How can I stub a method only on the first call, and in the second one it should behave as expected?
I have the following method:
def method
do_stuff
rescue => MyException
sleep rand
retry
end
I want to the first call of do_stuff
to raise MyException
, but in the second call, behaves normally. I need to achieve this to test my rescue
block without getting an infinite loop.
Is there a way to achieve this?
You can pass a block to a stub that will be invoked when the stub is called. You can then perform the unstub in there, in addition to doing whatever you need to.
class Foo
def initialize
@calls = 0
end
def be_persistent
begin
increment
rescue
retry
end
end
def increment
@calls += 1
end
end
describe "Stub once" do
let(:f) { Foo.new }
before {
f.stub(:increment) { f.unstub(:increment); raise "boom" }
}
it "should only stub once" do
f.be_persistent.should == 1
end
end
Seems to work nicely here.
$ rspec stub.rb -f doc
Stub once
should only stub once
Finished in 0.00058 seconds
1 example, 0 failures
Alternately, you could just track the number of calls and return different results for the stub based on the call count:
describe "Stub once" do
let(:f) { Foo.new }
it "should return different things when re-called" do
call_count = 0
f.should_receive(:increment).twice {
if (call_count += 1) == 1
raise "boom"
else
"success!"
end
}
f.be_persistent.should == "success!"
end
end