rspec users - Apr 2009 - How to approach testing automated processing

I have a requirement to fetch a data feed from our central bank and set
a variety of currency exchange rates from that feed. My question is how
does one approach behavioural driven design with autonomous automated
processing? What I started with is this:

Feature: Automatically Retrieve and Store Foreign Currency Exchange
Rates
  In order to accurately set foreign currency exchange rates daily
  The automated system
  Should automatically retrieve and store central bank exchange rates
  To Reduce Costs and Protect Revenue

  Scenario:  Retrieve Exchange Rates from the Bank of Canada RSS feed
    Given an RSS feed
"http://www.bankofcanada.ca/rss/fx/noon/fx-noon-all.xml"
    When I access the RSS feed
    Then I should see "Bank of Canada: Noon Foreign Exchange Rates"
      And I should see today''s date in "yyyy-mm-dd" format

Now, while I have a pretty good idea how I am going to accomplish this,
via cron and a standalone Ruby script, I am sort of perplexed about how
I should construct the feature step definitions and how I would test
this.  I figure I just have to take as given that cron works because
that is not my code.  But how best to test that the rest works?

The automatic script will contain not much more than a list of the
external libraries a call to a methods in class that I have named
ForexCASource, loop through and map the returned array of hashes to the
corresponding CurrencyExchangeRate attributes of a new row, call #save!
and repeat until finished.

How have others handled this sort of thing?
-- 
Posted via http://www.ruby-forum.com/.

On Sat, Apr 18, 2009 at 7:02 PM, James Byrne <lists at ruby-forum.com>
wrote:
> I have a requirement to fetch a data feed from our central bank and set
> a variety of currency exchange rates from that feed. My question is how
> does one approach behavioural driven design with autonomous automated
> processing? What I started with is this:
>
> Feature: Automatically Retrieve and Store Foreign Currency Exchange
> Rates
> ?In order to accurately set foreign currency exchange rates daily
> ?The automated system
> ?Should automatically retrieve and store central bank exchange rates
> ?To Reduce Costs and Protect Revenue
>
> ?Scenario: ?Retrieve Exchange Rates from the Bank of Canada RSS feed
> ? ?Given an RSS feed
> "http://www.bankofcanada.ca/rss/fx/noon/fx-noon-all.xml"
> ? ?When I access the RSS feed
> ? ?Then I should see "Bank of Canada: Noon Foreign Exchange
Rates"
> ? ? ?And I should see today''s date in "yyyy-mm-dd"
format
>
> Now, while I have a pretty good idea how I am going to accomplish this,
> via cron and a standalone Ruby script, I am sort of perplexed about how
> I should construct the feature step definitions and how I would test
> this. ?I figure I just have to take as given that cron works because
> that is not my code. ?But how best to test that the rest works?
I would probably approach it this way.

- Make a local copy of the RSS feed you''re expecting to import
- Write a feature which specifies the command you want to run. This
command would be the same command you used with cron. I would make it
take a path or URI as an argument.
- Have the feature ensure the the right number of records were created
based on your local copy of the feed
- Drop down to RSpec and re-use the local copy of the feed to ensure
that all of the little details (if you have little details) are
properly imported

When that is done I would probably write a feature that actually hits
the Bank of Canada''s site, and I would set this up to run on
continuous integration only. Maybe using Cucumber tags or a directory
structure, and a new rake task to help isolate CI only features from
the rest.

Now when I run features locally I can be very very confident
everything works, and if CI fails one day because the Bank of Canada
changed their format, now you know you need to pull over a new copy of
the feed locally, and update your local features and specs.

That general approach has worked well in the past (and I say past
because before Cucumber existed I still wrote features/scenarios with
StoryRunner, and before that my team had tooled its own ad hoc story
runner).

