refactor xmr rate module to exchange rate module for multi crypto support

backend/src/modules/exchangeRate/ExchangeRateModule.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common';
+import { ExchangeRateService } from './services/ExchangeRateService';
+
+@Module({
+    providers: [ExchangeRateService],
+    exports: [ExchangeRateService]
+})
+export class ExchangeRateModule {}

backend/src/modules/exchangeRate/const/coinPaprikaIds.ts

@@ -0,0 +1,7 @@
+import type { ExchangeRatePaymentMethod } from './exchangeRatePaymentMethods';
+import { PaymentMethod } from '../../payment/types/PaymentMethod';
+
+export const COINPAPRIKA_ID_BY_PAYMENT_METHOD = {
+    [PaymentMethod.Xmr]: 'xmr-monero',
+    [PaymentMethod.Btc]: 'btc-bitcoin'
+} as const satisfies Record<ExchangeRatePaymentMethod, string>;

backend/src/modules/exchangeRate/const/coingeckoIds.ts

@@ -0,0 +1,7 @@
+import type { ExchangeRatePaymentMethod } from './exchangeRatePaymentMethods';
+import { PaymentMethod } from '../../payment/types/PaymentMethod';
+
+export const COINGECKO_ID_BY_PAYMENT_METHOD = {
+    [PaymentMethod.Xmr]: 'monero',
+    [PaymentMethod.Btc]: 'bitcoin'
+} as const satisfies Record<ExchangeRatePaymentMethod, string>;

backend/src/modules/exchangeRate/const/exchangeRatePaymentMethods.ts

@@ -0,0 +1,5 @@
+import { PaymentMethod } from '../../payment/types/PaymentMethod';
+
+export const EXCHANGE_RATE_PAYMENT_METHODS = [PaymentMethod.Xmr, PaymentMethod.Btc] as const;
+
+export type ExchangeRatePaymentMethod = (typeof EXCHANGE_RATE_PAYMENT_METHODS)[number];

backend/src/modules/exchangeRate/dto/CoinPaprikaTickerResponseDto.ts

@@ -0,0 +1,43 @@
+import {
+    IsEnum,
+    IsNotEmpty,
+    Validate,
+    ValidatorConstraint,
+    type ValidationArguments,
+    type ValidatorConstraintInterface
+} from 'class-validator';
+import { ShopFiatCurrency } from '../../../types/ShopFiatCurrency';
+
+@ValidatorConstraint({ name: 'coinPaprikaResponse' })
+class CoinPaprikaResponseConstraint implements ValidatorConstraintInterface {
+    validate(response: unknown, args: ValidationArguments): boolean {
+        const { shopFiatCurrency } = args.object as CoinPaprikaTickerResponseDto;
+
+        if (!shopFiatCurrency || typeof response !== 'object' || response === null) {
+            return false;
+        }
+
+        const quotes = (response as { quotes?: unknown }).quotes;
+
+        if (typeof quotes !== 'object' || quotes === null) {
+            return false;
+        }
+
+        const quote = (quotes as Record<string, { price?: number }>)[shopFiatCurrency];
+
+        return typeof quote?.price === 'number' && Number.isFinite(quote.price) && quote.price > 0;
+    }
+
+    defaultMessage(): string {
+        return 'CoinPaprika fiat quote price must be a positive number';
+    }
+}
+
+export class CoinPaprikaTickerResponseDto {
+    @IsEnum(ShopFiatCurrency)
+    shopFiatCurrency: ShopFiatCurrency;
+
+    @IsNotEmpty()
+    @Validate(CoinPaprikaResponseConstraint)
+    response: { quotes: Record<string, { price: number }> };
+}

