Shipping Scrabbly

What I built

Scrabbly is a command-line Scrabble trainer, and as of today it’s on npm. You install it with one command and get seven working commands: score, validate, train, find, master-word, help and credits. It checks words against Collins Scrabble Words 2019 (about 279,000 words), drills 2- and 3-letter words by starting letter, finds every word hiding in a rack of tiles (blanks included), and has a game where you draw 7 tiles from a real 100-tile bag and get three guesses at the highest-scoring word.

What was challenging

Making it work on someone else’s machine. Everything ran fine from my project folder, but a published package only includes what you tell npm to include. My first test install crashed on validate because words.txt hadn’t made it into the package at the time.

Blank tiles. A ? in the terminal is a wildcard to the shell, so it needs quotes: scrabbly find “ret?ins”. Scoring blanks was also easy to get wrong. A blank has to be spent only after your real tiles, or it quietly scores as the letter it replaces.

Flags. My plan had find -start qu, but Commander reads a single dash with a full word as five one-letter flags. It became –start, with -s as a short form.

What I am proud of

• The way the code is split. The functions that work things out (scoreWord, findWords, isValidWord) never print anything. That’s why the Master Word game came together quickly: it calls the same findWords that powers find to work out each round’s answer, so the game has no separate answer key to get wrong.
• Errors. Every mistake you can make, from a missing word to an unknown flag, gets the same styled message that says what went wrong and how to type it correctly.
• The look. Tile yellow, tan and wood brown, an animated title, ★ on the best word in each group, and tiles drawn with their points as subscripts (Q₁₀).
• That it exists. I started this because I wanted to learn two-letter words, and I now use it for that.

How to test Scrabbly

npm install -g scrabbly
scrabbly

You should see an animated title and a menu of commands. Try them out.

To try the two interactive modes:

• scrabbly train: choose 2-letter words, pick a letter yourself, and enter I. Type if id in it is, press Enter, then press Enter again on an empty line. It should tell you that you forgot IO. Add io and try again to see the perfect-score screen. Then try random mode and make a mistake on purpose.
• scrabbly master-word: guess something short and weak first and see it say your word is valid but not the master word. Then try a fake word like asdf, which shouldn’t cost you a guess.

Press Ctrl+C at any prompt to leave politely. To run it from source instead, see the “How to run it locally” section in the README.