Unofficial Hombrew Cask for Audacity 2.3.3 (recent 64-bit version). Get around Fosshub's limitations

audacity.rb

# Unofficial Hombrew Cask for Audacity 2.3.3 (recent 64-bit version) 
# Made entirely for fun and to demonstrate how to get around fosshub's limitations.

# Problem: Audacity's binary is hosted on fosshub and they don't provide a fixed url! The seems to intentionally try to prevent "hot-linking".
# Solution: Make a request to fosshub's special XHR endpoint to get the signed download url.  Then just pass that URL to Homebrew

require 'net/http'
require 'json'
require 'uri'

cask 'audacity' do
    version '2.3.3'
    sha256 '43db4d502086257ca377326f9621a343149faac6d3334424b20a3b5caceadda8'

  # Current official URL as proposed on http://www.audacityteam.org/download/mac/
  # must be parsed to extract temporary url embedded in iframe
  def get_audacity_url
    fosshub_response = nil
    uri = URI("https://api.fosshub.com/download/")
    Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https') do |http|
      request = Net::HTTP::Post.new(uri, 'Content-Type' => 'application/json', 'User-Agent' => 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36')
      request.body = {
        "fileName" => "audacity-macos-2.3.3.dmg",
        "projectId" => "5b7eee97e8058c20a7bbfcf4",
        "projectUri" => "Audacity.html",
        "releaseId" => "5dd7e00e1d5d8e08348e2444",
        "source" => "CF"
      }.to_json
      response = http.request request # Net::HTTPResponse object
      fosshub_response = JSON.parse(response.body)
      end
    return fosshub_response['data']['url']
  end
  url get_audacity_url
  name 'Audacity'
  homepage 'http://audacityteam.org'
  
  app 'Audacity.app'
  
  zap delete: '~/Library/Application Support/audacity'
end

could this not be added to brew cask?

Fosshub isn’t very keen on direct downloads so they decided to not include it in brew cask anymore. See Homebrew/homebrew-cask#12972

why should the brew cask repository care about limitations fosshub has?

See the comment from @vitorgalvao here: Homebrew/homebrew-cask#27517
That’s their reason.