backend/src/modules/exchangeRate/dto/CoingeckoSimplePriceResponseDto.ts

@@ -0,0 +1,55 @@
+import {
+    IsArray,
+    IsEnum,
+    IsNotEmpty,
+    IsObject,
+    IsString,
+    Validate,
+    ValidatorConstraint,
+    type ValidationArguments,
+    type ValidatorConstraintInterface
+} from 'class-validator';
+import { ShopFiatCurrency } from '../../../types/ShopFiatCurrency';
+
+@ValidatorConstraint({ name: 'coingeckoResponse' })
+class CoingeckoResponseConstraint implements ValidatorConstraintInterface {
+    validate(response: Record<string, unknown>, args: ValidationArguments): boolean {
+        const { shopFiatCurrency, coinIds } = args.object as CoingeckoSimplePriceResponseDto;
+
+        if (!shopFiatCurrency || coinIds.length === 0) {
+            return false;
+        }
+
+        const fiatKey = shopFiatCurrency.toLowerCase();
+
+        return coinIds.every(coinId => {
+            const coin = response[coinId];
+
+            if (typeof coin !== 'object' || coin === null) {
+                return false;
+            }
+
+            const rate = coin[fiatKey];
+
+            return typeof rate === 'number' && Number.isFinite(rate) && rate > 0;
+        });
+    }
+
+    defaultMessage(): string {
+        return 'CoinGecko coin fiat rate must be a positive number';
+    }
+}
+
+export class CoingeckoSimplePriceResponseDto {
+    @IsEnum(ShopFiatCurrency)
+    shopFiatCurrency: ShopFiatCurrency;
+
+    @IsArray()
+    @IsString({ each: true })
+    coinIds: string[];
+
+    @IsNotEmpty()
+    @IsObject()
+    @Validate(CoingeckoResponseConstraint)
+    response: Record<string, Record<string, number>>;
+}

