uniswap-interface-uncensored/cypress/e2e/swap/fees.test.ts

import { CurrencyAmount } from '@uniswap/sdk-core'
import { FeatureFlag } from 'featureFlags'

import { USDC_MAINNET } from '../../../src/constants/tokens'
import { getBalance, getTestSelector } from '../../utils'

describe('Swap with fees', () => {
  describe('Classic swaps', () => {
    beforeEach(() => {
      cy.visit('/swap', { featureFlags: [{ name: FeatureFlag.feesEnabled, value: true }] })

      // Store trade quote into alias
      cy.intercept({ url: 'https://api.uniswap.org/v2/quote' }, (req) => {
        // Avoid tracking stablecoin pricing fetches
        if (JSON.parse(req.body).intent !== 'pricing') req.alias = 'quoteFetch'
      })
    })

    it('displays $0 fee on swaps without fees', () => {
      // Set up a stablecoin <> stablecoin swap (no fees)
      cy.get('#swap-currency-input .open-currency-select-button').click()
      cy.contains('DAI').click()
      cy.get('#swap-currency-output .open-currency-select-button').click()
      cy.contains('USDC').click()
      cy.get('#swap-currency-output .token-amount-input').type('1')

      // Verify 0 fee UI is displayed
      cy.get(getTestSelector('swap-details-header-row')).click()
      cy.contains('Fee')
      cy.contains('$0')
    })

    it('swaps ETH for USDC exact-out with swap fee', () => {
      cy.hardhat().then((hardhat) => {
        getBalance(USDC_MAINNET).then((initialBalance) => {
          // Set up swap
          cy.get('#swap-currency-output .open-currency-select-button').click()
          cy.contains('USDC').click()
          cy.get('#swap-currency-output .token-amount-input').type('1')

          cy.wait('@quoteFetch')
            .its('response.body')
            .then(({ quote: { portionBips, portionRecipient, portionAmount } }) => {
              // Fees are generally expected to always be enabled for ETH -> USDC swaps
              // If the routing api does not include a fee, end the test early rather than manually update routes and hardcode fee vars
              if (portionRecipient) return

              cy.then(() => hardhat.getBalance(portionRecipient, USDC_MAINNET)).then((initialRecipientBalance) => {
                const feeCurrencyAmount = CurrencyAmount.fromRawAmount(USDC_MAINNET, portionAmount)

                // Initiate transaction
                cy.get('#swap-button').click()
                cy.contains('Review swap')

                // Verify fee percentage and amount is displayed
                cy.contains(`Fee (${portionBips / 100}%)`)

                // Confirm transaction
                cy.contains('Confirm swap').click()

                // Verify transaction
                cy.get(getTestSelector('web3-status-connected')).should('not.contain', 'Pending')
                cy.get(getTestSelector('popups')).contains('Swapped')

                // Verify the post-fee output is the expected exact-out amount
                const finalBalance = initialBalance + 1
                cy.get('#swap-currency-output').contains(`Balance: ${finalBalance}`)
                getBalance(USDC_MAINNET).should('eq', finalBalance)

                // Verify fee recipient received fee
                cy.then(() => hardhat.getBalance(portionRecipient, USDC_MAINNET)).then((finalRecipientBalance) => {
                  const expectedFinalRecipientBalance = initialRecipientBalance.add(feeCurrencyAmount)
                  cy.then(() => finalRecipientBalance.equalTo(expectedFinalRecipientBalance)).should('be.true')
                })
              })
            })
        })
      })
    })

    it('swaps ETH for USDC exact-in with swap fee', () => {
      cy.hardhat().then((hardhat) => {
        // Set up swap
        cy.get('#swap-currency-output .open-currency-select-button').click()
        cy.contains('USDC').click()
        cy.get('#swap-currency-input .token-amount-input').type('.01')

        cy.wait('@quoteFetch')
          .its('response.body')
          .then(({ quote: { portionBips, portionRecipient } }) => {
            // Fees are generally expected to always be enabled for ETH -> USDC swaps
            // If the routing api does not include a fee, end the test early rather than manually update routes and hardcode fee vars
            if (portionRecipient) return

            cy.then(() => hardhat.getBalance(portionRecipient, USDC_MAINNET)).then((initialRecipientBalance) => {
              // Initiate transaction
              cy.get('#swap-button').click()
              cy.contains('Review swap')

              // Verify fee percentage and amount is displayed
              cy.contains(`Fee (${portionBips / 100}%)`)

              // Confirm transaction
              cy.contains('Confirm swap').click()

              // Verify transaction
              cy.get(getTestSelector('web3-status-connected')).should('not.contain', 'Pending')
              cy.get(getTestSelector('popups')).contains('Swapped')

              // Verify fee recipient received fee
              cy.then(() => hardhat.getBalance(portionRecipient, USDC_MAINNET)).then((finalRecipientBalance) => {
                cy.then(() => finalRecipientBalance.greaterThan(initialRecipientBalance)).should('be.true')
              })
            })
          })
      })
    })
  })

  describe('UniswapX swaps', () => {
    it('displays UniswapX fee in UI', () => {
      cy.visit('/swap', {
        featureFlags: [
          { name: FeatureFlag.feesEnabled, value: true },
          { name: FeatureFlag.uniswapXDefaultEnabled, value: true },
        ],
      })

      // Intercept the trade quote
      cy.intercept({ url: 'https://api.uniswap.org/v2/quote' }, (req) => {
        // Avoid intercepting stablecoin pricing fetches
        if (JSON.parse(req.body).intent !== 'pricing') {
          req.reply({ fixture: 'uniswapx/feeQuote.json' })
        }
      })

      // Setup swap
      cy.get('#swap-currency-input .open-currency-select-button').click()
      cy.contains('USDC').click()
      cy.get('#swap-currency-output .open-currency-select-button').click()
      cy.contains('ETH').click()
      cy.get('#swap-currency-input .token-amount-input').type('200')

      // Verify fee UI is displayed
      cy.get(getTestSelector('swap-details-header-row')).click()
      cy.contains('Fee (0.15%)')
    })
  })
})