Common gasprice (#179)

* Common gas price normalization.

* only e2e jobs

* One func

* More extraction.

* Fixed the tests

* skip gasPriceWithinLimits

* test fix

* tos tring

* boundaries

* Extracted fetching gas price from contract

* Refactored oracle gas price

* lint

* lint

* Commentary

* Using common gas price from oracle in ui

* Fix lint

* lint

* Log

* Using common gas price in monitor

* cosmetics

* all jobs

* lint

* lint

* tests

* more tests

* incljdes

* Tests in oracle

* Tests in commons

* Lint

* moved tests from ui to commons

* chai

* Changed order of fetching gas price

commons/.eslintrc

@@ -4,7 +4,8 @@
     "../.eslintrc"
   ],
   "rules": {
-    "no-unused-expressions": "off"
+    "no-unused-expressions": "off",
+    "import/no-extraneous-dependencies": "off"
   },
   "env": {
     "mocha": true

commons/package.json

@@ -6,5 +6,8 @@
   "scripts": {
     "lint": "eslint . --ignore-path ../.eslintignore",
     "test": "NODE_ENV=test mocha"
+  },
+  "dependencies": {
+    "web3-utils": "1.0.0-beta.30"
   }
 }

commons/test/gas.js

@@ -0,0 +1,162 @@
+const { expect } = require('chai')
+const Web3Utils = require('web3-utils')
+const { gasPriceWithinLimits, normalizeGasPrice } = require('..')
+
+const GAS_PRICE_BOUNDARIES = {
+  MIN: 1,
+  MAX: 250
+}
+
+describe('gas', () => {
+  describe('normalizeGasPrice', () => {
+    it('should work with oracle gas price in gwei', () => {
+      // Given
+      const oracleGasPrice = 30
+      const factor = 1
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('30000000000')
+    })
+    it('should work with oracle gas price not in gwei', () => {
+      // Given
+      const oracleGasPrice = 300
+      const factor = 0.1
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('30000000000')
+    })
+    it('should increase gas price value from oracle', () => {
+      // Given
+      const oracleGasPrice = 20
+      const factor = 1.5
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('30000000000')
+    })
+  })
+
+  describe('gasPriceWithinLimits', () => {
+    it('should return gas price if gas price is between boundaries', () => {
+      // given
+      const minGasPrice = 1
+      const middleGasPrice = 10
+      const maxGasPrice = 250
+
+      // when
+      const minGasPriceWithinLimits = gasPriceWithinLimits(minGasPrice, GAS_PRICE_BOUNDARIES)
+      const middleGasPriceWithinLimits = gasPriceWithinLimits(middleGasPrice, GAS_PRICE_BOUNDARIES)
+      const maxGasPriceWithinLimits = gasPriceWithinLimits(maxGasPrice, GAS_PRICE_BOUNDARIES)
+
+      // then
+      expect(minGasPriceWithinLimits).to.equal(minGasPrice)
+      expect(middleGasPriceWithinLimits).to.equal(middleGasPrice)
+      expect(maxGasPriceWithinLimits).to.equal(maxGasPrice)
+    })
+
+    it('should return min limit if gas price is below min boundary', () => {
+      // Given
+      const initialGasPrice = 0.5
+
+      // When
+      const gasPrice = gasPriceWithinLimits(initialGasPrice, GAS_PRICE_BOUNDARIES)
+
+      // Then
+      expect(gasPrice).to.equal(GAS_PRICE_BOUNDARIES.MIN)
+    })
+
+    it('should return max limit if gas price is above max boundary', () => {
+      // Given
+      const initialGasPrice = 260
+
+      // When
+      const gasPrice = gasPriceWithinLimits(initialGasPrice, GAS_PRICE_BOUNDARIES)
+
+      // Then
+      expect(gasPrice).to.equal(GAS_PRICE_BOUNDARIES.MAX)
+    })
+
+    it('should return gas price if boundaries not provided', () => {
+      // Given
+      const initialGasPrice = 260
+
+      // When
+      const gasPrice = gasPriceWithinLimits(initialGasPrice)
+
+      // Then
+      expect(gasPrice).to.equal(initialGasPrice)
+    })
+  })
+
+  describe('normalizeGasPrice', () => {
+    it('should work with oracle gas price in gwei', () => {
+      // Given
+      const oracleGasPrice = 20
+      const factor = 1
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('20000000000')
+    })
+
+    it('should work with oracle gas price not in gwei', () => {
+      // Given
+      const oracleGasPrice = 200
+      const factor = 0.1
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('20000000000')
+    })
+
+    it('should increase gas price value from oracle', () => {
+      // Given
+      const oracleGasPrice = 20
+      const factor = 1.5
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor).toString()
+
+      // Then
+      expect(result).to.equal('30000000000')
+    })
+
+    it('should respect gas price max limit', () => {
+      // Given
+      const oracleGasPrice = 200
+      const factor = 4
+      const maxInWei = Web3Utils.toWei(GAS_PRICE_BOUNDARIES.MAX.toString(), 'gwei')
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor, GAS_PRICE_BOUNDARIES).toString()
+
+      // Then
+      expect(result).to.equal(maxInWei)
+    })
+
+    it('should respect gas price min limit', () => {
+      // Given
+      const oracleGasPrice = 1
+      const factor = 0.01
+      const minInWei = Web3Utils.toWei(GAS_PRICE_BOUNDARIES.MIN.toString(), 'gwei')
+
+      // When
+      const result = normalizeGasPrice(oracleGasPrice, factor, GAS_PRICE_BOUNDARIES).toString()
+
+      // Then
+      expect(result).to.equal(minInWei)
+    })
+  })
+})