HTH
>
> The automatic script will contain not much more than a list of the
> external libraries a call to a methods in class that I have named
> ForexCASource, loop through and map the returned array of hashes to the
> corresponding CurrencyExchangeRate attributes of a new row, call #save!
> and repeat until finished.
>
> How have others handled this sort of thing?
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> rspec-users mailing list
> rspec-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/rspec-users
>


-- 
Zach Dennis
http://www.continuousthinking.com
http://www.mutuallyhuman.com

Zach Dennis wrote:
> On Sat, Apr 18, 2009 at 7:02 PM, James Byrne <lists at
ruby-forum.com> wrote:
>   
>> I have a requirement to fetch a data feed from our central bank and set
>> a variety of currency exchange rates from that feed. My question is how
>> does one approach behavioural driven design with autonomous automated
>> processing? What I started with is this:
>>
>> Feature: Automatically Retrieve and Store Foreign Currency Exchange
>> Rates
>>  In order to accurately set foreign currency exchange rates daily
>>  The automated system
>>  Should automatically retrieve and store central bank exchange rates
>>  To Reduce Costs and Protect Revenue
>>
>>  Scenario:  Retrieve Exchange Rates from the Bank of Canada RSS feed
>>    Given an RSS feed
>> "http://www.bankofcanada.ca/rss/fx/noon/fx-noon-all.xml"
>>    When I access the RSS feed
>>    Then I should see "Bank of Canada: Noon Foreign Exchange
Rates"
>>      And I should see today''s date in "yyyy-mm-dd"
format
>>
>> Now, while I have a pretty good idea how I am going to accomplish this,
>> via cron and a standalone Ruby script, I am sort of perplexed about how
>> I should construct the feature step definitions and how I would test
>> this.  I figure I just have to take as given that cron works because
>> that is not my code.  But how best to test that the rest works?
>>     
>
> I would probably approach it this way.
>
> - Make a local copy of the RSS feed you''re expecting to import
> - Write a feature which specifies the command you want to run. This
> command would be the same command you used with cron. I would make it
> take a path or URI as an argument.
> - Have the feature ensure the the right number of records were created
> based on your local copy of the feed
> - Drop down to RSpec and re-use the local copy of the feed to ensure
> that all of the little details (if you have little details) are
> properly imported
>   
+1  I have done this in the past and it worked well.  If you haven''t 
already checkout the fakeweb library for stubbing out the calls to 
Net::HTTP:

http://github.com/chrisk/fakeweb

-Ben
> When that is done I would probably write a feature that actually hits
> the Bank of Canada''s site, and I would set this up to run on
> continuous integration only. Maybe using Cucumber tags or a directory
> structure, and a new rake task to help isolate CI only features from
> the rest.
>
> Now when I run features locally I can be very very confident
> everything works, and if CI fails one day because the Bank of Canada
> changed their format, now you know you need to pull over a new copy of
> the feed locally, and update your local features and specs.
>
> That general approach has worked well in the past (and I say past
> because before Cucumber existed I still wrote features/scenarios with
> StoryRunner, and before that my team had tooled its own ad hoc story
> runner).
>
> HTH
>
>   
>> The automatic script will contain not much more than a list of the
>> external libraries a call to a methods in class that I have named
>> ForexCASource, loop through and map the returned array of hashes to the
>> corresponding CurrencyExchangeRate attributes of a new row, call #save!
>> and repeat until finished.
>>
>> How have others handled this sort of thing?
>> --
>> Posted via http://www.ruby-forum.com/.
>> _______________________________________________
>> rspec-users mailing list
>> rspec-users at rubyforge.org
>> http://rubyforge.org/mailman/listinfo/rspec-users
>>
>>     
>
>
>
>

Zach Dennis wrote:
> On Sat, Apr 18, 2009 at 7:02 PM, James Byrne <lists at
ruby-forum.com>
> wrote:
>> ?To Reduce Costs and Protect Revenue
>> I should construct the feature step definitions and how I would test
>> this. ?I figure I just have to take as given that cron works because
>> that is not my code. ?But how best to test that the rest works?
> 
> I would probably approach it this way.
> 
> - Make a local copy of the RSS feed you''re expecting to import
Yup, done that. Mainly because I now have fixed data to test against but 
in the exact format that the feed supplies.
> - Write a feature which specifies the command you want to run. This
> command would be the same command you used with cron. I would make it
> take a path or URI as an argument.
Ahh. I had not thought of that.
> - Have the feature ensure the the right number of records were created
> based on your local copy of the feed
K.
> - Drop down to RSpec and re-use the local copy of the feed to ensure
> that all of the little details (if you have little details) are
> properly imported
> 
> When that is done ... 
Will do.
> That general approach has worked well in the past (and I say past
> because before Cucumber existed I still wrote features/scenarios with
> StoryRunner, and before that my team had tooled its own ad hoc story
> runner).
>
> HTH
> 
It certainly does. Thanks.


-- 
Posted via http://www.ruby-forum.com/.