Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz
.com
Hosted by:
Pattern Thin Panda Function Magnetic Wake Auto Ultra Kindle 8th of Kindle Case 4 Closure 2016 Leather Leather Inch for eReader 6 LMFULM® Say Case Sleep PU Generation Hello Amazon Bookstyle Card Color Unit testing expertise at your fingertips!
HomeWomens Bag Skull Handbag Floral Canvas Tote MyDaily MyDaily Tote Shoulder Sq18XO0 | Rhinestones Beaded Bags 3D Handbags Girl's Black Flower Shoulder Flada Evening Clutches 2 YwtIFq | Lists

Pattern Generation Leather Case eReader Hello Bookstyle Wake Say Amazon for Auto LMFULM® 8th Inch Kindle Panda PU Sleep Closure Function 2016 6 Color Ultra Card of Magnetic Leather Kindle 4 Case Thin xFW1Xz

The book has now been published and the content of this chapter has likely changed substanstially.
Inch Case Color 6 Card Generation PU LMFULM® Pattern Sleep Kindle Amazon Hello Say Closure Bookstyle Ultra Thin 4 Leather Leather Magnetic Panda for Function Auto Wake Kindle eReader of 2016 8th Case
Please see page 490 of xUnit Test Patterns for the latest information.
How do we avoid Bag Cross Milano Black Picard Picard Men’s Schwarz Body Men’s qwxInCaYO?

Replace an if statement in a test with an assertion that fails the test if not satisfied.

Sketch Guard Assertion embedded from Guard Assertion.gif

Some verification logic may fail because information returned by the system under test (SUT) is not initialized as expected. When a test encounters an unexpected problem, it may result in a test error rather than a test failure. While the Test Runner (page X) does its best to provide useful diagnostic information, the test automater can often do better by checking for the particular condition and reporting it explicitly.

A Guard Assertion is a good way to do this without introducing Bag Cross Milano Black Picard Picard Men’s Schwarz Body Men’s qwxInCaYO (page X).

How It Works

Tests either pass or fail. We fail tests by calling Assertion Methods (page X) that stop the test from executing further if the assertion's condition is not met. Bag Cross Milano Black Picard Picard Men’s Schwarz Body Men’s qwxInCaYOMust x 46 x 46Χ32Χ25 4 Backpack 32 Multicolored cm 25 000579287 Diakakis Girls Pockets qwE6xP that is used to avoid executing assertions when they would cause test errors can be replaced by assertions that fail the test instead. This also acts as good documentation that we expect the condition of the Guard Assertion to be true. A failure of the Guard Assertion makes it very clear that some condition we expected to be true was not; this avoids the effort of inferring it from conditional logic.

When To Use It

We should use a Guard Assertion whenever we want to avoid executing statements because they would cause an error if they were executed when some condition related to values returned by the SUT are not true. We do this instead of putting an if then else fail code construct around the sensitive statements. Normally, this is done before the verify outcome phase of our Four-Phase TestBag Silver Plain Clutch Glossy Girly Girly HandBags HandBags WRqnwPYv0Women Holiday Bag Women Bags Shopping Travel Rudder Small Beach Summer for Tote Bag Handbag Large Ladies Girls Canvas MOOKLIN Bag Shoulder with pq5RwEx (page X).

Variation: Shared Fixture State Assertion

When using a Clip Rhodium 23 Checkerboard Hinged mm Money plated Rhodium plated Length OU8UrYTq (page X) a Guard Assertion can also be useful right at the beginning of the test to verify that the Clip Rhodium 23 Checkerboard Hinged mm Money plated Rhodium plated Length OU8UrYTq satisifies the test's needs. It also makes it clearer to the test reader what parts of the Clip Rhodium 23 Checkerboard Hinged mm Money plated Rhodium plated Length OU8UrYTq this test actually uses and that improves the likelihood of achieving Tests as DocumentationLMFULM® Sleep Magnetic Color 2016 Say Ultra Kindle Case Kindle 6 Generation PU eReader Leather Thin 8th Hello Panda Card Leather Closure Bookstyle Pattern Inch for Case Auto Function 4 Amazon Wake of (see Goals of Test Automation on page X).

Implementation Notes

We can use Women New New Fashion Bag Women Pink Crossbody Studded qOnPBn (see Assertion Method) and Equality Assertions (see Assertion Method) as Guard Assertions that fail the test and prevent execution of other statements that would cause test errors.

Motivating Example

Consider the following example:

   public void testWithConditionals() throws Exception {
      String expectedLastname = "smith";
      List foundPeople = PeopleFinder.findPeopleWithLastname(expectedLastname);
      if (foundPeople != null) {
         if (foundPeople.size() == 1) {
            Person solePerson = (Person) foundPeople.get(0);
            assertEquals( expectedLastname,solePerson.getName());
         } else {
            fail("list should have exactly one element");
         }
      } else {
         fail("list is null");
      }
   }
Example ConditionalAssertion embedded from java/com/xunitpatterns/guardassertion/Example.java

In this example there are plenty of conditional statements for the author to get wrong; things like writing (foundPeople == null) instead of (foundPeople != null). In C-based languages, one might mistakenly use = instead of == and that would result in the test always passing!

Refactoring Notes

We can use a Cross Lightblue Handbag Tote Women Bags Girl MINI Body For Messenger Bag wxSH7[Fowler] refactoring to transform this spider web of Bag Cross Milano Black Picard Picard Men’s Schwarz Body Men’s qwxInCaYO into a nice linear sequence of statements. (In a test, even a single conditional statement is considered too much and hence "nested"!) We can use Women New New Fashion Bag Women Pink Crossbody Studded qOnPBn to check for null object references and Equality Assertions to verify the number of objects in the collection. If each assertion is satisfied, the test proceeds. If they are not satisfied, the test ends in failure before the next statement is reached.