commons/utils.js

@@ -1,3 +1,4 @@
+const { toWei, toBN } = require('web3-utils')
 const { BRIDGE_MODES, FEE_MANAGER_MODE, ERC_TYPES } = require('./constants')
 
 function decodeBridgeMode(bridgeModeHash) {
@@ -65,10 +66,77 @@ const getUnit = bridgeMode => {
   return { unitHome, unitForeign }
 }
 
+const gasPriceWithinLimits = (gasPrice, limits) => {
+  if (!limits) {
+    return gasPrice
+  }
+  if (gasPrice < limits.MIN) {
+    return limits.MIN
+  } else if (gasPrice > limits.MAX) {
+    return limits.MAX
+  } else {
+    return gasPrice
+  }
+}
+
+const normalizeGasPrice = (oracleGasPrice, factor, limits = null) => {
+  let gasPrice = oracleGasPrice * factor
+  gasPrice = gasPriceWithinLimits(gasPrice, limits)
+  return toBN(toWei(gasPrice.toFixed(2).toString(), 'gwei'))
+}
+
+// fetchFn has to be supplied (instead of just url to oracle),
+// because this utility function is shared between Browser and Node,
+// we use built-in 'fetch' on browser side, and `node-fetch` package in Node.
+const gasPriceFromOracle = async (fetchFn, options = {}) => {
+  try {
+    const response = await fetchFn()
+    const json = await response.json()
+    const oracleGasPrice = json[options.speedType]
+
+    if (!oracleGasPrice) {
+      options.logger &&
+        options.logger.error &&
+        options.logger.error(`Response from Oracle didn't include gas price for ${options.speedType} type.`)
+      return null
+    }
+
+    const normalizedGasPrice = normalizeGasPrice(oracleGasPrice, options.factor, options.limits)
+
+    options.logger &&
+      options.logger.debug &&
+      options.logger.debug({ oracleGasPrice, normalizedGasPrice }, 'Gas price updated using the API')
+
+    return normalizedGasPrice
+  } catch (e) {
+    options.logger && options.logger.error && options.logger.error(`Gas Price API is not available. ${e.message}`)
+  }
+  return null
+}
+
+const gasPriceFromContract = async (bridgeContract, options = {}) => {
+  try {
+    const gasPrice = await bridgeContract.methods.gasPrice().call()
+    options.logger &&
+      options.logger.debug &&
+      options.logger.debug({ gasPrice }, 'Gas price updated using the contracts')
+    return gasPrice
+  } catch (e) {
+    options.logger &&
+      options.logger.error &&
+      options.logger.error(`There was a problem getting the gas price from the contract. ${e.message}`)
+  }
+  return null
+}
+
 module.exports = {
   decodeBridgeMode,
   decodeFeeManagerMode,
   getBridgeMode,
   getTokenType,
-  getUnit
+  getUnit,
+  normalizeGasPrice,
+  gasPriceFromOracle,
+  gasPriceFromContract,
+  gasPriceWithinLimits
 }

monitor/validators.js

@@ -2,7 +2,7 @@ require('dotenv').config()
 const Web3 = require('web3')
 const fetch = require('node-fetch')
 const logger = require('./logger')('validators')
-const { getBridgeABIs, BRIDGE_VALIDATORS_ABI } = require('../commons')
+const { getBridgeABIs, BRIDGE_VALIDATORS_ABI, gasPriceFromOracle } = require('../commons')
 const { getValidatorList } = require('./utils/validatorUtils')
 const { getBlockNumber } = require('./utils/contract')
 
