CurrencyController can be configured to always fetch usd rate

src/assets/CurrencyRateController.ts

@@ -11,11 +11,13 @@ const { Mutex } = require('await-semaphore');
  * @property currentCurrency - Currently-active ISO 4217 currency code
  * @property interval - Polling interval used to fetch new currency rate
  * @property nativeCurrency - Symbol for the base asset used for conversion
+ * @property includeUSDRate - Whether to include the usd rate in addition to the currentCurrency
  */
 export interface CurrencyRateConfig extends BaseConfig {
  currentCurrency: string;
  interval: number;
  nativeCurrency: string;
+ includeUSDRate?: boolean;
 }
 
 /**
@@ -27,19 +29,24 @@ export interface CurrencyRateConfig extends BaseConfig {
  * @property conversionRate - Conversion rate from current base asset to the current currency
  * @property currentCurrency - Currently-active ISO 4217 currency code
  * @property nativeCurrency - Symbol for the base asset used for conversion
+ * @property usdConversionRate - Conversion rate from usd to the current currency
  */
 export interface CurrencyRateState extends BaseState {
  conversionDate: number;
  conversionRate: number;
  currentCurrency: string;
  nativeCurrency: string;
+ usdConversionRate?: number;
 }
 
 /**
  * Controller that passively polls on a set interval for an exchange rate from the current base
  * asset to the current currency
  */
 export class CurrencyRateController extends BaseController<CurrencyRateConfig, CurrencyRateState> {
+ /* Optional config to include conversion to usd in all price url fetches and on state */
+ includeUSDRate?: boolean;
+
  private activeCurrency = '';
 
  private activeNativeCurrency = '';
@@ -52,10 +59,11 @@ export class CurrencyRateController extends BaseController<CurrencyRateConfig, C
  return state && state.currentCurrency ? state.currentCurrency : 'usd';
  }
 
- private getPricingURL(currentCurrency: string, nativeCurrency: string) {
+ private getPricingURL(currentCurrency: string, nativeCurrency: string, includeUSDRate?: boolean) {
  return (
  `https://min-api.cryptocompare.com/data/price?fsym=` +
- `${nativeCurrency.toUpperCase()}&tsyms=${currentCurrency.toUpperCase()}`
+ `${nativeCurrency.toUpperCase()}&tsyms=${currentCurrency.toUpperCase()}` +
+ `${includeUSDRate && currentCurrency.toUpperCase() !== 'USD' ? ',USD' : ''}`
  );
  }
 
@@ -77,12 +85,14 @@ export class CurrencyRateController extends BaseController<CurrencyRateConfig, C
  disabled: true,
  interval: 180000,
  nativeCurrency: 'ETH',
+ includeUSDRate: false,
  };
  this.defaultState = {
  conversionDate: 0,
  conversionRate: 0,
  currentCurrency: this.defaultConfig.currentCurrency,
  nativeCurrency: this.defaultConfig.nativeCurrency,
+ usdConversionRate: 0,
  };
  this.initialize();
  this.configure({ disabled: false }, false, false);
@@ -128,21 +138,26 @@ export class CurrencyRateController extends BaseController<CurrencyRateConfig, C
  *
  * @param currency - ISO 4217 currency code
  * @param nativeCurrency - Symbol for base asset
+ * @param includeUSDRate - Whether to add the USD rate to the fetch
  * @returns - Promise resolving to exchange rate for given currency
  */
- async fetchExchangeRate(currency: string, nativeCurrency = this.activeNativeCurrency): Promise<CurrencyRateState> {
- const json = await handleFetch(this.getPricingURL(currency, nativeCurrency));
+ async fetchExchangeRate(currency: string, nativeCurrency = this.activeNativeCurrency, includeUSDRate?: boolean): Promise<CurrencyRateState> {
+ const json = await handleFetch(this.getPricingURL(currency, nativeCurrency, includeUSDRate));
  const conversionRate = Number(json[currency.toUpperCase()]);
-
+ const usdConversionRate = Number(json.USD);
  if (!Number.isFinite(conversionRate)) {
  throw new Error(`Invalid response for ${currency.toUpperCase()}: ${json[currency.toUpperCase()]}`);
  }
+ if (includeUSDRate && !Number.isFinite(usdConversionRate)) {
+ throw new Error(`Invalid response for usdConversionRate: ${json.USD}`);
+ }
 
  return {
  conversionDate: Date.now() / 1000,
  conversionRate,
  currentCurrency: currency,
  nativeCurrency,
+ usdConversionRate,
  };
  }
 
