Sometimes I see code like this:
class Alarm
attr_reader :at
def initialize(at: )
@at = at
end
def snooze
# ...
end
end
RSpec.describe Alarm do
describe "#at" do
it "returns alarm time" do
time = Time.now
alarm = described_class.new(at: time)
expect(alarm.at).to eq time
end
end
end
This is a useless test. First, we are testing a standard library, a thing that already has its own tests. Why does it need more tests?
Secondly, we are testing trivial behavior.
Third, we will indirectly check the getter (Alarm#at) in other tests:
describe "#snooze" do
it "snoozes alarm for nine minutes" do
# ...
expect { alarm.snooze }.to change { alarm.at }.by(9.minutes)
end
end
P. S. PROTIP: if the attr_reader is only needed by the object itself, it'd better to make it private:
private
attr_reader :repeat
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