metamask-extension/ui/app/hooks/tests/useCurrencyDisplay.test.js

import assert from 'assert'
import { renderHook } from '@testing-library/react-hooks'
import * as reactRedux from 'react-redux'
import { useCurrencyDisplay } from '../useCurrencyDisplay'
import sinon from 'sinon'
import { getCurrentCurrency, getNativeCurrency, getConversionRate } from '../../selectors'

const tests = [
  {
    input: {
      value: '0x2386f26fc10000',
      numberOfDecimals: 2,
      currency: 'usd',
    },
    result: {
      value: '$2.80',
      suffix: 'USD',
      displayValue: '$2.80 USD',
    },
  },
  {
    input: {
      value: '0x2386f26fc10000',
      currency: 'usd',
    },
    result: {
      value: '$2.80',
      suffix: 'USD',
      displayValue: '$2.80 USD',
    },
  },
  {
    input: {
      value: '0x1193461d01595930',
      currency: 'ETH',
      numberOfDecimals: 3,
    },
    result: {
      value: '1.266',
      suffix: 'ETH',
      displayValue: '1.266 ETH',
    },
  },
  {
    input: {
      value: '0x1193461d01595930',
      currency: 'ETH',
      numberOfDecimals: 3,
      hideLabel: true,
    },
    result: {
      value: '1.266',
      suffix: undefined,
      displayValue: '1.266',
    },
  },
  {
    input: {
      value: '0x3b9aca00',
      currency: 'ETH',
      denomination: 'GWEI',
      hideLabel: true,
    },
    result: {
      value: '1',
      suffix: undefined,
      displayValue: '1',
    },
  },
  {
    input: {
      value: '0x3b9aca00',
      currency: 'ETH',
      denomination: 'WEI',
      hideLabel: true,
    },
    result: {
      value: '1000000000',
      suffix: undefined,
      displayValue: '1000000000',
    },
  },
  {
    input: {
      value: '0x3b9aca00',
      currency: 'ETH',
      numberOfDecimals: 100,
      hideLabel: true,
    },
    result: {
      value: '0.000000001',
      suffix: undefined,
      displayValue: '0.000000001',
    },
  },
]


describe('useCurrencyDisplay', function () {
  tests.forEach(({ input: { value, ...restProps }, result }) => {
    describe(`when input is { value: ${value}, decimals: ${restProps.numberOfDecimals}, denomation: ${restProps.denomination} }`, function () {
      const stub = sinon.stub(reactRedux, 'useSelector')
      stub.callsFake((selector) => {
        if (selector === getCurrentCurrency) {
          return 'usd'
        } else if (selector === getNativeCurrency) {
          return 'ETH'
        } else if (selector === getConversionRate) {
          return 280.45
        }
      })
      const hookReturn = renderHook(() => useCurrencyDisplay(value, restProps))
      const [ displayValue, parts ] = hookReturn.result.current
      stub.restore()
      it(`should return ${result.displayValue} as displayValue`, function () {
        assert.equal(displayValue, result.displayValue)
      })
      it(`should return ${result.value} as value`, function () {
        assert.equal(parts.value, result.value)
      })
      it(`should return ${result.suffix} as suffix`, function () {
        assert.equal(parts.suffix, result.suffix)
      })
    })
  })
})