feature/default_network_editable
Dan
7 years ago
committed by
Chi Kei Chan
parent
492507aa94
commit
080890a46e
@ -1,49 +1,108 @@ |
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const { |
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numericBalance, |
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parseBalance, |
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formatBalance, |
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normalizeToWei, |
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valueTable, |
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} = require('./util') |
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const hexToBn = require('../../app/scripts/lib/hex-to-bn') |
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const { BN } = require('ethereumjs-util') |
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const GWEI_MULTIPLIER = normalizeToWei(hexToBn(valueTable.gwei.toString(16)), 'gwei'); |
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/* Currency Conversion Utility |
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* This utility function can be used for converting currency related values within metamask. |
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* The caller should be able to pass it a value, along with information about the value's |
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* numeric base, denomination and currency, and the desired numeric base, denomination and |
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* currency. It should return a single value. |
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* |
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* @param {(number | string | BN)} value The value to convert. |
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* @param {Object} [options] Options to specify details of the conversion |
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* @param {string} [options.fromCurrency = 'ETH' | 'USD'] The currency of the passed value |
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* @param {string} [options.toCurrency = 'ETH' | 'USD'] The desired currency of the result |
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* @param {string} [options.fromNumericBase = 'hex' | 'dec' | 'BN'] The numeric basic of the passed value. |
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* @param {string} [options.toNumericBase = 'hex' | 'dec' | 'BN'] The desired numeric basic of the result. |
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* @param {string} [options.fromDenomination = 'WEI'] The denomination of the passed value |
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* @param {number} [options.numberOfDecimals] The desired number of in the result |
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* @param {number} [options.conversionRate] The rate to use to make the fromCurrency -> toCurrency conversion |
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* @returns {(number | string | BN)} |
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* |
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* The utility passes value along with the options as a single object to the `converter` function. |
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* `converter` uses Ramda.js to apply a composition of conditional setters to the `value` property, depending |
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* on the accompanying options. Some of these conditional setters are selected via key-value maps, where |
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* the keys are specified in the options parameters and the values are setter functions. |
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*/ |
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|
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const BigNumber = require('bignumber.js') |
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const R = require('ramda') |
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const { stripHexPrefix } = require('ethereumjs-util') |
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|
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BigNumber.config({ |
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ROUNDING_MODE: BigNumber.ROUND_HALF_DOWN, |
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}) |
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|
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// Big Number Constants
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const BIG_NUMBER_WEI_MULTIPLIER = new BigNumber('1000000000000000000') |
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|
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// Individual Setters
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const convert = R.invoker(1, 'times') |
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const round = R.invoker(2, 'toFormat')(R.__, BigNumber.ROUND_DOWN) |
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|
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// Setter Maps
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const toBigNumber = { |
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hex: n => new BigNumber(stripHexPrefix(n), 16), |
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dec: n => new BigNumber(n, 10), |
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BN: n => new BigNumber(n.toString(16), 16), |
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} |
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const toNormalizedDenomination = { |
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WEI: bigNumber => bigNumber.div(BIG_NUMBER_WEI_MULTIPLIER) |
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} |
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const baseChange = { |
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hex: n => n.toString(16), |
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dec: n => n.toString(10), |
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BN: n => new BN(n.toString(16)), |
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} |
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|
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// Predicates
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const fromAndToCurrencyPropsNotEqual = R.compose( |
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R.not, |
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R.eqBy(R.__, 'fromCurrency', 'toCurrency'), |
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R.flip(R.prop) |
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) |
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|
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// Lens
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const valuePropertyLense = R.over(R.lensProp('value')) |
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|
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// conditional 'value' setting wrappers
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const whenPredSetWithPropAndSetter = (pred, prop, setter) => R.when( |
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pred, |
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R.converge( |
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valuePropertyLense, |
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[R.pipe(R.prop(prop), setter), R.identity] |
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) |
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) |
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const whenPropApplySetterMap = (prop, setterMap) => whenPredSetWithPropAndSetter( |
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R.prop(prop), |
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prop, |
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R.prop(R.__, setterMap) |
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) |
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|
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// Conversion utility function
|
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const converter = R.pipe( |
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whenPropApplySetterMap('fromNumericBase', toBigNumber), |
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whenPropApplySetterMap('fromDenomination', toNormalizedDenomination), |
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whenPredSetWithPropAndSetter(fromAndToCurrencyPropsNotEqual, 'conversionRate', convert), |
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whenPredSetWithPropAndSetter(R.prop('numberOfDecimals'), 'numberOfDecimals', round), |
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whenPropApplySetterMap('toNumericBase', baseChange), |
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R.view(R.lensProp('value')) |
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); |
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|
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const conversionUtil = (value, { |
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fromCurrency = null, |
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toCurrency = fromCurrency, |
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fromNumericBase, |
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toNumericBase, |
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fromDenomination, |
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numberOfDecimals, |
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conversionRate, |
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}) => converter({ |
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fromCurrency, |
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toCurrency, |
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fromFormat, |
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toFormat, |
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precision = 2, |
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fromNumericBase, |
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toNumericBase, |
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fromDenomination, |
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numberOfDecimals, |
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conversionRate, |
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}) => { |
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let result; |
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|
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if (fromFormat === 'BN') { |
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if (fromCurrency !== 'GWEI') { |
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result = normalizeToWei(value, 'gwei') |
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} |
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else { |
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result = value |
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} |
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|
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result = result.toString(16) |
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result = formatBalance(result, 9) |
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result = result.split(' ') |
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result = Number(result[0]) * 1000000000 |
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} |
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|
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if (fromCurrency === 'GWEI') { |
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result = result / 1000000000 |
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} |
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|
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if (toCurrency === 'USD') { |
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result = result * conversionRate |
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result = result.toFixed(precision) |
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} |
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return result |
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}; |
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value, |
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}); |
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|
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module.exports = { |
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conversionUtil, |
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|
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