Google Testing Blog: July 2014

Testing on the Toilet: Don't Put Logic in Tests

Thursday, July 31, 2014

by Erik Kuefler
This article was adapted from a Google Testing on the Toilet (TotT) episode. You can download a printer-friendly version of this TotT episode and post it in your office. Programming languages give us a lot of expressive power.this flexibility comes at the cost of increased complexitysimplicity is more important than flexibility in testsTests can avoid complexity by stating their inputs and outputs directly rather than computing themDoes this test look correct to you? @Test public void shouldNavigateToPhotosPage() { String baseUrl = "http://plus.google.com/"; Navigator nav = new Navigator(baseUrl); nav.goToPhotosPage(); assertEquals(baseUrl + "/u/0/photos", nav.getCurrentUrl()); }what happens if we simplify the test by inlining the variable? @Test public void shouldNavigateToPhotosPage() { Navigator nav = new Navigator("http://plus.google.com/"); nav.goToPhotosPage(); assertEquals("http://plus.google.com//u/0/photos", nav.getCurrentUrl()); // Oops! }After eliminating the unnecessary computation from the test, the bug is obviouswhen a test adds more operators or includes loops and conditionals, it becomes increasingly difficult to be confident that it is correct. whereas production code describes a general strategy for computing outputs given inputs, tests are concrete examples of input/output pairsWhen tests do need their own logic, such logic should often be moved out of the test bodies and into utilities and helper functions

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The Deadline to Sign up for GTAC 2014 is Jul 28

Tuesday, July 22, 2014

Posted by Anthony Vallone on behalf of the GTAC Committee complete the formdevelopers.google.com/gtac

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Measuring Coverage at Google

Monday, July 14, 2014

By Marko Ivanković, Google ZürichIntroductionCode coveragelarge body of research How we measured Google build systemGcovEmmaJaCoCoCoverage.pybriefly explained in this article

numbersbefore Results

C++

Java

JavaScript

Python

56.6%

61.2%

63.0%

76.9%

84.2%

Future workjob site

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Testing Blog

Testing on the Toilet: Don't Put Logic in Tests

The Deadline to Sign up for GTAC 2014 is Jul 28

Measuring Coverage at Google

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