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Stephen Ritchie's offerings of ruthlessly helpful .NET practices.
A world-class education continues to become more affordable. The information is disseminating faster and at lower cost. Access to knowledge and new understanding is now mostly limited by your time, attitude and motivation.
MIT OpenCourseWare (MIT OCW) is an initiative of the Massachusetts Institute of Technology (MIT) to put all of the educational materials from its undergraduate- and graduate-level courses online, partly free and openly available to anyone, anywhere.
Source: From Wikipedia, the free encyclopedia (naturally)
This is a great way for people around the world to get a first-class education. Especially in the fields of engineering and science. However, I’m guessing an MIT degree still requires admission, matriculation, tuition, room, board, and other expenses. The learning is mostly free. The biggest investment seems to be your time.
For more information: http://ocw.mit.edu/index.htm
The Machine Learning course, broadcast live from Caltech in April-May 2012.
There is an awesome trend happening. One that I believe will benefit all humankind.
How do you apply this to your software development projects?
The Microsoft ASP.NET site (http://www.asp.net) offers a lot of free educational and training material.
Look around. There are bunches and bunches of educational material offered free-of-change.
- edX is a joint venture involving Harvard and MIT with the goal of improving the quality, effectiveness, and global reach of online university classes.
Build numbering is a topic filled with “political” and “cultural” significance. I mean that within organizations and among developers, we have heated debates over the numbering of software versions. Is this software 2.3 or 3.0? Or should it be 220.127.116.1119, 2.3.5.rc-1, or 2.3.5.beta?
Phil Haack recently offered some important information on Semantic Versioning (SemVer) specification and NuGet build numbering. Since the SemVer convention is a rational and meaningful way to version public APIs, it’s a good one to follow. Here are Phil’s posts:
The basics of SemVer: the version number has three parts, Major.Minor.Patch, which correspond to:
Major: Backwards incompatible changes
Minor: New features that are backwards compatible
Patch: Backwards compatible bug fixes only.
Everything after these three numbers is for a development organization to use, as it sees fit. Personally, I like ever-increasing, always-unique-for-a-major.minor-version integer numbers. Whether these are build numbers or revision numbers they can be managed by the build script or the continuous integration server.
However, build numbering and versioning has political and cultural significance and implications. Sadly, developers cannot always follow rational and meaningful numbering schemes.
The Marketing Department of a commercial software company often wants to control the first two digits of the build number. They love to promote things like the company’s software is no longer version 2.3; now it’s 3.0! This change in major version generates interest and drives upgrade sales. In some cases, the software is a major new release, with significant new features. In other cases, it is just a marketing gimmick; there are only bug fixes and cosmetic changes in the new version.
Internally, developers hate it when Marketing overstates the major and minor version numbers of software. They feel that a minor release does not warrant an increment of the major version number. They want to follow systems like SemVer.
My opinion: As long as the numbers don’t violate the conventions of SemVer, let the major and minor version numbers belong to Marketing.
Marketing controls the product name. I have seen some crazy product name changes come from Sales and Marketing. As long as it isn’t too absurd, I go along with it. Why shouldn’t that be the same way with the major and minor version numbers? If Marketing wants 2.2 to be followed by 3.0, that’s OK with me. Going from 2.2 to 2.5 could represent a more accurate description of the perceived improvement. Either way, I don’t see it as my call. What I don’t like is jumping from 2.2 to 5.0 or regressing from 2.2 to 1.7, that’s absurd. The major version number should never increment by more than one. The combined major and minor number should always represent a decimal number greater than the prior version. Similarly, going from 2.2 to 2.3 must only introduce backwards compatible new features and backwards compatible bug fixes.
Bottom line, let Marketing own the major and minor version numbers. Insist that they follow the basic rules. Give them the guidance that increasing the major version number means “breaking changes are introduced”, “significant new features are added” or “it’s a total rewrite.” Minor version numbers are incremented when minor enhancements are added and bug fixes are made. Marketing must not break the paradigm. They are adults. If they are using sound judgement, let them own the major and minor numbers.
In the .NET world, NuGet is very significant. With version 1.6, NuGet follows the SemVer specification. My current thinking on version numbering is that you ought to follow the version numbering that NuGet follows. The NuGet documentation describes the SemVer spec and what NuGet expects of version numbering.
The CI server is a great way to control and increment the version number.
Incorporate this version numbering into your build script. Chapter 9 of Pro .NET Best Practices covers this topic. The free code samples are available at the bottom of the Apress page for the book, here.
Here is a good way to version assemblies: http://code.google.com/p/svnrevisionlabeller/
Ben Hall describes how to increment the build numbers with MSBuild and TeamCity: http://blog.benhall.me.uk/2008/06/team-city-update-assemblyinfo-with.html
Wikipedia, as usual, has a comprehensive entry on the topic of software versioning: http://en.wikipedia.org/wiki/Software_versioning
Often I am asked variations on this question: Should I unit test private methods?
As a rule of thumb: Do not unit test private methods.
The concept of encapsulation means that a class’s internal state and behavior should remain “unpublished”. Any instance of that class is only manipulated through the exposed properties and methods.
The class “publishes” properties and methods by using the C# keywords: public, protected, and internal.
The one keyword that says “keep out” is private. Only the class itself needs to know about this property or method. Since any unit test ensures that the code works as intended, the idea of some outside code testing a private method is unconventional. A private method is not intended to be externally visible, even to test code.
However, the question goes deeper than unconventional. Is it unwise to unit test private methods?
Yes. It is unwise to unit test private methods.
When you refactor the code-under-test, and the private methods are significantly changed, then the test code testing private methods must be refactored. This inhibits the refactoring of the class-under-test.
It should be straightforward to refactor a class when no public properties or methods are impacted. Private properties and methods, because they are not intended to be directly called, should be allowed to freely and easily change. A lot of test code that directly calls private members causes headaches.
Avoid testing the internal semantics of a class. It is the published semantics that you want to test.
Some dead code is only kept alive by the test methods that call it.
If only the public interface is tested, private methods are only called thorough public-method test coverage. Any private method or branch within the private method that cannot be reached through test coverage is dead code. Private method testing short-circuits this analysis.
Yes, these are my views on what might be a hot topic to some. There are other arguments, pro and con, many of which are covered in this article: http://www.codeproject.com/Articles/9715/How-to-Test-Private-and-Protected-methods-in-NET