Replace repeated timestamp with variable in tests

Question

I have couple hundred tests and I work with date/time a lot. In some tests, I aim for output format, elsewhere, I check date ranges. Therefore, my tests have lots of these:

FactoryGirl.create(:foo, ended_at: Time.zone.local(2014, 5, 5, 22, 15))

I thought, maybe there's a shortcut to these, since in some test files, I only work with few timestamps.

FactoryGirl.create(:foo, ended_at: may_5_22_15)

Where may_5_22_15 would be defined in method or using let.

Is this a good way to go?

Update: More context (thanks @Snowman for pointing out).

Motivation for this is to improve readability of testsuite. It makes it easier to me to read "Foo ended at May 5th by 22:15" rather than parsing a bunch of numbers in Time constructor.

The model has bunch of date/time attributes (ended_at, started_at, closed_at...) and the more specs I write, the more Time constructors I use and re-use. So I thought maybe I could do something like this:

let(:may_5_22_15) { Time.zone.local(2014, 5, 5, 22, 15) }

What I'd like to know is whether this is a good practice or not, in terms of test suite maintenance, readability or if there are any reasons why not to do it.

What problem are you trying to solve? What is the perceived benefit of making this change? — , Feb 04 '15 at 22:24
@Snowman - readability - I'm just thinking how to make the tests read easier. — rdamborsky, Feb 04 '15 at 22:34

score 1 · Answer 1 · answered Feb 06 '15 at 15:37

Named constants are often a better idea than magic numbers. In this context, however, there's not a lot of magic involved. On the other hand, in some languages, the time-value constructor uses a zero-ordinal value for only some of its values (e.g., JavaScript's Date()'s month number), or have illogical behavior such as accepting out-of-range values as non-integral multiples of the next-higher order (again, JavaScript's Date()). In such environments, a named constant for a timestamp makes excellent sense.

score 0 · Answer 2 · edited May 23 '17 at 12:40

0

I am not sure where the ended_at method is defined, but there is no reason why you could not extend it so that it would take whatever kind of string input you want using Time.parse

edited May 23 '17 at 12:40

Community

1

answered Feb 05 '15 at 23:13

Dmitri

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Малъ Скрылевъ · Answer 3 · 2015-02-09T18:19:53.070

Just create a specific factory or use default with redefinable value ended_at, as follows:

factory :foo do
   ended_at { |foo| foo.ended_at || Time.zone.local(2014, 5, 5, 22, 15) }
end

or with ignore block:

factory :foo do
   ignore do
      ended_at { Time.zone.local(2014, 5, 5, 22, 15) }
   end

   after :build do |foo, evaluator|
      foo.ended_at = evaluator.ended_at
   end
end

or pass some usual symbol with encoded datetime in its name:

factory :foo do
   ignore do
      ended_at { '' }
   end

   after :build do |foo, evaluator|
      foo.ended_at = Time.strptime(evaluator.ended_at, '%b_%e_%k_%M')
   end
end

Replace repeated timestamp with variable in tests

3 Answers3