backend/src/modules/exchangeRate/services/ExchangeRateService.spec.ts

@@ -0,0 +1,245 @@
+import { Logger } from '@nestjs/common';
+import type { ConfigService } from '@nestjs/config';
+import axios from 'axios';
+import { PaymentMethod } from '../../payment/types/PaymentMethod';
+import { ExchangeRateService } from './ExchangeRateService';
+
+jest.mock('axios');
+
+const mockedAxios = axios as jest.Mocked<typeof axios>;
+
+const buildCoinPaprikaTicker = (price: number, fiat = 'USD') => ({
+    quotes: { [fiat]: { price } }
+});
+
+const buildCoinPaprikaAxiosMock =
+    (xmrPrice: number, btcPrice: number, fiat = 'USD') =>
+    (url: string) => {
+        if (url === `https://coinpaprika.test/v1/tickers/xmr-monero?quotes=${fiat}`) {
+            return Promise.resolve({ data: buildCoinPaprikaTicker(xmrPrice, fiat) });
+        }
+
+        if (url === `https://coinpaprika.test/v1/tickers/btc-bitcoin?quotes=${fiat}`) {
+            return Promise.resolve({ data: buildCoinPaprikaTicker(btcPrice, fiat) });
+        }
+
+        return Promise.reject(new Error(`unexpected url: ${url}`));
+    };
+
+describe('ExchangeRateService', () => {
+    let service: ExchangeRateService;
+    let configService: {
+        get: jest.Mock;
+    };
+    let warnLogSpy: jest.SpiedFunction<typeof Logger.prototype.warn>;
+    let errorLogSpy: jest.SpiedFunction<typeof Logger.prototype.error>;
+    let logSpy: jest.SpiedFunction<typeof Logger.prototype.log>;
+
+    beforeEach(() => {
+        warnLogSpy = jest.spyOn(Logger.prototype, 'warn').mockImplementation(() => undefined);
+        errorLogSpy = jest.spyOn(Logger.prototype, 'error').mockImplementation(() => undefined);
+        logSpy = jest.spyOn(Logger.prototype, 'log').mockImplementation(() => undefined);
+
+        configService = {
+            get: jest.fn((key: string) => {
+                if (key === 'shopSettings') {
+                    return { shopFiatCurrency: 'USD' };
+                }
+
+                if (key === 'coingecko') {
+                    return { apiBaseUrl: 'https://coingecko.test', rateFetchTimeoutMs: 5000 };
+                }
+
+                if (key === 'coinPaprika') {
+                    return { apiBaseUrl: 'https://coinpaprika.test/v1', rateFetchTimeoutMs: 5000 };
+                }
+
+                return undefined;
+            })
+        };
+
+        service = new ExchangeRateService(configService as unknown as ConfigService);
+        mockedAxios.get.mockReset();
+    });
+
+    afterEach(() => {
+        warnLogSpy.mockRestore();
+        errorLogSpy.mockRestore();
+        logSpy.mockRestore();
+    });
+
+    it('stores batched CoinGecko rates when the fetch succeeds', async () => {
+        mockedAxios.get.mockResolvedValueOnce({
+            data: {
+                monero: { usd: 152.3456 },
+                bitcoin: { usd: 95_432.1987 }
+            }
+        });
+
+        await service.fetchLiveRates();
+
+        expect(mockedAxios.get).toHaveBeenCalledWith(
+            'https://coingecko.test/simple/price?ids=monero,bitcoin&vs_currencies=usd',
+            { timeout: 5000 }
+        );
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(152.35);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(95_432.2);
+    });
+
+    it('falls back to CoinPaprika when CoinGecko fails', async () => {
+        mockedAxios.get
+            .mockRejectedValueOnce(new Error('coingecko down'))
+            .mockImplementation(buildCoinPaprikaAxiosMock(149.876, 94_999.5));
+
+        await service.fetchLiveRates();
+
+        expect(warnLogSpy).toHaveBeenCalled();
+        expect(mockedAxios.get).toHaveBeenCalledWith(
+            'https://coinpaprika.test/v1/tickers/xmr-monero?quotes=USD',
+            { timeout: 5000 }
+        );
+        expect(mockedAxios.get).toHaveBeenCalledWith(
+            'https://coinpaprika.test/v1/tickers/btc-bitcoin?quotes=USD',
+            { timeout: 5000 }
+        );
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(149.88);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(94_999.5);
+    });
+
+    it('leaves cached rates null when both providers fail on the first fetch', async () => {
+        mockedAxios.get
+            .mockRejectedValueOnce(new Error('coingecko down'))
+            .mockRejectedValue(new Error('coinpaprika down'));
+
+        await service.fetchLiveRates();
+
+        expect(errorLogSpy).toHaveBeenCalled();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBeNull();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBeNull();
+    });
+
+    it('falls back to CoinPaprika when CoinGecko returns an invalid payload', async () => {
+        mockedAxios.get
+            .mockResolvedValueOnce({ data: { monero: { usd: -1 }, bitcoin: { usd: 95_000 } } })
+            .mockImplementation(buildCoinPaprikaAxiosMock(151.11, 95_111.11));
