Merge pull request #3982 from MetaMask/i3981-contract-rates
Fetch token prices based on contract addressfeature/default_network_editable
Dan Finlay
7 years ago
committed by
GitHub
commit
e4eb69dcc2
@ -0,0 +1,77 @@ |
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const ObservableStore = require('obs-store') |
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// By default, poll every 3 minutes
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const DEFAULT_INTERVAL = 180 * 1000 |
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/** |
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* A controller that polls for token exchange |
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* rates based on a user's current token list |
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*/ |
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class TokenRatesController { |
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/** |
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* Creates a TokenRatesController |
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* |
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* @param {Object} [config] - Options to configure controller |
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*/ |
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constructor ({ interval = DEFAULT_INTERVAL, preferences } = {}) { |
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this.store = new ObservableStore() |
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this.preferences = preferences |
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this.interval = interval |
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} |
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/** |
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* Updates exchange rates for all tokens |
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*/ |
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async updateExchangeRates () { |
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if (!this.isActive) { return } |
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const contractExchangeRates = {} |
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for (const i in this._tokens) { |
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const address = this._tokens[i].address |
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contractExchangeRates[address] = await this.fetchExchangeRate(address) |
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} |
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this.store.putState({ contractExchangeRates }) |
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} |
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/** |
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* Fetches a token exchange rate by address |
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* |
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* @param {String} address - Token contract address |
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*/ |
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async fetchExchangeRate (address) { |
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try { |
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const response = await fetch(`https://exchanges.balanc3.net/prices?from=${address}&to=ETH&autoConversion=false&summaryOnly=true`) |
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const json = await response.json() |
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return json && json.length ? json[0].averagePrice : 0 |
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} catch (error) { } |
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} |
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/** |
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* @type {Number} - Interval used to poll for exchange rates |
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*/ |
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set interval (interval) { |
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this._handle && clearInterval(this._handle) |
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if (!interval) { return } |
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this._handle = setInterval(() => { this.updateExchangeRates() }, interval) |
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} |
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/** |
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* @type {Object} - Preferences controller instance |
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*/ |
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set preferences (preferences) { |
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this._preferences && this._preferences.unsubscribe() |
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if (!preferences) { return } |
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this._preferences = preferences |
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this.tokens = preferences.getState().tokens |
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preferences.subscribe(({ tokens = [] }) => { this.tokens = tokens }) |
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} |
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/** |
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* @type {Array} - Array of token objects with contract addresses |
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*/ |
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set tokens (tokens) { |
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this._tokens = tokens |
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this.updateExchangeRates() |
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} |
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} |
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module.exports = TokenRatesController |
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@ -0,0 +1,29 @@ |
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const assert = require('assert') |
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const sinon = require('sinon') |
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const TokenRatesController = require('../../app/scripts/controllers/token-rates') |
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const ObservableStore = require('obs-store') |
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describe('TokenRatesController', () => { |
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it('should listen for preferences store updates', () => { |
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const preferences = new ObservableStore({ tokens: [] }) |
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const controller = new TokenRatesController({ preferences }) |
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preferences.putState({ tokens: ['foo'] }) |
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assert.deepEqual(controller._tokens, ['foo']) |
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}) |
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it('should poll on correct interval', async () => { |
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const stub = sinon.stub(global, 'setInterval') |
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new TokenRatesController({ interval: 1337 }) // eslint-disable-line no-new
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assert.strictEqual(stub.getCall(0).args[1], 1337) |
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stub.restore() |
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}) |
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it('should fetch each token rate based on address', async () => { |
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const controller = new TokenRatesController() |
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controller.isActive = true |
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controller.fetchExchangeRate = address => address |
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controller.tokens = [{ address: 'foo' }, { address: 'bar' }] |
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await controller.updateExchangeRates() |
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assert.deepEqual(controller.store.getState().contractExchangeRates, { foo: 'foo', bar: 'bar' }) |
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}) |
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}) |
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