Basic Racket solution for the gilded rose kata.

• Racket, which you can get download here or, if you're on macOS, run brew cask install racket.

raco test gilded-rose.rkt

> raco test: (submod "gilded-rose.rkt" test)
> 19 success(es) 0 failure(s) 0 error(s) 19 test(s) run
> 0
> 19 tests passed

racket cli/main.rkt

This will execute a 31-day cycle and print the output to stdout.

Alternatively you can run redirect the output to a file, actual.txt and compare it with expected.txt:

racket main.rkt > actual.txt
diff expected.txt actual.txt

The output should be something along the lines of:

1c1
< expected
---
> actual
24c24
< Conjured Mana Cake, 2, 5
---
> Conjured Mana Cake, 2, 4
36c36
< Conjured Mana Cake, 1, 4
---
> Conjured Mana Cake, 1, 2
48c48
< Conjured Mana Cake, 0, 3
---
> Conjured Mana Cake, 0, 0
60c60
< Conjured Mana Cake, -1, 1
---
> Conjured Mana Cake, -1, 0

It's unclear to me if the TextTests are wrong: the way Conjured items devaluate in the test file seems to not respect the definition, i.e.

“Conjured” items degrade in Quality twice as fast as normal items

racket web/main.rkt

This will start a web-server listening on port 8000, and launch the application in your default browser. It'll display a table containing your store's inventory, and a "next" button, which will update the current day.