metamask-extension/ui/app/pages/asset/asset.js

import React from 'react'
import { useSelector } from 'react-redux'
import { Redirect, useParams } from 'react-router-dom'
import { getTokens } from '../../ducks/metamask/metamask'
import { DEFAULT_ROUTE } from '../../helpers/constants/routes'

import NativeAsset from './components/native-asset'
import TokenAsset from './components/token-asset'

const Asset = () => {
  const nativeCurrency = useSelector((state) => state.metamask.nativeCurrency)
  const tokens = useSelector(getTokens)
  const { asset } = useParams()

  const token = tokens.find(({ address }) => address === asset)

  let content
  if (token) {
    content = <TokenAsset token={token} />
  } else if (asset === nativeCurrency) {
    content = <NativeAsset nativeCurrency={nativeCurrency} />
  } else {
    content = <Redirect to={{ pathname: DEFAULT_ROUTE }} />
  }
  return <div className="main-container asset__container">{content}</div>
}

export default Asset