Checking if market is a valid ISO 3166-1 alpha-2 country code needs to be negated

[karjamatti]

These functions

get_show()
get_shows()
get_show_episodes()
get_album()
get_albums()
get_album_tracks()
get_my_saved_albums()

that have the following check:

if (str_detect(market, '^[[:alpha:]]{2}$')) {
            stop('"market" must be an ISO 3166-1 alpha-2 country code')
}

Where the logical test needs to be negated, like so:

if (!str_detect(market, '^[[:alpha:]]{2}$')) {
            stop('"market" must be an ISO 3166-1 alpha-2 country code')
}

Since it's now raising an error when market is indeed in the correct format.

The negated version of the check s is already correctly implemented in the following functions:

get_artist_albums()
get_artist_top_tracks()

Moreover, the search_spotify() ad validate_market() functions use a different approach, which I like even better tbh:

   if (!is.null(market)) {
        assertthat::assert_that(
            str_detect(market, '^[[:alpha:]]{2}$'),
            msg = "The parameter 'market' must be an ISO 3166-1 alpha-2 country code."
        )
    }