode.INVALID_PARAMS,
                    message: `The Provider requires a chainId to be passed in as an argument`
                  })
                }
                const chainIdObj = params[0] as { chainId?: number }
                if (
                  !chainIdObj.hasOwnProperty('chainId') ||
                  typeof chainIdObj['chainId'] === 'undefined'
                ) {
                  throw new ProviderRpcError({
                    code: ProviderRpcErrorCode.INVALID_PARAMS,
                    message: `The Provider requires a chainId to be passed in as an argument`
                  })
                }
                return this.connector.request({
                  method: 'wallet_switchEthereumChain',
                  params: [
                    {
                      chainId: chainIdObj.chainId
                    }
                  ]
                })
              }

              return this.connector.request<Promise<any>>({
                method,
                params
              })
            }
          }
        }

        return {
          provider: new EthProvider({ chains, connector })
        }
      }
    }
  }
}

export default walletConnect