@@ -33,40 +33,24 @@ const web3Home = new Web3(homeProvider)
 const foreignProvider = new Web3.providers.HttpProvider(FOREIGN_RPC_URL)
 const web3Foreign = new Web3(foreignProvider)
 
+const homeGasOracleOpts = {
+  speedType: HOME_GAS_PRICE_SPEED_TYPE,
+  factor: HOME_GAS_PRICE_FACTOR,
+  logger
+}
+
+const foreignGasOracleOpts = {
+  speedType: FOREIGN_GAS_PRICE_SPEED_TYPE,
+  factor: FOREIGN_GAS_PRICE_FACTOR,
+  logger
+}
+
 const asyncForEach = async (array, callback) => {
   for (let index = 0; index < array.length; index++) {
     await callback(array[index], index, array)
   }
 }
 
-function getGasPrices(url, type, factor, fallback) {
-  if (!url) {
-    return Web3Utils.toBN(fallback)
-  }
-  return fetchGasPrices(url, type, factor, fallback)
-}
-
-async function fetchGasPrices(url, type, factor, fallback) {
-  try {
-    const response = await fetch(url)
-    const json = await response.json()
-    logger.log('Fetched gasprice: ' + json[type])
-    const gasPrice = json[type]
-    if (!gasPrice) {
-      throw new Error(`Response from Oracle didn't include gas price for ${type} type.`)
-    }
-    return normalizeGasPrice(gasPrice, factor)
-  } catch (e) {
-    logger.error('Gas Price API is not available', e)
-    return Web3Utils.toBN(fallback)
-  }
-}
-
-function normalizeGasPrice(oracleGasPrice, factor) {
-  const gasPrice = oracleGasPrice * factor
-  return Web3Utils.toBN(Web3Utils.toWei(gasPrice.toFixed(2).toString(), 'gwei'))
-}
-
 async function main(bridgeMode) {
   const { HOME_ABI, FOREIGN_ABI } = getBridgeABIs(bridgeMode)
   const homeBridge = new web3Home.eth.Contract(HOME_ABI, HOME_BRIDGE_ADDRESS)
@@ -106,22 +90,16 @@ async function main(bridgeMode) {
   const homeVBalances = {}
 
   logger.debug('calling home getGasPrices')
-  const homeGasPrice = await getGasPrices(
+  const homeGasPrice =
-    HOME_GAS_PRICE_ORACLE_URL,
+    (await gasPriceFromOracle(() => fetch(HOME_GAS_PRICE_ORACLE_URL), homeGasOracleOpts)) ||
-    HOME_GAS_PRICE_SPEED_TYPE,
+    Web3Utils.toBN(HOME_GAS_PRICE_FALLBACK)
-    HOME_GAS_PRICE_FACTOR,
-    HOME_GAS_PRICE_FALLBACK
-  )
   const homeGasPriceGwei = Web3Utils.fromWei(homeGasPrice.toString(), 'gwei')
   const homeTxCost = homeGasPrice.mul(Web3Utils.toBN(HOME_GAS_LIMIT))
 
   logger.debug('calling foreign getGasPrices')
-  const foreignGasPrice = await getGasPrices(
+  const foreignGasPrice =
-    FOREIGN_GAS_PRICE_ORACLE_URL,
+    (await gasPriceFromOracle(() => fetch(FOREIGN_GAS_PRICE_ORACLE_URL), foreignGasOracleOpts)) ||
-    FOREIGN_GAS_PRICE_SPEED_TYPE,
+    Web3Utils.toBN(FOREIGN_GAS_PRICE_FALLBACK)
-    FOREIGN_GAS_PRICE_FACTOR,
-    FOREIGN_GAS_PRICE_FALLBACK
-  )
   const foreignGasPriceGwei = Web3Utils.fromWei(foreignGasPrice.toString(), 'gwei')
   const foreignTxCost = foreignGasPrice.mul(Web3Utils.toBN(FOREIGN_GAS_LIMIT))
 

