Either

Get Or Else

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Learn about get or else in fp-ts either

Code Editor

07-get-or-else.exercise.ts

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Test Results

Requirements

describe('getUserName', () => {
  const userRight: E.Either<UserError, User> = E.right({ id: 1, name: 'Alice' })
  const userLeft: E.Either<UserError, User> = E.left('User not found')

  it('returns user name for right value', () => {
    const result = getUserName(userRight)
    expect(result).toEqual('Alice')
  })

  it('returns default value for left', () => {
    const result = getUserName(userLeft)
    expect(result).toEqual('Anonymous')
  })
})
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Pro Tips

💡 Stuck? Here's what to try:

  • • Read the comments in the code carefully
  • • Run tests frequently to get feedback
  • • Check the fp-ts documentation
  • • Use the solution if you need help

🚀 Learning Approach:

  • • Focus on understanding, not just solving
  • • Experiment with different approaches
  • • Think about real-world applications
  • • Build on previous exercises