describe('Record modify operations', () => {
  it('modifies existing key', () => {
    const record = { a: 10, b: 20, c: 30 }
    const result = incrementKey(record, 'b')
    expect(result).toEqual({ a: 10, b: 21, c: 30 })
  })

  it('handles missing key', () => {
    const record = { a: 10 }
    const result = incrementKey(record, 'z')
    expect(result).toEqual({ a: 10 })
  })

  it('updates value at key', () => {
    const record = { name: 'Alice', city: 'Paris' }
    const result = updateAt(record, 'city', 'London')
    expect(result).toEqual({ name: 'Alice', city: 'London' })
  })
})