oracle/src/services/gasPrice.js

@@ -1,6 +1,5 @@
 require('../../env')
 const fetch = require('node-fetch')
-const Web3Utils = require('web3-utils')
 const { web3Home, web3Foreign } = require('../services/web3')
 const { bridgeConfig } = require('../../config/base.config')
 const logger = require('../services/logger').child({
@@ -8,6 +7,7 @@ const logger = require('../services/logger').child({
 })
 const { setIntervalAndRun } = require('../utils/utils')
 const { DEFAULT_UPDATE_INTERVAL, GAS_PRICE_BOUNDARIES, DEFAULT_GAS_PRICE_FACTOR } = require('../utils/constants')
+const { gasPriceFromOracle, gasPriceFromContract } = require('../../../commons')
 
 const HomeABI = bridgeConfig.homeBridgeAbi
 const ForeignABI = bridgeConfig.foreignBridgeAbi
@@ -33,53 +33,18 @@ const foreignBridge = new web3Foreign.eth.Contract(ForeignABI, FOREIGN_BRIDGE_AD
 
 let cachedGasPrice = null
 
-function gasPriceWithinLimits(gasPrice) {
-  if (gasPrice < GAS_PRICE_BOUNDARIES.MIN) {
-    return GAS_PRICE_BOUNDARIES.MIN
-  } else if (gasPrice > GAS_PRICE_BOUNDARIES.MAX) {
-    return GAS_PRICE_BOUNDARIES.MAX
-  } else {
-    return gasPrice
-  }
-}
-
-function normalizeGasPrice(oracleGasPrice, factor) {
-  const gasPriceGwei = oracleGasPrice * factor
-  const gasPrice = gasPriceWithinLimits(gasPriceGwei)
-  return Web3Utils.toWei(gasPrice.toFixed(2).toString(), 'gwei')
-}
-
-async function fetchGasPriceFromOracle(oracleUrl, speedType, factor) {
-  const response = await fetch(oracleUrl)
-  const json = await response.json()
-  const oracleGasPrice = json[speedType]
-  if (!oracleGasPrice) {
-    throw new Error(`Response from Oracle didn't include gas price for ${speedType} type.`)
-  }
-
-  return normalizeGasPrice(oracleGasPrice, factor)
-}
-
-async function fetchGasPrice({ bridgeContract, oracleFn }) {
-  let gasPrice = null
-  try {
-    gasPrice = await oracleFn()
-    logger.debug({ gasPrice }, 'Gas price updated using the oracle')
-  } catch (e) {
-    logger.error(`Gas Price API is not available. ${e.message}`)
-
-    try {
-      gasPrice = await bridgeContract.methods.gasPrice().call()
-      logger.debug({ gasPrice }, 'Gas price updated using the contracts')
-    } catch (e) {
-      logger.error(`There was a problem getting the gas price from the contract. ${e.message}`)
-    }
-  }
-  return gasPrice
-}
-
 let fetchGasPriceInterval = null
 
+const fetchGasPrice = async (speedType, factor, bridgeContract, oracleFetchFn) => {
+  const contractOptions = { logger }
+  const oracleOptions = { speedType, factor, limits: GAS_PRICE_BOUNDARIES, logger }
+  cachedGasPrice =
+    (await gasPriceFromOracle(oracleFetchFn, oracleOptions)) ||
+    (await gasPriceFromContract(bridgeContract, contractOptions)) ||
+    cachedGasPrice
+  return cachedGasPrice
+}
+
 async function start(chainId) {
   clearInterval(fetchGasPriceInterval)
 
@@ -108,13 +73,10 @@ async function start(chainId) {
     throw new Error(`Unrecognized chainId '${chainId}'`)
   }
 
-  fetchGasPriceInterval = setIntervalAndRun(async () => {
+  fetchGasPriceInterval = setIntervalAndRun(
-    const gasPrice = await fetchGasPrice({
+    () => fetchGasPrice(speedType, factor, bridgeContract, () => fetch(oracleUrl)),
-      bridgeContract,
+    updateInterval
-      oracleFn: () => fetchGasPriceFromOracle(oracleUrl, speedType, factor)
+  )
-    })
-    cachedGasPrice = gasPrice || cachedGasPrice
-  }, updateInterval)
 }
 
