Wednesday, July 22, 2009

Thinking that you can learn it all

[This was originally posted at]

I think .Net is too huge for one person to learn it all, and it's just getting bigger - like a galaxy. However, sometimes an optimistic developer may get the temporary delusion that they can learn it all, or at least the parts that matter. How could someone become so optimistic?
  • Unexpected free time.
  • Something came easier than expected.
  • You're on a prestigious fast track project.
  • A real good teacher explained something very well (and quickly).
  • You're kidding yourself - you're just skimming, or only looking at buzzwords, not really digging into the tech.

Basically, if things are temporarily going well (i.e. you're absorbing new concepts really fast), it may be tempting to think that "ah ha, this learning thing has finally clicked, and it will always go fast from now on!" Oh, how I wish...

Sunday, July 19, 2009

Would you still write unit tests even if you couldn?t automatically re-run them tomorrow?

[This was originally posted at]

I am constantly amazed at how difficult it is to encourage software engineering teams to adopt unit testing. Everyone knows (wink wink) that you should test your own code, and we all love automation, and all the experts are pushing for it, and we all know how expensive bug fixes are, etc... Yet, there are still many experienced and good-hearted developers who simply don't write unit tests.

I think a critical question may be "Would you still write unit tests even if you couldn’t automatically re-run them tomorrow?"

Here's why - most managers who push unit tests do so saying something like "Yeah, it's a lot of extra work to write all that testing code right now, but you'll sure be glad in a month when you can automatically re-run them. Oh, and by the way, you can't go home today until you fix these three production issues."

The problem is this demotes unit testing to yet another "invest now; reward later" methodology. This is a crowded field, so it's easy to ignore a new-comer like "unit testing". Obviously, most devs live in the here and now, and they'll just trying to survive today, so they care much more about "invest now, reward now".

The "trick" with unit testing - at least with basic unit testing to at least get your foot in the door - is that it adds immediate value today. Even if you can't automate those tests tomorrow, it can often still help get the current code done faster and better. How is this possible?

  • Faster to develop - Unit testing is faster to developer because it stubs out the context. Say you have some static method buried deep within your web application. If it takes you 5 minutes to set up the data, recompile the host app, navigate to the page, and do whatever action triggers your method being called - that's a huge lag time. If you could write a unit test that directly calls that method, such that you can bypass all that rigmarole and run the static method in 5 seconds - and now you need to test 10 different boundary cases - you've just saved yourself a good chunk of time.
  • Think through your own code - Unit testing forces you to dog food your own code (especially for class-library APIs). It also force you to think out boundary conditions - per the previous question, if it takes several minutes to test one usage of a function, and that function has many different boundary cases, a time-pressed developer simply won't test all the cases.
  • Better design - Testable code encourages a more modular design that is more flexible to change, and easier to debug. Think of it like this: in order to write the unit test, you've got to be able to call the code from a context-free, class library; i.e. if a unit test can call it, then so could a windows service, web service, console app, windows app, or anything else. Every external dependency (i.e. the things that usually break in production due to bad configuration) has been accounted for.

Even if you could never re-run those unit tests after the code was written, they are still a good ROI. The fact that you can automatically re-run them, and get all the additional benefits, is what makes unit testing such a winner for most application development.

RELATED: Is unit testing a second class citizen?, How many unit tests are sufficient?, Backwards: "I wanted to do Unit Tests, but my manager wouldn't let me"


Sunday, July 12, 2009

The address's State field may contain more than just the 50 states

[This was originally posted at]

Most business applications eventually ask the user to enter an address. There's the user's address, shipping address, their company's address, maybe an emergency contact's address, address history, travel-related addresses, financial addresses, etc... Most addresses have a city, state, and zip. While city and zip seem simple (more on that later), many devs initially expect the "State" field to be simple - perhaps a two-character column that can store the 50 US states. However, it can quickly balloon to something much more complicated (especially if you're troubleshooting some legacy app). Besides the standard states, it could contain:

Military codes (reference)

Armed Forces AfricaAE
Armed Forces Americas (except Canada)AA
Armed Forces CanadaAE
Armed Forces EuropeAE
Armed Forces Middle EastAE
Armed Forces PacificAP

US Possessions (reference)


Perhaps Canadian provinces? (reference)

British ColumbiaBC 
New BrunswickNB 
Newfoundland and LabradorNL 
Northwest TerritoriesNT 
Nova Scotia NS
Prince Edward IslandPE 
Yukon YT

Generic codes to indicate international use?

