comparing dates and times in RSpec

_README.md

What is this?

How do you compare date/times in RSpec?

If you do this

expect(Time.now.to_i).to eq Time.new(2014, 4, 2).to_i

and you usually use more human format of expressing time, than just spitting out the miliseconds since January 1, 1970 - I've got some bad news for you.

Have you ever wondered what does this mean?

1) time comparison doesn't pass for different time
     Failure/Error: expect(Time.now.to_i).to eq Time.new(2014, 4, 2).to_i
       
       expected: 1396389600
            got: 1396430562

Yes, me too - these miliseconds are not that expressive...

With this gist, that will change into:

  1) time comparison doesn't pass for different time
     Failure/Error: expect(Time.now).to be_the_same_time_as Time.new(2014, 4, 2)
       expected 2014-04-02 11:28:41 +0200 to be the same time as 2014-04-02 00:00:00 +0200

Much nicer, right?

Don't believe me?

Run this

bash < <( curl -fsSL https://gist.githubusercontent.com/shime/9930893/raw/try.sh )

Trust me, I'm just a random guy from the interwebz!

example_spec.rb

RSpec::Matchers.define :be_the_same_time_as do |expected|
  match do |actual|
    expect(expected.strftime("%d-%m-%Y %H:%M:%S")).to eq(actual.strftime("%d-%m-%Y %H:%M:%S"))
  end
end

describe "time comparison" do
  it "passes for equal dates" do
    expect(Time.new(2014, 4, 2)).to be_the_same_time_as Time.new(2014, 4, 2)
  end

  it "passes for equal time" do
    expect(Time.now).to be_the_same_time_as Time.now
  end

  it "doesn't pass for different time" do
    expect(Time.now).to_not be_the_same_time_as Time.new(2014, 4, 2)
  end
end

try.sh

curl -fsSL https://gist.githubusercontent.com/shime/9930893/raw/example_spec.rb > /tmp/example_spec.rb
rspec -c /tmp/example_spec.rb