time.rb

require "minitest/autorun"
require "timecop"

describe "Parsing time in a time zone" do
  describe "on current day" do
    it "returns the proper offset" do
      Timecop.travel Time.new(2016, 3, 9) do
        time_string = "03/09/2016 10:00 AM America/Chicago"
        format_string = "%m/%d/%Y %I:%M %p %Z"

        parsed_time = Time.strptime(time_string, format_string)
        expected_time = Time.new(2016, 3, 9, 10, 0, 0, "-06:00")

        # fails - parsed time is at "-05:00" offset, which is my current, local
        # timezone (Eastern Standard)
        parsed_time.must_equal expected_time
      end
    end

    it "returns the proper offset when explicitly passing offset" do
      Timecop.travel Time.new(2016, 3, 9) do
        time_string = "03/09/2016 10:00 AM -0600"
        format_string = "%m/%d/%Y %I:%M %p %z"

        parsed_time = Time.strptime(time_string, format_string)
        expected_time = Time.new(2016, 3, 9, 10, 0, 0, "-06:00")

        parsed_time.must_equal expected_time
      end
    end

    it "returns the proper offset when explicitly passing abbreviation with
        daylight savings time indication" do
      Timecop.travel Time.new(2016, 3, 9) do
        time_string = "03/09/2016 10:00 AM CST"
        format_string = "%m/%d/%Y %I:%M %p %Z"

        parsed_time = Time.strptime(time_string, format_string)
        expected_time = Time.new(2016, 3, 9, 10, 0, 0, "-06:00")

        parsed_time.must_equal expected_time
      end
    end
  end
end