Foreign CountryFC
Out of CountryOC
Not ApplicableNA

Or, specific applications may try their own proprietary international mapping, like "RS" = Russia. This might work if you're only doing business with a handful of countries, but it doesn't scale well to the 200+ (?) existing other countries (i.e. I would not recommend this. Use a "Country" field instead is feasible).

Special codes to indicate an unknown, or empty state?


Perhaps, for some reason, the application developer isn't storing just 2-char codes, but rather integer ids that map to another "States" table, so you see numbers like "32" instead of "NY" ("New York")?

Or, even worse, they're shoving non-state related information into the state column as a hack that "made something else easier".

How many distinct entries could you have?

  • With 26 letters, you've only got 26 ^ 2 = 676 options.
  • If you use numbers too, you've got (26 + 10) ^ 2 = 1296 options.
  • If you start using lower case letters (SQL is case-insensitive, but maybe this impacts managed code), then you've got (2 * 26 + 10) ^ 2 = 3844 options.
  • Add in some special characters (such as spaces, periods, asterisks, hyphen, underscores, etc...), maybe 10 of then (if the column isn't validated on strictly alpha-numeric), and you've got (2 * 26 + 10 + 10) ^2 = 5184 options.

That's potentially 100 time more than just the 50 US states. Of course, for new development, we'd all prefer some clearly-defined schema with referential integrity and a business-sensible range of values. However the real world of enterprise applications is messy, and you have to be prepared to see messy things.

It sounds simple, but that innocent "state" field can quickly get very complex.

Thursday, July 2, 2009

Why a manager may not want you to learn

[This was originally posted at]

I'm a huge advocate of learning. And it's natural for devs to want to pick up new stuff. However, many devs don't realize that they may report to a manager that actually wants to prevent them from learning new things - even on their own personal time. I think this type of manager is rare. However, it's good to be aware in case a manager is (perhaps unintentionally) "sabotaging" your learning.

I hesitated about writing this post lest it seem to cynical or jaded, but it's worth discussing as developers should be aware of such things. Note that there is not one specific person/event/incident that I have in mind, but rather glimpses of things over the last 10 years.

  • Their control - They may want to be in control, and you learning new things that they don't know takes away from their control.
    • They may want to understand the entire architecture themselves. It's sort of a "not built here" applied to a personal level - "If I don't already know it, it must not be necessary."
    • They may not want to learn the new stuff themselves. If you're a tech manager, and all your devs learn the next wave of technologies, it pressures you to learn the new wave as well, else you look obsolete.
    • They don't want you exposing their mistakes. Say a senior developer wrote a bad messaging framework. As long as no other employee has a clue about messaging, no one knows that they made a bad mistake.
    • They want you to "suffer" just like they did. Often new techs make it easier to do something, and rather than have the easy way out, you should do it the original way so you "understand what's really going on". Think using assembly language or C++ instead of a higher-level language like C#.
  • It doesn't support the immediate work
    • They may think it's a waste of time - "We've already invested in this architecture, we don't need anything else." Even though it's your own time, they'd rather you spend overtime on "useful features", like copying and pasting tedious code.
    • It competes with your day job - If you're researching some cool XNA technology, which is a lot more fun than the drudgery of some bad architecture, it may compete. Suppose you work at home, it might "distract" you.
    • It may be misapplied. New stuff is risky, and could be buggy or applied incorrectly - which would hurt the project.
    • Their afraid that "smart" developers are hard to manage. Smart developers can sometimes be total egomaniacs to work with (because they think they're so smart), and management may not want to even think about dealing with that.
  • You may leave
    • You may outgrow your company and leave-  If your company is stuck in the dark ages, they may want to keep everyone's technical skills "in the dark" as well, lest an employee "see the light" and leave.
    • It makes your more marketable, and you may leave. If you're stuck with some niche technology on an obsolete framework, you aren't very marketable and hence can't get another job, and hence your boss has tremendous control over you.

Examples of how a manager might unintentionally discourage a developer from learning:

  • Financially reject anything (like buying new books or tools or paying for a class)
  • Undermine your confidence ("Why would you need that") or question your motives.
  • Deny you resources, such as preventing you from installing anything on your machine (open source code, tools, etc...)
  • Never affirm new learning or innovation. They tell you "good job" for getting that feature done, but won't affirm picking up new technologies.
  • Never provide their software engineers with a continuing-education plan. Ask yourself, how do developers go "to the next level" in your team? Does management help them?

It's sad, but some companies are structured where it's not in the manager's best interests for the employees to "wise up". The managers want hard-working, honest people who are easy to manage, but they don't want to deal with innovation or smart developers.

LINK: Does your Project encourage learning