+
+        await service.fetchLiveRates();
+
+        expect(warnLogSpy).toHaveBeenCalled();
+        expect(logSpy).toHaveBeenCalledWith('Successfully fetched live rates from CoinPaprika for USD');
+        expect(mockedAxios.get).toHaveBeenCalledTimes(3);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(151.11);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(95_111.11);
+    });
+
+    it('falls back to CoinPaprika when CoinGecko omits a coin', async () => {
+        mockedAxios.get
+            .mockResolvedValueOnce({ data: { monero: { usd: 150 } } })
+            .mockImplementation(buildCoinPaprikaAxiosMock(149.5, 94_000));
+
+        await service.fetchLiveRates();
+
+        expect(warnLogSpy).toHaveBeenCalled();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(149.5);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(94_000);
+    });
+
+    it('leaves cached rates null when CoinPaprika returns an invalid payload for one coin', async () => {
+        mockedAxios.get.mockRejectedValueOnce(new Error('coingecko down')).mockImplementation((url: string) => {
+            if (url === 'https://coinpaprika.test/v1/tickers/xmr-monero?quotes=USD') {
+                return Promise.resolve({ data: buildCoinPaprikaTicker(151.11) });
+            }
+
+            if (url === 'https://coinpaprika.test/v1/tickers/btc-bitcoin?quotes=USD') {
+                return Promise.resolve({ data: { quotes: { USD: { price: -1 } } } });
+            }
+
+            return Promise.reject(new Error(`unexpected url: ${url}`));
+        });
+
+        await service.fetchLiveRates();
+
+        expect(errorLogSpy).toHaveBeenCalled();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBeNull();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBeNull();
+    });
+
+    it('keeps the previous live rates when a refresh fails after a successful fetch', async () => {
+        mockedAxios.get.mockResolvedValueOnce({
+            data: {
+                monero: { usd: 140 },
+                bitcoin: { usd: 90_000 }
+            }
+        });
+        await service.fetchLiveRates();
+
+        mockedAxios.get
+            .mockRejectedValueOnce(new Error('coingecko down'))
+            .mockRejectedValue(new Error('coinpaprika down'));
+        await service.fetchLiveRates();
+
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(140);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(90_000);
+    });
+
+    it('keeps the previous live rates when CoinPaprika returns an invalid payload for one coin on refresh', async () => {
+        mockedAxios.get.mockResolvedValueOnce({
+            data: {
+                monero: { usd: 140 },
+                bitcoin: { usd: 90_000 }
+            }
+        });
+        await service.fetchLiveRates();
+
+        mockedAxios.get.mockRejectedValueOnce(new Error('coingecko down')).mockImplementation((url: string) => {
+            if (url === 'https://coinpaprika.test/v1/tickers/xmr-monero?quotes=USD') {
+                return Promise.resolve({ data: buildCoinPaprikaTicker(151.11) });
+            }
+
+            if (url === 'https://coinpaprika.test/v1/tickers/btc-bitcoin?quotes=USD') {
+                return Promise.resolve({ data: { quotes: { USD: { price: -1 } } } });
+            }
+
+            return Promise.reject(new Error(`unexpected url: ${url}`));
+        });
+        await service.fetchLiveRates();
+
+        expect(errorLogSpy).toHaveBeenCalled();
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(140);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(90_000);
+    });
+
+    it('uses the shop fiat currency when building provider URLs', async () => {
+        configService.get.mockImplementation((key: string) => {
+            if (key === 'shopSettings') {
+                return { shopFiatCurrency: 'EUR' };
+            }
+
+            if (key === 'coingecko') {
+                return { apiBaseUrl: 'https://coingecko.test', rateFetchTimeoutMs: 5000 };
+            }
+
+            if (key === 'coinPaprika') {
+                return { apiBaseUrl: 'https://coinpaprika.test/v1', rateFetchTimeoutMs: 5000 };
+            }
+
+            return undefined;
+        });
+
+        mockedAxios.get.mockResolvedValueOnce({
+            data: {
+                monero: { eur: 130.5 },
+                bitcoin: { eur: 88_000.4 }
+            }
+        });
+
+        await service.fetchLiveRates();
+
+        expect(mockedAxios.get).toHaveBeenCalledWith(
+            'https://coingecko.test/simple/price?ids=monero,bitcoin&vs_currencies=eur',
+            { timeout: 5000 }
+        );
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Xmr)).toBe(130.5);
+        expect(service.getLiveFiatPerCrypto(PaymentMethod.Btc)).toBe(88_000.4);
+    });
+});

