This converter is able to convert Arabic numbers between 1 and 3999.
That small app shows how I use TDD. If you're interested in that, please analyze the whole git history. I've tried to commit changes as frequently as possible to show every stage of TDD.
I've made a 'codesandbox' branch with the changes which are needed to import the repository to Codesandbox. Codesandbox does not deal with *.svg files. The Logo.svg import was removed from the 'codesandbox' branch.
Codesandbox doesn't have functionality to change branches after creating a sandbox. If you want to import a branch other than the main branch, go to the github page, change the branch and copy the url from your browser, eg.: https://github.com/mkiszka/roman.react/tree/codesandbox