Time.rfc3339 accepts a UTC offset without a colon

[yahonda]

Follow-up to #73 / #74: Time.rfc3339 on master (tested at 95ab5fa) accepts a numeric UTC offset written without the colon separator, which Section 5.6 of RFC 3339 does not allow.

Steps to reproduce

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"
  gem "time", github: "ruby/time"
end

require "time"
require "date"

p Time.rfc3339("1999-12-31T19:00:00-0400")
p DateTime.rfc3339("1999-12-31T19:00:00-0400")

Expected behavior

Both calls raise. The ABNF in Section 5.6 (https://datatracker.ietf.org/doc/html/rfc3339#section-5.6) reads:

time-numoffset  = ("+" / "-") time-hour ":" time-minute

The colon between the hour and the minute of a numeric offset is not optional.

Actual behavior

1999-12-31 19:00:00 -0400
repro.rb:12:in 'DateTime.rfc3339': invalid date (Date::Error)

Time.rfc3339 accepts the string; DateTime.rfc3339 rejects it. The colon is optional in the offset group of the pattern:

time/lib/time.rb

Line 663 in 95ab5fa

(Z|[+-]\d\d:?\d\d)

References

• DateTime.rfc3339 parses via Date._rfc3339: https://github.com/ruby/date/blob/3481cf7ce9149011f1a4eb2bfffc2a0b44c8bf07/ext/date/date_core.c#L8701-L8722
• Active Support's Time.rfc3339 is a thin wrapper around the same Date._rfc3339, so Rails applications observe the same rejection: https://github.com/rails/rails/blob/fa8f0812160665bff083a089d2bb2fc1817ea03e/activesupport/lib/active_support/core_ext/time/calculations.rb#L69-L83

[jeremyevans]

Thank you for the report. I'll work on a pull request to fix this.