backend/src/modules/exchangeRate/services/ExchangeRateService.ts

@@ -0,0 +1,156 @@
+import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { Cron, CronExpression } from '@nestjs/schedule';
+import { plainToInstance } from 'class-transformer';
+import { validateSync } from 'class-validator';
+import axios from 'axios';
+import type { Config } from '../../../types/Config';
+import { getErrorMessage } from '../../../utils/getErrorMessage';
+import { COINGECKO_ID_BY_PAYMENT_METHOD } from '../const/coingeckoIds';
+import { COINPAPRIKA_ID_BY_PAYMENT_METHOD } from '../const/coinPaprikaIds';
+import { EXCHANGE_RATE_PAYMENT_METHODS, type ExchangeRatePaymentMethod } from '../const/exchangeRatePaymentMethods';
+import { CoingeckoSimplePriceResponseDto } from '../dto/CoingeckoSimplePriceResponseDto';
+import { CoinPaprikaTickerResponseDto } from '../dto/CoinPaprikaTickerResponseDto';
+import type { FiatPerCryptoRates } from '../types/FiatPerCryptoRates';
+import { extractCoingeckoSimplePrice } from '../utils/extractCoingeckoSimplePrice';
+import { extractCoinPaprikaTickerPrice } from '../utils/extractCoinPaprikaTickerPrice';
+
+@Injectable()
+export class ExchangeRateService implements OnModuleInit {
+    private readonly logger = new Logger(ExchangeRateService.name);
+
+    private liveFiatPerCrypto = Object.fromEntries(
+        EXCHANGE_RATE_PAYMENT_METHODS.map(method => [method, null])
+    ) as Record<ExchangeRatePaymentMethod, number | null>;
+
+    constructor(private readonly configService: ConfigService) {}
+
+    async onModuleInit(): Promise<void> {
+        await this.fetchLiveRates();
+    }
+
+    getLiveFiatPerCrypto(method: ExchangeRatePaymentMethod): number | null {
+        return this.liveFiatPerCrypto[method];
+    }
+
+    @Cron(CronExpression.EVERY_5_MINUTES)
+    async fetchLiveRates(): Promise<void> {
+        const { shopFiatCurrency } = this.configService.get('shopSettings') as Config['shopSettings'];
+
+        try {
+            const rates = await this.fetchRatesFromCoingecko();
+
+            this.applyRates(rates);
+        } catch {
+            this.logger.warn(`CoinGecko rate fetch failed for ${shopFiatCurrency}, trying CoinPaprika`);
+
+            try {
+                const rates = await this.fetchRatesFromCoinPaprika();
+
+                this.applyRates(rates);
+
+                this.logger.log(`Successfully fetched live rates from CoinPaprika for ${shopFiatCurrency}`);
+            } catch (error) {
+                this.logger.error(
+                    `Failed to fetch live rates from CoinGecko and CoinPaprika for ${shopFiatCurrency}: ${getErrorMessage(error)}`
+                );
+            }
+        }
+    }
+
+    private async fetchRatesFromCoingecko(): Promise<FiatPerCryptoRates> {
+        const { rateFetchTimeoutMs } = this.configService.get('coingecko') as Config['coingecko'];
+        const { shopFiatCurrency } = this.configService.get('shopSettings') as Config['shopSettings'];
+
+        const url = this.buildCoingeckoRateUrl();
+
+        const { data } = await axios.get<unknown>(url, {
+            timeout: rateFetchTimeoutMs
+        });
+
+        const coinIds = EXCHANGE_RATE_PAYMENT_METHODS.map(method => COINGECKO_ID_BY_PAYMENT_METHOD[method]);
+
+        const dto = plainToInstance(CoingeckoSimplePriceResponseDto, {
+            response: data,
+            shopFiatCurrency,
+            coinIds
+        });
+
+        const errors = validateSync(dto);
+
+        if (errors.length > 0) {
+            throw new Error('CoinGecko response validation failed');
+        }
+
+        const rates = {} as FiatPerCryptoRates;
+
+        for (const method of EXCHANGE_RATE_PAYMENT_METHODS) {
+            const coinId = COINGECKO_ID_BY_PAYMENT_METHOD[method];
+
+            const price = extractCoingeckoSimplePrice(dto.response, coinId, shopFiatCurrency);
+
+            if (price === null) {
+                throw new Error(`CoinGecko response validation failed for coin ${coinId}`);
+            }
+
+            rates[method] = price;
+        }
+
+        return rates;
+    }
+
+    private async fetchRatesFromCoinPaprika(): Promise<FiatPerCryptoRates> {
+        const { apiBaseUrl, rateFetchTimeoutMs } = this.configService.get('coinPaprika') as Config['coinPaprika'];
+        const { shopFiatCurrency } = this.configService.get('shopSettings') as Config['shopSettings'];
+
+        const rates = {} as FiatPerCryptoRates;
+
+        await Promise.all(
+            EXCHANGE_RATE_PAYMENT_METHODS.map(async method => {
+                const coinId = COINPAPRIKA_ID_BY_PAYMENT_METHOD[method];
+                const url = `${apiBaseUrl}/tickers/${coinId}?quotes=${shopFiatCurrency}`;
+
+                const { data } = await axios.get<unknown>(url, {
+                    timeout: rateFetchTimeoutMs
+                });
+
+                const dto = plainToInstance(CoinPaprikaTickerResponseDto, {
+                    response: data,
+                    shopFiatCurrency
+                });
+
+                const errors = validateSync(dto);
+
+                if (errors.length > 0) {
+                    throw new Error(`CoinPaprika response validation failed for coin ${coinId}`);
+                }
+
+                const price = extractCoinPaprikaTickerPrice(dto.response, shopFiatCurrency);
+
+                if (price === null) {
+                    throw new Error(`CoinPaprika response validation failed for coin ${coinId}`);
+                }
+
+                rates[method] = price;
+            })
+        );
+
+        return rates;
+    }
+
+    private buildCoingeckoRateUrl(): string {
+        const { apiBaseUrl } = this.configService.get('coingecko') as Config['coingecko'];
+        const { shopFiatCurrency } = this.configService.get('shopSettings') as Config['shopSettings'];
+
+        const coinIds = EXCHANGE_RATE_PAYMENT_METHODS.map(method => COINGECKO_ID_BY_PAYMENT_METHOD[method]).join(',');
+        const vs = shopFiatCurrency.toLowerCase();
+
+        return `${apiBaseUrl}/simple/price?ids=${coinIds}&vs_currencies=${vs}`;
+    }
+
+    private applyRates(rates: FiatPerCryptoRates): void {
+        for (const method of EXCHANGE_RATE_PAYMENT_METHODS) {
+            this.liveFiatPerCrypto[method] = rates[method];
+        }
+    }
+}

