使用RSpec时Rails DateTime中的随机空间？

Question

I have a method in my Event model:

  def when
    self.starts_at.strftime("%a %b %e @ %-I:%M")
  end

which outputs correctly in the rails console or on a webpage.

However, doing an rspec test like this:

  it "has simple date display" do
    game = FactoryGirl.build(:event, starts_at: DateTime.parse("1/1/2014 3:30pm"))
    game.when.should == "Wed Jan 1 @ 3:30"
  end

fails, because of:

1) Event has simple date display
     Failure/Error: event.when.should == "Wed Jan 1 @ 3:30"
       expected: "Wed Jan 1 @ 3:30"
            got: "Wed Jan  1 @ 3:30" (using ==)

Why is there a random space in my formatted DateTime? Shouldn't the same DateTime code be loaded/running for tests and console?

Answer 1

You're using the %e format directive, which is for the blank-padded day of month. It sounds like you want the unpadded day of the month directive, which is %-d . Here are the docs .

Answer 2

The reason your test is failing is because the %e directives in strftime is:

%e - Day of the month, blank-padded ( 1..31)

So the statement DateTime.parse("1/1/2014 3:30pm").strftime("%a %b %e @ %-I:%M") yields Wed Jan 1 @ 3:30 (with extra space prepended for days between 1 through 9).

You could use %d directive instead which gives day of month, zero-padded. Eg

# Event model
def when
  self.starts_at.strftime("%a %b %d @ %-I:%M")
end

Then in your spec:

it "has simple date display" do
  game = FactoryGirl.build(:event, starts_at: DateTime.parse("1/1/2014 3:30pm"))
  game.when.should == "Wed Jan 01 @ 3:30"
end