Logo: Relish

  1. Sign in

Project: Vcr 2.9.3

Freezing Time

When dealing with an HTTP API that includes time-based compontents
in the request (e.g. for signed S3 requests), it can be useful
on playback to freeze time to what it originally was when the
cassette was recorded so that the request is always the same
each time your test is run.

While VCR doesn't directly support time freezing, it does
expose VCR::Cassette#originally_recorded_at, which you can
easily use with a library like
timecop
to freeze time.

Note: VCR::Cassette#originally_recorded_at will return nil
when the cassette is recording for the first time, so you'll
probably want to use an expression like
cassette.originally_recorded_at || Time.now so that it
will work when recording or when playing back.

Scenarios
Previously recorded responses are replayed
Given
a previously recorded cassette file "cassettes/example.yml" with:
--- 
http_interactions: 
- request: 
    method: get
    uri: http://example.com/events/since/2013-09-23T17:00:30Z
    body: 
      encoding: UTF-8
      string: ""
    headers: {}
  response: 
    status: 
      code: 200
      message: OK
    headers: 
      Content-Length: 
      - "20"
    body: 
      encoding: UTF-8
      string: Some Event
    http_version: "1.1"
  recorded_at: Mon, 23 Sep 2013 17:00:30 GMT
recorded_with: VCR 2.0.0
Given
a file named "freeze_time.rb" with:
require 'time'
require 'timecop'
require 'vcr'

VCR.configure do |vcr|
  vcr.cassette_library_dir = 'cassettes'
  vcr.hook_into :webmock
end

VCR.use_cassette('example') do |cassette|
  Timecop.freeze(cassette.originally_recorded_at || Time.now) do
    path = "/events/since/#{Time.now.getutc.iso8601}"
    response = Net::HTTP.get_response('example.com', path)
    puts "Response: #{response.body}"
  end
end
When
I run ruby freeze_time.rb
Then
it should pass with "Response: Some Event"

Last published about 5 years ago by myronmarston.