backend/src/modules/exchangeRate/types/FiatPerCryptoRates.ts

@@ -0,0 +1,3 @@
+import type { ExchangeRatePaymentMethod } from '../const/exchangeRatePaymentMethods';
+
+export type FiatPerCryptoRates = Record<ExchangeRatePaymentMethod, number>;

backend/src/modules/exchangeRate/utils/extractCoinPaprikaTickerPrice.ts

@@ -0,0 +1,25 @@
+import Decimal from 'decimal.js';
+import type { ShopFiatCurrency } from '../../../types/ShopFiatCurrency';
+
+export const extractCoinPaprikaTickerPrice = (
+    response: { quotes: Record<string, { price: number }> },
+    shopFiatCurrency: ShopFiatCurrency
+): number | null => {
+    const quote = response.quotes[shopFiatCurrency];
+
+    if (!quote) {
+        return null;
+    }
+
+    const rate = quote.price;
+
+    if (typeof rate !== 'number' || !Number.isFinite(rate) || rate <= 0) {
+        return null;
+    }
+
+    try {
+        return new Decimal(rate).toDecimalPlaces(2).toNumber();
+    } catch {
+        return null;
+    }
+};

backend/src/modules/exchangeRate/utils/extractCoingeckoSimplePrice.ts

@@ -0,0 +1,28 @@
+import Decimal from 'decimal.js';
+import type { ShopFiatCurrency } from '../../../types/ShopFiatCurrency';
+
+export const extractCoingeckoSimplePrice = (
+    coins: Record<string, Record<string, number>>,
+    coinId: string,
+    shopFiatCurrency: ShopFiatCurrency
+): number | null => {
+    const coin = coins[coinId];
+
+    if (!coin) {
+        return null;
+    }
+
+    const fiatKey = shopFiatCurrency.toLowerCase();
+
+    const rate = coin[fiatKey];
+
+    if (typeof rate !== 'number' || !Number.isFinite(rate) || rate <= 0) {
+        return null;
+    }
+
+    try {
+        return new Decimal(rate).toDecimalPlaces(2).toNumber();
+    } catch {
+        return null;
+    }
+};