Slides and follow-up material from all CAST presentations are available through the CAST 2007 wiki.
All the presentations from the conference will be posted on YouTube Google Channel within a New York minute after the speaker leaves the podium (well, maybe 72 New York minutes). We look forward to seeing you at the conference.
When a method is long and complex, it is harder to test. You can make it easier by extracting methods: finding pieces of code in existing, complex methods (or functions) that can be replaced with method calls (or function calls). Consider the following complicated method:
def GetTestResults(self): # Check if results have been cached. results = cache.get('test_results', None) if results is None: # No results in the cache, so check the database. results = db.FetchResults(SQL_SELECT_TEST_RESULTS) # Count passing and failing tests. num_passing = len([r for r in results if r['outcome'] == 'pass']) num_failing = len(results) - num_passing return num_passing, num_failing
This method is difficult to test because it not only relies on a database, but also on a cache. In addition, it performs some post processing of the retrieved results. The first hint that this method could use refactoring is the abundance of comments. Extracting sections of code into well-named methods reduces the original method's complexity. When complexity is reduced, comments often become unnecessary. For example, consider the following:
def GetTestResults(self): results = self._GetTestResultsFromCache() if results is None: results = self._GetTestResultsFromDatabase() return self._CountPassFail(results) def _GetTestResultsFromCache(self): return cache.get('test_results', None) def _GetTestResultsFromDatabase(self): return db.FetchResults(SQL_SELECT_TEST_RESULTS) def _CountPassFail(self, results): num_passing = len([r for r in results if r['outcome'] == 'pass']) num_failing = len(results) - num_passing return num_passing, num_failing
Now, tests can focus on each individual piece of the original method by testing each extracted method. This has the added benefit of making the code more readable and easier to maintain.
(Note: Method extraction can be done for you automatically in Python by the open-source refactoring browser BicycleRepairMan, and in Java by several IDEs, including IntelliJ IDEA and Eclipse.)
posted by Allen Hutchison, Engineering Manager A few months ago we announced that we would be holding a Google Test Automation Conference in New York City on August 23-24. Today, I'm happy to tell you that we've finalized the speaker list and have opened the attendee registration process.The conference is completely free; however, because we have room for only 150 people, everyone who wishes to attend must apply and be accepted. You can apply to attend via this link, and we'll let you know by June 15 if your application has been accepted.
At last year's conference, we found that the informal hallway discussions were tremendously valuable to everyone who came, and we would like to continue that custom. Therefore, the main point in the application process is to tell us how you can contribute to the conversation and what you would like to learn from the conference.
To get you started, here is what our speakers will be talking about:
