Merge branch 'uat' into newmaster

1 files changed, 221 insertions, 0 deletions

diff --git a/ui/app/conversion-util.js b/ui/app/conversion-util.js
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+/* Currency Conversion Utility
+* This utility function can be used for converting currency related values within metamask.
+* The caller should be able to pass it a value, along with information about the value's
+* numeric base, denomination and currency, and the desired numeric base, denomination and
+* currency. It should return a single value.
+*
+* @param {(number | string | BN)} value The value to convert.
+* @param {Object} [options] Options to specify details of the conversion
+* @param {string} [options.fromCurrency = 'ETH' | 'USD'] The currency of the passed value
+* @param {string} [options.toCurrency = 'ETH' | 'USD'] The desired currency of the result
+* @param {string} [options.fromNumericBase = 'hex' | 'dec' | 'BN'] The numeric basic of the passed value.
+* @param {string} [options.toNumericBase = 'hex' | 'dec' | 'BN'] The desired numeric basic of the result.
+* @param {string} [options.fromDenomination = 'WEI'] The denomination of the passed value
+* @param {number} [options.numberOfDecimals] The desired number of in the result
+* @param {number} [options.conversionRate] The rate to use to make the fromCurrency -> toCurrency conversion
+* @returns {(number | string | BN)}
+*
+* The utility passes value along with the options as a single object to the `converter` function.
+* `converter` uses Ramda.js to apply a composition of conditional setters to the `value` property, depending
+* on the accompanying options. Some of these conditional setters are selected via key-value maps, where
+* the keys are specified in the options parameters and the values are setter functions.
+*/
+
+const BigNumber = require('bignumber.js')
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+const R = require('ramda')
+const { stripHexPrefix } = require('ethereumjs-util')
+
+BigNumber.config({
+  ROUNDING_MODE: BigNumber.ROUND_HALF_DOWN,
+})
+
+// Big Number Constants
+const BIG_NUMBER_WEI_MULTIPLIER = new BigNumber('1000000000000000000')
+const BIG_NUMBER_GWEI_MULTIPLIER = new BigNumber('1000000000')
+
+// Individual Setters
+const convert = R.invoker(1, 'times')
+const round = R.invoker(2, 'round')(R.__, BigNumber.ROUND_HALF_DOWN)
+const invertConversionRate = conversionRate => () => new BigNumber(1.0).div(conversionRate)
+const decToBigNumberViaString = n => R.pipe(String, toBigNumber['dec'])
+
+// Setter Maps
+const toBigNumber = {
+  hex: n => new BigNumber(stripHexPrefix(n), 16),
+  dec: n => new BigNumber(n, 10),
+  BN: n => new BigNumber(n.toString(16), 16),
+}
+const toNormalizedDenomination = {
+  WEI: bigNumber => bigNumber.div(BIG_NUMBER_WEI_MULTIPLIER),
+  GWEI: bigNumber => bigNumber.div(BIG_NUMBER_GWEI_MULTIPLIER),
+}
+const toSpecifiedDenomination = {
+  WEI: bigNumber => bigNumber.times(BIG_NUMBER_WEI_MULTIPLIER).round(),
+  GWEI: bigNumber => bigNumber.times(BIG_NUMBER_GWEI_MULTIPLIER).round(9),
+}
+const baseChange = {
+  hex: n => n.toString(16),
+  dec: n => Number(n).toString(10),
+  BN: n => new BN(n.toString(16)),
+}
+
+// Predicates
+const fromAndToCurrencyPropsNotEqual = R.compose(
+  R.not,
+  R.eqBy(R.__, 'fromCurrency', 'toCurrency'),
+  R.flip(R.prop)
+)
+
+// Lens
+const valuePropertyLens = R.over(R.lensProp('value'))
+const conversionRateLens = R.over(R.lensProp('conversionRate'))
+
+// conditional conversionRate setting wrapper
+const whenPredSetCRWithPropAndSetter = (pred, prop, setter) => R.when(