 function getPrice() {
@@ -123,8 +85,6 @@ function getPrice() {
 
 module.exports = {
   start,
-  fetchGasPrice,
   getPrice,
-  gasPriceWithinLimits,
+  fetchGasPrice
-  normalizeGasPrice
 }

oracle/test/gasPrice.test.js

@@ -1,80 +1,9 @@
 const sinon = require('sinon')
 const { expect } = require('chai')
 const proxyquire = require('proxyquire').noPreserveCache()
-const Web3Utils = require('web3-utils')
+const { DEFAULT_UPDATE_INTERVAL } = require('../src/utils/constants')
-const { fetchGasPrice, gasPriceWithinLimits, normalizeGasPrice } = require('../src/services/gasPrice')
-const { DEFAULT_UPDATE_INTERVAL, GAS_PRICE_BOUNDARIES } = require('../src/utils/constants')
 
 describe('gasPrice', () => {
-  describe('fetchGasPrice', () => {
-    beforeEach(() => {
-      sinon.stub(console, 'error')
-    })
-    afterEach(() => {
-      console.error.restore()
-    })
-
-    it('should fetch the gas price from the oracle by default', async () => {
-      // given
-      const oracleFnMock = () => Promise.resolve('1')
-      const bridgeContractMock = {
-        methods: {
-          gasPrice: {
-            call: sinon.stub().returns(Promise.resolve('2'))
-          }
-        }
-      }
-
-      // when
-      const gasPrice = await fetchGasPrice({
-        bridgeContract: bridgeContractMock,
-        oracleFn: oracleFnMock
-      })
-
-      // then
-      expect(gasPrice).to.equal('1')
-    })
-    it('should fetch the gas price from the contract if the oracle fails', async () => {
-      // given
-      const oracleFnMock = () => Promise.reject(new Error('oracle failed'))
-      const bridgeContractMock = {
-        methods: {
-          gasPrice: sinon.stub().returns({
-            call: sinon.stub().returns(Promise.resolve('2'))
-          })
-        }
-      }
-
-      // when
-      const gasPrice = await fetchGasPrice({
-        bridgeContract: bridgeContractMock,
-        oracleFn: oracleFnMock
-      })
-
-      // then
-      expect(gasPrice).to.equal('2')
-    })
-    it('should return null if both the oracle and the contract fail', async () => {
-      // given
-      const oracleFnMock = () => Promise.reject(new Error('oracle failed'))
-      const bridgeContractMock = {
-        methods: {
-          gasPrice: sinon.stub().returns({
-            call: sinon.stub().returns(Promise.reject(new Error('contract failed')))
-          })
-        }
-      }
-
-      // when
-      const gasPrice = await fetchGasPrice({
-        bridgeContract: bridgeContractMock,
-        oracleFn: oracleFnMock
-      })
-
-      // then
-      expect(gasPrice).to.equal(null)
-    })
-  })
   describe('start', () => {
     const utils = { setIntervalAndRun: sinon.spy() }
     beforeEach(() => {
@@ -131,101 +60,104 @@ describe('gasPrice', () => {
       expect(utils.setIntervalAndRun.args[0][1]).to.equal(DEFAULT_UPDATE_INTERVAL)
     })
   })
-  describe('gasPriceWithinLimits', () => {
+
-    it('should return gas price if gas price is between boundaries', () => {
+  describe('fetching gas price', () => {
+    const utils = { setIntervalAndRun: () => {} }
+
+    it('should fall back to default if contract and oracle/supplier are not working', async () => {
       // given
-      const minGasPrice = 1
+      process.env.HOME_GAS_PRICE_FALLBACK = '101000000000'
-      const middleGasPrice = 10
+      const gasPrice = proxyquire('../src/services/gasPrice', { '../utils/utils': utils })
-      const maxGasPrice = 250
+      await gasPrice.start('home')
 
       // when
-      const minGasPriceWithinLimits = gasPriceWithinLimits(minGasPrice)
+      await gasPrice.fetchGasPrice('standard', 1, null, null)
-      const middleGasPriceWithinLimits = gasPriceWithinLimits(middleGasPrice)
-      const maxGasPriceWithinLimits = gasPriceWithinLimits(maxGasPrice)
 
       // then
-      expect(minGasPriceWithinLimits).to.equal(minGasPrice)
+      expect(gasPrice.getPrice()).to.equal('101000000000')
-      expect(middleGasPriceWithinLimits).to.equal(middleGasPrice)
-      expect(maxGasPriceWithinLimits).to.equal(maxGasPrice)
     })
-    it('should return min limit if gas price is below min boundary', () => {
-      // Given
-      const initialGasPrice = 0.5
 
