feat: add prerequisite checks before swap (#588)

* feat: add prerequisite checks before swap

* fix: add missing authentication on desktop config call

* refactor(wip): introduce swap error

* refactor: use wrapWithSwapError

* fix: log originalError instead of error

* fix: show snackbar when error is unexpected

src/hooks/apiHooks.tsx

@@ -1,8 +1,7 @@
 import axios from 'axios'
 import { useEffect, useState } from 'react'
-import { getLatestBeeDesktopVersion } from '../utils/desktop'
-import { getJson } from '../utils/net'
 import { GITHUB_REPO_URL } from '../constants'
+import { BeeConfig, getDesktopConfiguration, getLatestBeeDesktopVersion } from '../utils/desktop'
 
 export interface LatestBeeReleaseHook {
   latestBeeRelease: LatestBeeRelease | null
@@ -109,22 +108,6 @@ export function useNewBeeDesktopVersion(
   return { newBeeDesktopVersion }
 }
 
-export interface BeeConfig {
-  'api-addr': string
-  'debug-api-addr': string
-  'debug-api-enable': boolean
-  password: string
-  'swap-enable': boolean
-  'swap-initial-deposit': bigint
-  mainnet: boolean
-  'full-node': boolean
-  'cors-allowed-origins': string
-  'resolver-options': string
-  'use-postage-snapshot': boolean
-  'data-dir': string
-  'swap-endpoint'?: string
-}
-
 export interface GetBeeConfig {
   config: BeeConfig | null
   isLoading: boolean
@@ -137,7 +120,7 @@ export const useGetBeeConfig = (desktopUrl: string): GetBeeConfig => {
   const [error, setError] = useState<Error | null>(null)
 
   useEffect(() => {
-    getJson<BeeConfig>(`${desktopUrl}/config`)
+    getDesktopConfiguration(desktopUrl)
       .then(beeConf => {
         setBeeConfig(beeConf)
         setError(null)

src/pages/top-up/Swap.tsx

@@ -20,12 +20,22 @@ import { Context as SettingsContext } from '../../providers/Settings'
 import { Context as BalanceProvider } from '../../providers/WalletBalance'
 import { ROUTES } from '../../routes'
 import { sleepMs } from '../../utils'
-import { getBzzPriceAsDai, performSwap, restartBeeNode, upgradeToLightNode } from '../../utils/desktop'
+import {
+  getBzzPriceAsDai,
+  getDesktopConfiguration,
+  performSwap,
+  restartBeeNode,
+  upgradeToLightNode,
+} from '../../utils/desktop'
+import { Rpc } from '../../utils/rpc'
+import { isSwapError, SwapError, wrapWithSwapError } from '../../utils/SwapError'
 import { TopUpProgressIndicator } from './TopUpProgressIndicator'
 
 const MINIMUM_XDAI = '0.1'
 const MINIMUM_XBZZ = '0.1'
 
+const GENERIC_SWAP_FAILED_ERROR_MESSAGE = 'Failed to swap. The full error is printed to the console.'
+
 interface Props {
   header: string
 }
@@ -127,6 +137,22 @@ export function Swap({ header }: Props): ReactElement {
     }
   }
 
+  async function performSwapWithChecks(daiToSwap: DaiToken) {
+    const desktopConfiguration = await wrapWithSwapError(
+      getDesktopConfiguration(desktopUrl),
+      'Unable to reach Desktop API. Is Swarm Desktop running?',
+    )
+
+    if (!desktopConfiguration['swap-endpoint']) {
+      throw new SwapError('Swap endpoint is not configured in Swarm Desktop')
+    }
+    await wrapWithSwapError(
+      Rpc.getNetworkChainId(desktopConfiguration['swap-endpoint']),
+      `Swap endpoint not reachable at ${desktopConfiguration['swap-endpoint']}`,
+    )
+    await wrapWithSwapError(performSwap(desktopUrl, daiToSwap.toString), GENERIC_SWAP_FAILED_ERROR_MESSAGE)
+  }
+
   async function onSwap() {
     if (hasSwapped || !daiToSwap) {
       return
@@ -135,16 +161,26 @@ export function Swap({ header }: Props): ReactElement {
     setSwapped(true)
 
     try {
-      await performSwap(desktopUrl, daiToSwap.toString)
+      await performSwapWithChecks(daiToSwap)
       const message = canUpgradeToLightNode
         ? 'Successfully swapped. Beginning light node upgrade...'
-        : 'Successfully swapped. Balances will refresh soon. You may now leave the page.'
+        : 'Successfully swapped. Balances will refresh soon. You may now navigate away.'
       enqueueSnackbar(message, { variant: 'success' })
 