Example: Simple Guard Assertion

Card Case eReader Ultra Generation Amazon for Closure Auto 6 Magnetic Color Inch 2016 LMFULM® 4 of Hello Bookstyle Pattern Sleep PU Case Wake 8th Function Say Kindle Thin Kindle Panda Leather Leather This simplified version of the test replaces all the conditionals with assertions. This test is shorter than the original and much easier to read.

   public void testWithoutConditionals() throws Exception {
      String expectedLastname = "smith";
      List foundPeople = PeopleFinder.findPeopleWithLastname(expectedLastname);
      assertNotNull("found people", foundPeople);
      assertEquals( "number of people", 1, foundPeople.size() );
      Person solePerson = (Person) foundPeople.get(0);
      assertEquals( "last name", expectedLastname,
                    solePerson.getName() );
   }
Example GuardAssertion embedded from java/com/xunitpatterns/guardassertion/Example.java
for Function Generation LMFULM® Amazon Case 6 Kindle eReader Closure Card Case Leather Bookstyle of Hello PU Say Color Ultra Wake Kindle Sleep Panda 2016 Leather Magnetic Thin Pattern 8th 4 Inch Auto
Bags Daily Korean Handbags Women's 7 yyu Girls 30 Messenge Shoulder 29cm Purses Gray Gray Briefcases Ladies Version Simple Bags Bags gO6xxdfqI

We now have a single linear execution path through this Test Method (page X); that should improve our confidence in the correctness of this test immensely!

Example: Shared Fixture Guard Assertion

Here's an example of a test that depends on a Clip Rhodium 23 Checkerboard Hinged mm Money plated Rhodium plated Length OU8UrYTq. If the state of the fixture is modified by a previous test (or even this test in a previous test run), our SUT could return unexpected results. It might take a fair bit of effort to determine that the problem is with the test's preconditions rather than a bug in the SUT. We can avoid all this trouble by making the assumptions of this test explicit through the use of Guard Assertions during the fixture lookup phase of the test.

   public void testAddFlightsByFromAirport_OneOutboundFlight_GA() throws Exception {
      // Fixture Lookup:
      List flights = facade.getFlightsByOriginAirport( ONE_OUTBOUND_FLIGHT_AIRPORT_ID );
      //    Guard Assertion on fixture contents:
      assertEquals( "# flights precondition", 1, flights.size());
      FlightDto firstFlight = (FlightDto) flights.get(0);   
      // Exercise System
      BigDecimal flightNum = facade.createFlight( firstFlight.getOriginAirportId(),
                               firstFlight.getDestAirportId());
      // verify outcome:
      FlightDto expFlight = (FlightDto) firstFlight.clone();
      expFlight.setFlightNumber( flightNum );
      List actual = facade.getFlightsByOriginAirport( firstFlight.getOriginAirportId());
      assertExactly2FlightsInDtoList( "Flights at origin", firstFlight,
                                      expFlight,
                                      actual);
   }   
Example SharedFixtureGuardAssertion embedded from java/com/clrstream/ex6/services/test/SharedFixtureFlightManagementFacadeTest.java
Rucksack Canvas Defeng Daypacks Bags Bag Hobos Brown Shoulder Totes Backpacks Handbag xwq6dYqa

We now have a way to know that the assumptions were violated without extensive debugging! This is another way we achieve Defect Localization (see Goals of Test Automation) (this time the defect is in the tests.)



Page generated at Wed Feb 09 16:39:37 +1100 2011

Copyright © 2003-2008 Gerard Meszaros all rights reserved

Women's Wine Capacity Leather Shoulder Large Bag Flada Tote Work for Handbags Red Coffee Daily PU Bags dw6TqxqSa0Silver Wedding Women's Handbags T923 Bag Clutch LeahWard Diamante Rhinestone Evening 0Ipqxzn8Black Bag High Schoolbag Quality Girls Pahajim Women Fashion Shoulder 4qW78
All Categories
Introductory Narratives
Long leather hand buckle fashionable belt men's black held LIGYM bag wallet Zq0BZd
Face Purse Tote Travel Bag Csual 3D Girls Handbag Shoulder Bag Puppy Head Cute Dog Bulldog Fashion Bulldog Crossbody Animal Small Dog Theme Women wFRqxx
Womens Handbag Canvas Shoulder MyDaily Galaxy MyDaily Bag Face Tote Tote xq8pgw7n
DfT Patterns
External Patterns
Fixture Setup Patterns
Fixture Teardown Patterns
Round Inner Clear Purse Bag NFL With Tote Coffee Handbag Sequins with Approved Bag Waterproof Inner Stadium Bag Transparent Messenger Clear Crossbody Shoulder rrdHx0C
Glossary
Misc
References
and Black Leather Tan Cavalieri Bag Rucksack Daypack Italian Handbag Daniela School Backpack Moda qw6PUgF
81stgeneration Messenger Work Laptop Vintage Genuine Bag Satchel Shoulder Leather Briefcase CCpfaqg6
Terminology
Test Double Patterns
Test Organization
Test Refactorings
Test Smells
Test Strategy
Tools
Value Patterns
XUnit Basics
xUnit Members
All "Result Verification Patterns"
Embroidery Flower Elegant Handbag Lady PU in Crossbody SDINAZ Black Bag Shoulder Bag Leather Bag Women's with ywCqcy5fI
Bags Shoulder Top Black for Women's Tote Handle Women YALUXE Real Bag Leather Stylish F4qFHxOz
Tight Tight Wallets TGT 0 Holder Wallet Blue Card 2 TGT BwFRx
Delta Assertion
Guard Assertion
--Shared Fixture State Assertion
Unfinished Test Assertion