NguyenVietLinh

Problem 1 :

• Please look for the solution file sum.ts. I included the test function inside.

Problem 2 :

• Please open /fancy-form folder. I created using create-react-app with Tailwind for styling.
• The tokens list is fetch from the API you provided.
• To start swapping tokens, please select each tokens and input the amount.
• Some functions I provided :
  • Select Token, search Token by name
  • Validate same token for swapping and input amount.
  • Get rate based on selected pairs of tokens.
  • Mocked API call by setTimeout 3s after swap.
  • Show currency rate below.
  • Add ability to switch pair for better UX.
• Prerequisites: Node v.18+
• Run yarn => yarn start to start the project.

Problem 3 :

• For the issues in the code, I added some details as comments and separate to a new file named refactor.tsx.

• These are the changes I made:

  • Define type for blockchain in getPriority function.
  • Define type TokenPrice for state prices
  • Add field blockchain with type Blockchain to WalletBalance interface
  • Extend FormattedWalletBalance from the WalletBalance interface for better reusability.
  • Define body of class Datasource with property sourceUrl and function getPrices to get prices of token from sourceUrl
  • Fix error console.err to console.error on useEffect
  • Merge the cases for 'Zilliqa' and 'Neo' since they have the same priority value.
  • Change lhsPriority to balancePriority since there's no variable lhsPriority. I assume it's balancePriority since it's not used.
  • Add type FormattedWalletBalance[] for useMemo.
  • Rewrite sortBalances calculation with shorter format and unnecessary if condition and replace return as -1 and 1 by a sub function.
  • Rename variables in sort function to more clearly.
  • Add map function to convert array from WalletBalance to FormattedWalletBalance.
  • Comment formattedBalances as it is not used.
  • Missing export default so i added it.
  • Use balance.currency as key instead of index because it is not recommend in React and will causes issues with reordering

Please contact me through my email if anything I do is unclear. Thanks for your time!