Arena Export Validator
This is designed as a validator designed around current Arena standards -- to be used to validate and confirm whether or not a platform's generated export format meets Arena's specs (as Arena has no officially published specs, I've tried to determine varied test cases including decks with both commanders and companions).
Assumed Format of Export Data
- There are four possible sections, that appear in the following sequence: Commander, Companion, Deck, Sideboard.
- The section title is the first line of each section.
- Blank lines are inserted after each section.
- If a line begins with an integer, it's a card. If it begins with anything else, it's a Section title.