-      // When
+    it('should fetch gas from oracle/supplier', async () => {
-      const gasPrice = gasPriceWithinLimits(initialGasPrice)
+      // given
+      process.env.HOME_GAS_PRICE_FALLBACK = '101000000000'
+      const gasPrice = proxyquire('../src/services/gasPrice', { '../utils/utils': utils })
+      await gasPrice.start('home')
 
-      // Then
+      const oracleFetchFn = () => ({
-      expect(gasPrice).to.equal(GAS_PRICE_BOUNDARIES.MIN)
+        json: () => ({
+          standard: '103'
+        })
+      })
+
+      // when
+      await gasPrice.fetchGasPrice('standard', 1, null, oracleFetchFn)
+
+      // then
+      expect(gasPrice.getPrice().toString()).to.equal('103000000000')
     })
-    it('should return max limit if gas price is above max boundary', () => {
-      // Given
-      const initialGasPrice = 260
 
-      // When
+    it('should fetch gas from contract', async () => {
-      const gasPrice = gasPriceWithinLimits(initialGasPrice)
+      // given
+      process.env.HOME_GAS_PRICE_FALLBACK = '101000000000'
+      const gasPrice = proxyquire('../src/services/gasPrice', { '../utils/utils': utils })
+      await gasPrice.start('home')
 
-      // Then
+      const bridgeContractMock = {
-      expect(gasPrice).to.equal(GAS_PRICE_BOUNDARIES.MAX)
+        methods: {
+          gasPrice: sinon.stub().returns({
+            call: sinon.stub().returns(Promise.resolve('102000000000'))
+          })
+        }
+      }
+
+      // when
+      await gasPrice.fetchGasPrice('standard', 1, bridgeContractMock, null)
+
+      // then
+      expect(gasPrice.getPrice().toString()).to.equal('102000000000')
     })
-  })
-  describe('normalizeGasPrice', () => {
-    it('should work with oracle gas price in gwei', () => {
-      // Given
-      const oracleGasPrice = 20
-      const factor = 1
 
-      // When
+    it('should fetch the gas price from the oracle first', async () => {
-      const result = normalizeGasPrice(oracleGasPrice, factor)
+      // given
+      process.env.HOME_GAS_PRICE_FALLBACK = '101000000000'
+      const gasPrice = proxyquire('../src/services/gasPrice', { '../utils/utils': utils })
+      await gasPrice.start('home')
 
-      // Then
+      const bridgeContractMock = {
-      expect(result).to.equal('20000000000')
+        methods: {
+          gasPrice: sinon.stub().returns({
+            call: sinon.stub().returns(Promise.resolve('102000000000'))
+          })
+        }
+      }
+
+      const oracleFetchFn = () => ({
+        json: () => ({
+          standard: '103'
+        })
+      })
+
+      // when
+      await gasPrice.fetchGasPrice('standard', 1, bridgeContractMock, oracleFetchFn)
+
+      // then
+      expect(gasPrice.getPrice().toString()).to.equal('103000000000')
     })
-    it('should work with oracle gas price not in gwei', () => {
-      // Given
-      const oracleGasPrice = 200
-      const factor = 0.1
 
-      // When
+    it('log errors using the logger', async () => {
-      const result = normalizeGasPrice(oracleGasPrice, factor)
+      // given
+      const fakeLogger = { error: sinon.spy() }
+      const gasPrice = proxyquire('../src/services/gasPrice', {
+        '../utils/utils': utils,
+        '../services/logger': { child: () => fakeLogger }
+      })
+      await gasPrice.start('home')
 
-      // Then
+      // when
-      expect(result).to.equal('20000000000')
+      await gasPrice.fetchGasPrice('standard', 1, null, null)
-    })
-    it('should increase gas price value from oracle', () => {
-      // Given
-      const oracleGasPrice = 20
-      const factor = 1.5
 
