Adds /destinationTokens route [SLT-204] (#3151)

* Adds /destinationTokens route
* ZeroAddress & NativeGasAddress
* Adds test for native gas tokens
* Checksums incoming token address params

packages/rest-api/.eslintrc.js

@@ -7,5 +7,11 @@ module.exports = {
         'prettier/prettier': 'off',
       },
     },
+    {
+      files: ['**/*.ts'],
+      rules: {
+        'guard-for-in': 'off',
+      },
+    },
   ],
 }

packages/rest-api/src/constants/bridgeable.ts

@@ -1,7 +1,6 @@
 import { BridgeableToken } from '../types'
 import { CHAINS } from './chains'
-
-const ZeroAddress = '0x0000000000000000000000000000000000000000'
+import { ZeroAddress } from '.'
 
 export const GOHM: BridgeableToken = {
   addresses: {

packages/rest-api/src/constants/index.ts

@@ -3,3 +3,6 @@ export const VALID_BRIDGE_MODULES = [
   'SynapseCCTP',
   'SynapseRFQ',
 ]
+
+export const ZeroAddress = '0x0000000000000000000000000000000000000000'
+export const NativeGasAddress = '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE'

packages/rest-api/src/controllers/destinationTokensController.ts

@@ -0,0 +1,29 @@
+import { validationResult } from 'express-validator'
+
+import { tokenAddressToToken } from '../utils/tokenAddressToToken'
+import { BRIDGE_ROUTE_MAPPING } from '../utils/bridgeRouteMapping'
+
+export const destinationTokensController = async (req, res) => {
+  const errors = validationResult(req)
+  if (!errors.isEmpty()) {
+    return res.status(400).json({ errors: errors.array() })
+  }
+
+  try {
+    const { fromChain, fromToken } = req.query
+
+    const fromTokenInfo = tokenAddressToToken(fromChain.toString(), fromToken)
+
+    const constructedKey = `${fromTokenInfo.symbol}-${fromChain}`
+
+    const options = BRIDGE_ROUTE_MAPPING[constructedKey]
+
+    res.json(options)
+  } catch (err) {
+    res.status(500).json({
+      error:
+        'An unexpected error occurred in /destinationTokens. Please try again later.',
+      details: err.message,
+    })
+  }
+}

packages/rest-api/src/middleware/checksumAddresses.ts

@@ -0,0 +1,14 @@
+import { Request, Response, NextFunction } from 'express'
+import { getAddress, isAddress } from 'ethers/lib/utils'
+
+export const checksumAddresses = (addressFields: string[]) => {
+  return (req: Request, _res: Response, next: NextFunction) => {
+    for (const field of addressFields) {
+      const address = req.query[field]
+      if (typeof address === 'string' && isAddress(address)) {
+        req.query[field] = getAddress(address)
+      }
+    }
+    next()
+  }
+}

packages/rest-api/src/routes/bridgeRoute.ts

@@ -6,11 +6,13 @@ import { CHAINS_ARRAY } from '../constants/chains'
 import { showFirstValidationError } from '../middleware/showFirstValidationError'
 import { bridgeController } from '../controllers/bridgeController'
 import { isTokenSupportedOnChain } from '../utils/isTokenSupportedOnChain'
+import { checksumAddresses } from '../middleware/checksumAddresses'
 
 const router = express.Router()
 
 router.get(
   '/',
+  checksumAddresses(['fromToken', 'toToken']),
   [
     check('fromChain')
       .isNumeric()

packages/rest-api/src/routes/bridgeTxInfoRoute.ts

@@ -7,11 +7,13 @@ import { showFirstValidationError } from '../middleware/showFirstValidationError
 import { bridgeTxInfoController } from '../controllers/bridgeTxInfoController'
 import { isTokenAddress } from '../utils/isTokenAddress'
 import { isTokenSupportedOnChain } from '../utils/isTokenSupportedOnChain'
+import { checksumAddresses } from '../middleware/checksumAddresses'
 
 const router = express.Router()
 
 router.get(
   '/',
+  checksumAddresses(['fromToken', 'toToken']),
   [
     check('fromChain')
       .isNumeric()

packages/rest-api/src/routes/destinationTokensRoute.ts

@@ -0,0 +1,40 @@
+import express from 'express'
+import { check } from 'express-validator'
+import { isAddress } from 'ethers/lib/utils'
+
+import { CHAINS_ARRAY } from '../constants/chains'
+import { showFirstValidationError } from '../middleware/showFirstValidationError'
+import { destinationTokensController } from '../controllers/destinationTokensController'
+import { isTokenAddress } from '../utils/isTokenAddress'
+import { isTokenSupportedOnChain } from '../utils/isTokenSupportedOnChain'
+import { checksumAddresses } from '../middleware/checksumAddresses'
+
+const router = express.Router()
+
+router.get(
+  '/',
+  checksumAddresses(['fromToken']),
+  [
+    check('fromChain')
+      .exists()
+      .withMessage('fromChain is required')
+      .isNumeric()
+      .custom((value) => CHAINS_ARRAY.some((c) => c.id === Number(value)))
+      .withMessage('Unsupported fromChain'),
+    check('fromToken')
+      .exists()
+      .withMessage('fromToken is required')
+      .custom((value) => isAddress(value))
+      .withMessage('Invalid fromToken address')
+      .custom((value) => isTokenAddress(value))
+      .withMessage('Unsupported fromToken address')
+      .custom((value, { req }) =>
+        isTokenSupportedOnChain(value, req.query.fromChain as string)
+      )
+      .withMessage('Token not supported on specified chain'),
+  ],
+  showFirstValidationError,
+  destinationTokensController
+)
+
+export default router

packages/rest-api/src/routes/index.ts

@@ -9,6 +9,7 @@ import getSynapseTxIdRoute from './getSynapseTxIdRoute'
 import getBridgeTxStatusRoute from './getBridgeTxStatusRoute'
 import getDestinationTxRoute from './getDestinationTxRoute'
 import tokenListRoute from './tokenListRoute'
+import destinationTokensRoute from './destinationTokensRoute'
 
 const router = express.Router()
 