@@ -157,16 +172,19 @@ export class CurrencyRateController extends BaseController<CurrencyRateConfig, C
  }
  const releaseLock = await this.mutex.acquire();
  try {
- const { conversionDate, conversionRate } = await this.fetchExchangeRate(
+ const { conversionDate, conversionRate, usdConversionRate } = await this.fetchExchangeRate(
  this.activeCurrency,
  this.activeNativeCurrency,
+ this.includeUSDRate,
  );
-this.update({
+const newState: CurrencyRateState = {
  conversionDate,
  conversionRate,
  currentCurrency: this.activeCurrency,
  nativeCurrency: this.activeNativeCurrency,
- });
+ usdConversionRate: this.includeUSDRate ? usdConversionRate : this.defaultState.usdConversionRate,
+ };
+ this.update(newState);
 
  return this.state;
  } finally {

tests/ComposableController.test.ts

@@ -40,6 +40,7 @@ describe('ComposableController', () => {
  conversionRate: 0,
  currentCurrency: 'usd',
  nativeCurrency: 'ETH',
+ usdConversionRate: 0,
  },
  EnsController: {
  ensEntries: {},
@@ -96,6 +97,7 @@ describe('ComposableController', () => {
  selectedAddress: '',
  suggestedAssets: [],
  tokens: [],
+ usdConversionRate: 0,
  });
  });
 
@@ -149,6 +151,7 @@ describe('ComposableController', () => {
  selectedAddress: '',
  suggestedAssets: [],
  tokens: [],
+ usdConversionRate: 0,
  });
  });
 

tests/CurrencyRateController.test.ts

@@ -5,7 +5,11 @@ import CurrencyRateController from '../src/assets/CurrencyRateController';
 
 describe('CurrencyRateController', () => {
  beforeEach(() => {
- fetchMock.mock('*', () => new Response(JSON.stringify({ USD: 1337 }))).spy();
+ fetchMock
+ .mock(/XYZ,USD/u, () => new Response(JSON.stringify({ XYZ: 123, USD: 456 })))
+ .mock(/DEF,USD/u, () => new Response(JSON.stringify({ DEF: 123 })))
+ .mock('*', () => new Response(JSON.stringify({ USD: 1337 })))
+ .spy();
  });
 
  afterEach(() => {
@@ -19,6 +23,7 @@ describe('CurrencyRateController', () => {
  conversionRate: 0,
  currentCurrency: 'usd',
  nativeCurrency: 'ETH',
+ usdConversionRate: 0,
  });
  });
 
@@ -29,6 +34,7 @@ describe('CurrencyRateController', () => {
  disabled: false,
  interval: 180000,
  nativeCurrency: 'ETH',
+ includeUSDRate: false,
  });
  });
 
@@ -40,6 +46,7 @@ describe('CurrencyRateController', () => {
  disabled: false,
  interval: 180000,
  nativeCurrency: 'ETH',
+ includeUSDRate: false,
  });
  });
 
@@ -89,13 +96,42 @@ describe('CurrencyRateController', () => {
  expect(controller.state.conversionRate).toBeGreaterThan(0);
  });
 
+ it('should add usd rate to state when includeUSDRate is configured true', async () => {
+ const controller = new CurrencyRateController({ includeUSDRate: true, currentCurrency: 'xyz' });
+ expect(controller.state.usdConversionRate).toEqual(0);
+ await controller.updateExchangeRate();
+ expect(controller.state.usdConversionRate).toEqual(456);
+ });
+
  it('should use default base asset', async () => {
  const nativeCurrency = 'FOO';
  const controller = new CurrencyRateController({ nativeCurrency });
  await controller.fetchExchangeRate('usd');
  expect(fetchMock.calls()[0][0]).toContain(nativeCurrency);
  });
 
+ it('should add usd rate to state fetches when configured', async () => {
+ const controller = new CurrencyRateController({ includeUSDRate: true });
+ const result = await controller.fetchExchangeRate('xyz', 'FOO', true);
+ expect(fetchMock.calls()[0][0]).toContain('XYZ,USD');
+ expect(result.usdConversionRate).toEqual(456);
+ expect(result.conversionRate).toEqual(123);
+ });
+
+ it('should throw correctly when configured to return usd but receives an invalid response for currentCurrency rate', async () => {
+ const controller = new CurrencyRateController({ includeUSDRate: true });
+ await expect(controller.fetchExchangeRate('abc', 'FOO', true)).rejects.toThrow(
+ 'Invalid response for ABC: undefined',
+ );
+ });
+
+ it('should throw correctly when configured to return usd but receives an invalid response for usdConversionRate', async () => {
+ const controller = new CurrencyRateController({ includeUSDRate: true });
+ await expect(controller.fetchExchangeRate('def', 'FOO', true)).rejects.toThrow(
+ 'Invalid response for usdConversionRate: undefined',
+ );
+ });
+
  describe('#fetchExchangeRate', () => {
  it('should handle a valid symbol in the API response', async () => {
  const controller = new CurrencyRateController({ nativeCurrency: 'usd' });