-      // When
+      // then
-      const result = normalizeGasPrice(oracleGasPrice, factor)
+      expect(fakeLogger.error.calledTwice).to.equal(true) // two errors
-
-      // Then
-      expect(result).to.equal('30000000000')
-    })
-    it('should respect gas price max limit', () => {
-      // Given
-      const oracleGasPrice = 200
-      const factor = 4
-      const maxInWei = Web3Utils.toWei(GAS_PRICE_BOUNDARIES.MAX.toString(), 'gwei')
-
-      // When
-      const result = normalizeGasPrice(oracleGasPrice, factor)
-
-      // Then
-      expect(result).to.equal(maxInWei)
-    })
-    it('should respect gas price min limit', () => {
-      // Given
-      const oracleGasPrice = 1
-      const factor = 0.01
-      const minInWei = Web3Utils.toWei(GAS_PRICE_BOUNDARIES.MIN.toString(), 'gwei')
-
-      // When
-      const result = normalizeGasPrice(oracleGasPrice, factor)
-
-      // Then
-      expect(result).to.equal(minInWei)
     })
   })
 })

ui/src/stores/GasPriceStore.js

@@ -1,6 +1,6 @@
 import { observable, computed } from 'mobx'
 import { toHex } from 'web3-utils'
-import { fetchGasPrice, fetchGasPriceFromOracle } from './utils/gas'
+import { gasPriceFromOracle } from '../../../commons'
 
 const HOME_GAS_PRICE_FALLBACK = process.env.REACT_APP_HOME_GAS_PRICE_FALLBACK
 const HOME_GAS_PRICE_ORACLE_URL = process.env.REACT_APP_HOME_GAS_PRICE_ORACLE_URL
@@ -50,11 +50,9 @@ class GasPriceStore {
       this.factor = Number(FOREIGN_GAS_PRICE_FACTOR) || DEFAULT_GAS_PRICE_FACTOR
     }
 
-    const newGasPrice = await fetchGasPrice({
+    const oracleOptions = { speedType: this.speedType, factor: this.factor, logger: console }
-      oracleFn: () => fetchGasPriceFromOracle(this.oracleUrl, this.speedType, this.factor)
+    this.gasPrice = (await gasPriceFromOracle(() => fetch(this.oracleUrl), oracleOptions)) || this.gasPrice
-    })
 
-    this.gasPrice = newGasPrice || this.gasPrice
     setTimeout(() => this.updateGasPrice(), this.updateInterval)
   }
 

ui/src/stores/utils/__tests__/gas.test.js

@@ -1,37 +0,0 @@
-import { normalizeGasPrice } from '../gas'
-
-describe('normalizeGasPrice', () => {
-  it('should work with oracle gas price in gwei', () => {
-    // Given
-    const oracleGasPrice = 30
-    const factor = 1
-
-    // When
-    const result = normalizeGasPrice(oracleGasPrice, factor)
-
-    // Then
-    expect(result).toEqual('30000000000')
-  })
-  it('should work with oracle gas price not in gwei', () => {
-    // Given
-    const oracleGasPrice = 300
-    const factor = 0.1
-
-    // When
-    const result = normalizeGasPrice(oracleGasPrice, factor)
-
-    // Then
-    expect(result).toEqual('30000000000')
-  })
-  it('should increase gas price value from oracle', () => {
-    // Given
-    const oracleGasPrice = 20
-    const factor = 1.5
-
-    // When
-    const result = normalizeGasPrice(oracleGasPrice, factor)
-
-    // Then
-    expect(result).toEqual('30000000000')
-  })
-})

ui/src/stores/utils/gas.js

@@ -1,31 +0,0 @@
-const { toWei } = require('web3-utils')
-
-export async function fetchGasPrice({ oracleFn }) {
-  let gasPrice = null
-  try {
-    gasPrice = await oracleFn()
-  } catch (e) {
-    if (!e.message.includes('Gas Price Oracle url not defined')) {
-      console.error(`Gas Price API is not available. ${e.message}`)
-    }
-  }
-  return gasPrice
-}
-
-export async function fetchGasPriceFromOracle(oracleUrl, speedType, factor) {
-  if (!oracleUrl) {
-    throw new Error(`Gas Price Oracle url not defined`)
-  }
-  const response = await fetch(oracleUrl)
-  const json = await response.json()
-  const gasPrice = json[speedType]
-  if (!gasPrice) {
-    throw new Error(`Response from Oracle didn't include gas price for ${speedType} type.`)
-  }
-  return normalizeGasPrice(gasPrice, factor)
-}
-
-export function normalizeGasPrice(oracleGasPrice, factor) {
-  const gasPrice = oracleGasPrice * factor
-  return toWei(gasPrice.toFixed(2).toString(), 'gwei')
-}