       if (canUpgradeToLightNode) await restart()
     } catch (error) {
-      console.error(error) // eslint-disable-line
-      enqueueSnackbar(`Failed to swap: ${error}`, { variant: 'error' })
+      if (isSwapError(error)) {
+        // we have a custom and user friendly error message
+        enqueueSnackbar(error.snackbarMessage, { variant: 'error' })
+
+        if (error.originalError) {
+          console.error(error.originalError) // eslint-disable-line
+        }
+      } else {
+        // we have an unexpected error
+        enqueueSnackbar(`${GENERIC_SWAP_FAILED_ERROR_MESSAGE} ${error}`, { variant: 'error' })
+        console.error(error) // eslint-disable-line
+      }
     } finally {
       balance?.refresh()
       setLoading(false)

src/utils/SwapError.ts

@@ -0,0 +1,21 @@
+export class SwapError extends Error {
+  snackbarMessage: string
+  originalError?: Error
+
+  constructor(snackbarMessage: string, error?: Error) {
+    super(error?.message || snackbarMessage)
+    this.name = 'SwapError'
+    this.originalError = error
+    this.snackbarMessage = snackbarMessage
+  }
+}
+
+export function isSwapError(error: unknown): error is SwapError {
+  return error instanceof Error && error.name === 'SwapError'
+}
+
+export function wrapWithSwapError<T>(promise: Promise<T>, snackbarMessage: string): Promise<T> {
+  return promise.catch((error: Error) => {
+    throw new SwapError(snackbarMessage, error)
+  })
+}

src/utils/desktop.ts

@@ -2,7 +2,23 @@ import axios from 'axios'
 import { BEE_DESKTOP_LATEST_RELEASE_PAGE_API } from '../constants'
 import { DaiToken } from '../models/DaiToken'
 import { Token } from '../models/Token'
-import { postJson } from './net'
+import { getJson, postJson } from './net'
+
+export interface BeeConfig {
+  'api-addr': string
+  'debug-api-addr': string
+  'debug-api-enable': boolean
+  password: string
+  'swap-enable': boolean
+  'swap-initial-deposit': bigint
+  mainnet: boolean
+  'full-node': boolean
+  'cors-allowed-origins': string
+  'resolver-options': string
+  'use-postage-snapshot': boolean
+  'data-dir': string
+  'swap-endpoint'?: string
+}
 
 export async function getBzzPriceAsDai(desktopUrl: string): Promise<Token> {
   const response = await axios.get(`${desktopUrl}/price`)
@@ -23,6 +39,10 @@ export async function setJsonRpcInDesktop(desktopUrl: string, value: string): Pr
   })
 }
 
+export function getDesktopConfiguration(desktopUrl: string): Promise<BeeConfig> {
+  return getJson(`${desktopUrl}/config`)
+}
+
 async function updateDesktopConfiguration(desktopUrl: string, values: Record<string, unknown>): Promise<void> {
   await postJson(`${desktopUrl}/config`, values)
 }

src/utils/rpc.ts

@@ -2,6 +2,16 @@ import { debounce } from '@material-ui/core'
 import { Contract, providers, Wallet, BigNumber as BN } from 'ethers'
 import { bzzABI, BZZ_TOKEN_ADDRESS } from './bzz-abi'
 
+const NETWORK_ID = 100
+
+async function getNetworkChainId(url: string): Promise<number> {
+  const provider = new providers.JsonRpcProvider(url, NETWORK_ID)
+  await provider.ready
+  const network = await provider.getNetwork()
+
+  return network.chainId
+}
+
 async function eth_getBalance(address: string, provider: providers.JsonRpcProvider): Promise<string> {
   if (!address.startsWith('0x')) {
     address = `0x${address}`
@@ -78,7 +88,7 @@ export async function sendBzzTransaction(
 }
 
 async function makeReadySigner(privateKey: string, jsonRpcProvider: string) {
-  const provider = new providers.JsonRpcProvider(jsonRpcProvider, 100)
+  const provider = new providers.JsonRpcProvider(jsonRpcProvider, NETWORK_ID)
   await provider.ready
   const signer = new Wallet(privateKey, provider)
 
@@ -86,6 +96,7 @@ async function makeReadySigner(privateKey: string, jsonRpcProvider: string) {
 }
 
 export const Rpc = {
+  getNetworkChainId,
   sendNativeTransaction,
   sendBzzTransaction,
   _eth_getBalance: eth_getBalance,