+  pred,
+  R.converge(
+    conversionRateLens,
+    [R.pipe(R.prop(prop), setter), R.identity]
+  )
+)
+
+// conditional 'value' setting wrappers
+const whenPredSetWithPropAndSetter = (pred, prop, setter) => R.when(
+  pred,
+  R.converge(
+    valuePropertyLens,
+    [R.pipe(R.prop(prop), setter), R.identity]
+  )
+)
+const whenPropApplySetterMap = (prop, setterMap) => whenPredSetWithPropAndSetter(
+  R.prop(prop),
+  prop,
+  R.prop(R.__, setterMap)
+)
+
+// Conversion utility function
+const converter = R.pipe(
+  whenPredSetCRWithPropAndSetter(R.prop('conversionRate'), 'conversionRate', decToBigNumberViaString),
+  whenPredSetCRWithPropAndSetter(R.prop('invertConversionRate'), 'conversionRate', invertConversionRate),
+  whenPropApplySetterMap('fromNumericBase', toBigNumber),
+  whenPropApplySetterMap('fromDenomination', toNormalizedDenomination),
+  whenPredSetWithPropAndSetter(fromAndToCurrencyPropsNotEqual, 'conversionRate', convert),
+  whenPropApplySetterMap('toDenomination', toSpecifiedDenomination),
+  whenPredSetWithPropAndSetter(R.prop('numberOfDecimals'), 'numberOfDecimals', round),
+  whenPropApplySetterMap('toNumericBase', baseChange),
+  R.view(R.lensProp('value'))
+)
+
+const conversionUtil = (value, {
+  fromCurrency = null,
+  toCurrency = fromCurrency,
+  fromNumericBase,
+  toNumericBase,
+  fromDenomination,
+  toDenomination,
+  numberOfDecimals,
+  conversionRate,
+  invertConversionRate,
+}) => converter({
+  fromCurrency,
+  toCurrency,
+  fromNumericBase,
+  toNumericBase,
+  fromDenomination,
+  toDenomination,
+  numberOfDecimals,
+  conversionRate,
+  invertConversionRate,
+  value: value || '0',
+})
+
+const addCurrencies = (a, b, options = {}) => {
+  const {
+    aBase,
+    bBase,
+    ...conversionOptions
+  } = options
+  const value = (new BigNumber(a, aBase)).add(b, bBase)
+
+  return converter({
+    value,
+    ...conversionOptions,
+  })
+}
+
+const subtractCurrencies = (a, b, options = {}) => {
+  const {
+    aBase,
+    bBase,
+    ...conversionOptions
+  } = options
+  const value = (new BigNumber(a, aBase)).minus(b, bBase)
+
+  return converter({
+    value,
+    ...conversionOptions,
+  })
+}
+
+const multiplyCurrencies = (a, b, options = {}) => {
+  const {
+    multiplicandBase,
+    multiplierBase,
+    ...conversionOptions
+  } = options
+
+  const bigNumberA = new BigNumber(String(a), multiplicandBase)
+  const bigNumberB = new BigNumber(String(b), multiplierBase)
+
+  const value = bigNumberA.times(bigNumberB)
+
+  return converter({
+    value,
+    ...conversionOptions,
+  })
+}
+
+const conversionGreaterThan = (
+  { ...firstProps },
+  { ...secondProps },
+) => {
+  const firstValue = converter({ ...firstProps })
+  const secondValue = converter({ ...secondProps })
+
+  return firstValue.gt(secondValue)
+}
+
+const conversionGTE = (
+  { ...firstProps },
+  { ...secondProps },
+) => {
+  const firstValue = converter({ ...firstProps })
+  const secondValue = converter({ ...secondProps })
+  return firstValue.greaterThanOrEqualTo(secondValue)
+}
+
+const conversionLTE = (
+  { ...firstProps },
+  { ...secondProps },
+) => {
+  const firstValue = converter({ ...firstProps })
+  const secondValue = converter({ ...secondProps })
+  return firstValue.lessThanOrEqualTo(secondValue)
+}
+
+const toNegative = (n, options = {}) => {
+  return multiplyCurrencies(n, -1, options)
+}
+
+module.exports = {
+  conversionUtil,
+  addCurrencies,
+  multiplyCurrencies,
+  conversionGreaterThan,
+  conversionGTE,
+  conversionLTE,
+  toNegative,
+  subtractCurrencies,
+}