I did it in 628. Then I realized there were free letters from the get-go. DandDangDang!

After this kata, you will feel an overwhelming sense of gratitude for having permit to type the letters of the alphabet.

Hats off! I found this one quite challenging!

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

Could you explain to me (s.length / 2 - 1) ? To me it is saying find the middle and move the index down one in case it is an even number string length so you can return both numbers. I don't get it, I do understand the deprication of substr and I used substring in my solution. Or if you could maybe explain what the (s.lenght / 2) - 1 means that will help as well.

• No random tests (must also generate cases below)

• Missing fixed, sample tests for valid cases below:

  • ########## ext. # (3-digit areacode + 3-digit local3 + 4-digit last4 + extension)
    --> aF[}2654871290D~]:gF;X012345

  • Above case with leading 1 --> wV: 15754437619At,xfD90 (Note: 1575 with leading 1)

  • 1(###) ###-#### (1 followed immediately by 3-digit areacode + 3-digit local3 + 4-digit last4)

    --> a1234-567AbCd8901~:)SD

  • (###) ####### ext. # (3-digit areacode + 7-digit combined (3-digit local3 + 4-digit last4) + extension)

    --> !046f*S;b J2634114 extensio91243445445

  • Above case with leading 1 --> !1046f*S;b J2634114 extensio91243445445 (Note 1046 instead of 046)

  • (###)### #### ext. # (6-digit combined (3-digit areacode + 3-digit local3) + 4-digit last4 + extension) --> 254780gR]}\~fdn dA1234zyXtdfd01234567

  • Above case with leading 1 --> 1254780gR]}\~fdn dA1234zyXtdfd01234567 (Note 1254780 instead of 254780)

A string also has a length property. Don't need to convert the string to an array with split().

substr is deprecated

Diagonal lines are tested, but the line drawing algorithm is not specified. There are at least several possible line drawing algorithms.

Does this kata require any specific node.js functionality?

Good code, but unnecessarily big.
No need to use Math.ceil (if you don't use decimal numbers) and ternary operator.
Check my solution.

Thanks! Mine was so ugly compared to this.