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metamask-extension/app/scripts/controllers/token-rates.js
Mark Stacey 5ee1291662
Prevent accidental use of globals (#8340)
Previously all browser globals were allowed to be used anywhere by
ESLint because we had set the `env` property to `browser` in the ESLint
config. This has made it easy to accidentally use browser globals
(e.g. #8338), so it has been removed. Instead we now have a short list
of allowed globals.

All browser globals are now accessed as properties on `window`.

Unfortunately this change resulted in a few different confusing unit
test errors, as some of our unit tests setup assumed that a particular
global would be used via `window` or `global`. In particular,
`window.fetch` didn't work correctly because it wasn't patched by the
AbortController polyfill (only `global.fetch` was being patched).
The `jsdom-global` package we were using complicated matters by setting
all of the JSDOM `window` properties directly on `global`, overwriting
the `AbortController` for example.

The `helpers.js` test setup module has been simplified somewhat by
removing `jsdom-global` and constructing the JSDOM instance manually.
The JSDOM window is set on `window`, and a few properties are set on
`global` as well as needed by various dependencies. `node-fetch` and
the AbortController polyfill/patch now work as expected as well,
though `fetch` is only available on `window` now.
2020-04-15 14:23:27 -03:00

91 lines
2.5 KiB
JavaScript

import ObservableStore from 'obs-store'
import log from 'loglevel'
import { normalize as normalizeAddress } from 'eth-sig-util'
import ethUtil from 'ethereumjs-util'
// By default, poll every 3 minutes
const DEFAULT_INTERVAL = 180 * 1000
/**
* A controller that polls for token exchange
* rates based on a user's current token list
*/
class TokenRatesController {
/**
* Creates a TokenRatesController
*
* @param {Object} [config] - Options to configure controller
*/
constructor ({ interval = DEFAULT_INTERVAL, currency, preferences } = {}) {
this.store = new ObservableStore()
this.currency = currency
this.preferences = preferences
this.interval = interval
}
/**
* Updates exchange rates for all tokens
*/
async updateExchangeRates () {
if (!this.isActive) {
return
}
const contractExchangeRates = {}
const nativeCurrency = this.currency ? this.currency.state.nativeCurrency.toLowerCase() : 'eth'
const pairs = this._tokens.map((token) => token.address).join(',')
const query = `contract_addresses=${pairs}&vs_currencies=${nativeCurrency}`
if (this._tokens.length > 0) {
try {
const response = await window.fetch(`https://api.coingecko.com/api/v3/simple/token_price/ethereum?${query}`)
const prices = await response.json()
this._tokens.forEach((token) => {
const price = prices[token.address.toLowerCase()] || prices[ethUtil.toChecksumAddress(token.address)]
contractExchangeRates[normalizeAddress(token.address)] = price ? price[nativeCurrency] : 0
})
} catch (error) {
log.warn(`MetaMask - TokenRatesController exchange rate fetch failed.`, error)
}
}
this.store.putState({ contractExchangeRates })
}
/**
* @type {Number}
*/
set interval (interval) {
this._handle && clearInterval(this._handle)
if (!interval) {
return
}
this._handle = setInterval(() => {
this.updateExchangeRates()
}, interval)
}
/**
* @type {Object}
*/
set preferences (preferences) {
this._preferences && this._preferences.unsubscribe()
if (!preferences) {
return
}
this._preferences = preferences
this.tokens = preferences.getState().tokens
preferences.subscribe(({ tokens = [] }) => {
this.tokens = tokens
})
}
/**
* @type {Array}
*/
set tokens (tokens) {
this._tokens = tokens
this.updateExchangeRates()
}
}
export default TokenRatesController