@@ -21,5 +22,6 @@ router.use('/getSynapseTxId', getSynapseTxIdRoute)
 router.use('/getBridgeTxStatus', getBridgeTxStatusRoute)
 router.use('/getDestinationTx', getDestinationTxRoute)
 router.use('/tokenList', tokenListRoute)
+router.use('/destinationTokens', destinationTokensRoute)
 
 export default router

packages/rest-api/src/routes/swapRoute.ts

@@ -6,11 +6,13 @@ import { swapController } from '../controllers/swapController'
 import { CHAINS_ARRAY } from '../constants/chains'
 import { isTokenAddress } from '../utils/isTokenAddress'
 import { isTokenSupportedOnChain } from '../utils/isTokenSupportedOnChain'
+import { checksumAddresses } from '../middleware/checksumAddresses'
 
 const router = express.Router()
 
 router.get(
   '/',
+  checksumAddresses(['fromToken', 'toToken']),
   [
     check('chain')
       .isNumeric()

packages/rest-api/src/routes/swapTxInfoRoute.ts

@@ -7,11 +7,13 @@ import { showFirstValidationError } from '../middleware/showFirstValidationError
 import { swapTxInfoController } from '../controllers/swapTxInfoController'
 import { isTokenAddress } from '../utils/isTokenAddress'
 import { isTokenSupportedOnChain } from '../utils/isTokenSupportedOnChain'
+import { checksumAddresses } from '../middleware/checksumAddresses'
 
 const router = express.Router()
 
 router.get(
   '/',
+  checksumAddresses(['fromToken', 'toToken']),
   [
     check('chain')
       .isNumeric()

packages/rest-api/src/tests/destinationTokensRoute.test.ts

@@ -0,0 +1,143 @@
+import request from 'supertest'
+import express from 'express'
+
+import destinationTokensRoute from '../routes/destinationTokensRoute'
+
+const app = express()
+app.use('/destinationTokens', destinationTokensRoute)
+
+describe('destinatonTokens Route', () => {
+  it('should return destination tokens for valid input', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '1',
+      fromToken: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
+    })
+
+    expect(response.status).toBe(200)
+    expect(Array.isArray(response.body)).toBe(true)
+    expect(response.body.length).toBeGreaterThan(0)
+    expect(response.body[0]).toHaveProperty('symbol')
+    expect(response.body[0]).toHaveProperty('address')
+    expect(response.body[0]).toHaveProperty('chainId')
+  })
+
+  it('should return destination tokens for valid gas Tokens', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '1',
+      fromToken: '0x0000000000000000000000000000000000000000',
+    })
+
+    expect(response.status).toBe(200)
+    expect(Array.isArray(response.body)).toBe(true)
+    expect(response.body.length).toBeGreaterThan(0)
+    expect(response.body[0]).toHaveProperty('symbol')
+    expect(response.body[0]).toHaveProperty('address')
+    expect(response.body[0]).toHaveProperty('chainId')
+  })
+
+  it('should return precisely the number of destination tokens', async () => {
+    // 'USDC-534352': [ 'USDC-1', 'USDC-10', 'USDC-8453', 'USDC-42161', 'USDC-59144' ]
+
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '534352',
+      fromToken: '0x06eFdBFf2a14a7c8E15944D1F4A48F9F95F663A4',
+    })
+
+    expect(response.status).toBe(200)
+    expect(Array.isArray(response.body)).toBe(true)
+    expect(response.body.length).toBe(5)
+    expect(response.body[0]).toHaveProperty('symbol')
+    expect(response.body[0]).toHaveProperty('address')
+    expect(response.body[0]).toHaveProperty('chainId')
+  })
+
+  it('should return destination tokens for non-checksummed address', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '43114',
+      fromToken: '0x9702230a8ea53601f5cd2dc00fdbc13d4df4a8c7',
+    })
+
+    expect(response.status).toBe(200)
+    expect(Array.isArray(response.body)).toBe(true)
+    expect(response.body.length).toBeGreaterThan(0)
+    expect(response.body[0]).toHaveProperty('symbol')
+    expect(response.body[0]).toHaveProperty('address')
+    expect(response.body[0]).toHaveProperty('chainId')
+  })
+
+  it('should return 400 for unsupported fromChain', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '999',
+      fromToken: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'Unsupported fromChain'
+    )
+  })
+
+  it('should return 400 for invalid fromToken address', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '1',
+      fromToken: 'invalid_address',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'Invalid fromToken address'
+    )
+  })
+
+  it('should return 400 for token not supported by Synapse', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '1',
+      fromToken: '0xC011a73ee8576Fb46F5E1c5751cA3B9Fe0af2a6F',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'Unsupported fromToken address'
+    )
+  })
+
+  it('should return 400 for token not supported on specified chain', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '10',
+      fromToken: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'Token not supported on specified chain'
+    )
+  })
+
+  it('should return 400 for missing fromChain', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromToken: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'fromChain is required'
+    )
+  })
+
+  it('should return 400 for missing fromToken', async () => {
+    const response = await request(app).get('/destinationTokens').query({
+      fromChain: '1',
+    })
+
+    expect(response.status).toBe(400)
+    expect(response.body.error).toHaveProperty(
+      'message',
+      'fromToken is required'
+    )
+  })
+})