gettag.js

      // Grab the ComType tag
      const getTag = (product, tag) =>
        product.Tags
          .split(',')
          .find(t => t.startsWith(`${tag}=`))
          .split('=')[1]

      const keyMatches = key => compose(equals(Just(key)))(head)
      const getTagf = (product, tag) =>
        compose
          (fromMaybe(Just('')))   // or provide an empty string
          (tail)                  // Take the value
          (find(keyMatches(tag))) // Find pair with matching key
          (map(splitOn('=')))     // Split KVPs
          (splitOn(','))          // Split CSVs
          (toMaybe(product.Tags)) // Take maybe null string of CSV KVPs