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to Phone Number in the TypeScript Track

Published at Jul 26 2019 · 0 comments
Instructions
Test suite
Solution

Clean up user-entered phone numbers so that they can be sent SMS messages.

The North American Numbering Plan (NANP) is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code: 1.

NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as area code, followed by a seven-digit local number. The first three digits of the local number represent the exchange code, followed by the unique four-digit number which is the subscriber number.

The format is usually represented as

(NXX)-NXX-XXXX

where N is any digit from 2 through 9 and X is any digit from 0 through 9.

Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code (1) if present.

For example, the inputs

  • +1 (613)-995-0253
  • 613-995-0253
  • 1 613 995 0253
  • 613.995.0253

should all produce the output

6139950253

Note: As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.

Setup

Go through the setup instructions for TypeScript to install the necessary dependencies:

https://exercism.io/tracks/typescript/installation

Requirements

Install assignment dependencies:

$ yarn install

Making the test suite pass

Execute the tests with:

$ yarn test

In the test suites all tests but the first have been skipped.

Once you get a test passing, you can enable the next one by changing xit to it.

Source

Event Manager by JumpstartLab http://tutorials.jumpstartlab.com/projects/eventmanager.html

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

phone-number.test.ts

import PhoneNumber from './phone-number'

describe('PhoneNumber()', () => {

  it('cleans the number', () => {
    const phone = new PhoneNumber('(223) 456-7890')
    expect(phone.number()).toEqual('2234567890')
  })

  xit('cleans numbers with dots', () => {
    const phone = new PhoneNumber('223.456.7890')
    expect(phone.number()).toEqual('2234567890')
  })

  xit('cleans numbers with multiple spaces', () => {
    const phone = new PhoneNumber('223 456   7890   ')
    expect(phone.number()).toEqual('2234567890')
  })

  xit('invalid when 9 digits', () => {
    const phone = new PhoneNumber('123456789')
    expect(phone.number()).toEqual(undefined)
  })

  xit('invalid when 11 digits', () => {
    const phone = new PhoneNumber('21234567890')
    expect(phone.number()).toEqual(undefined)
  })

  xit('valid when 11 digits and starting with 1', () => {
    const phone = new PhoneNumber('11234567890')
    expect(phone.number()).toEqual('1234567890')
  })

  xit('invalid when 12 digits', () => {
    const phone = new PhoneNumber('321234567890')
    expect(phone.number()).toEqual(undefined)
  })

  xit('invalid with letters', () => {
    const phone = new PhoneNumber('123-abc-7890')
    expect(phone.number()).toEqual(undefined)
  })

  xit('invalid with punctuations', () => {
    const phone = new PhoneNumber('123-@:!-7890')
    expect(phone.number()).toEqual(undefined)
  })

  xit('invalid with right number of digits but letters mixed in', () => {
    const phone = new PhoneNumber('1a2b3c4d5e6f7g8h9i0j')
    expect(phone.number()).toEqual(undefined)
  })

})
export default class PhoneNumber {
  constructor(readonly phoneNumber: string) {}

  public number() {
    const num = this.phoneNumber.replace(/[()\+\-. ]/g, '')

    if (/[a-zA-Z~`!@#$%^&*(){}\[\];:"'<,.>?\/\\|_+=-]/g.test(num)) {
      return undefined
    }

    if (num.length === 10) {
      return num
    }

    if (num.length === 11 && num[0] === '1') {
      return num.slice(1)
    }

    return undefined
  }
}

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