The Joel Test Revisited

The ubiquitous Joel Test: 12 Steps to Better Code is almost 20 years old. It was a great foundation, but with the past two decades, is it still relevant? Here’s my review.

1. Do you use source control?

Still valid and vital. But good source control practices are required. Have a master and a staging branch that can’t be pushed to directly. Do pull requests (i.e. peer reviews). Don’t push passwords, put that in a secure vault, scan for personal emails.

2. Can you make a build in one step?

This needs to be broadened to encompass all of CD/CI. Building, testing, and deployment should be one step in a dedicated setup. I’m currently using Codeship for that and loving it!

3. Do you make daily builds?

Again, CD/CI makes this better: build on every change. Less than this is too risky. And days without changes don’t need a build. Come on.

4. Do you have a bug database?

Yes! Essential. But it needs to be curated. If clients can add to it the bug descriptions might be too broad or too vague. Great clients will get that and learn to formulate bug reports correctly.

5. Do you fix bugs before writing new code?

My heart bleeds for this one. Reality will make you classify the bug from trivial to blocking, and bugs that can be worked around will be pushed aside to favour newer features. Fixing bugs first is good advice, but not always workable. But if our aim is the original “better code”, this is a sound practice.

6. Do you have an up-to-date schedule?

Still relevant, knowing that schedules will change on a daily basis. Agile has impacted this greatly. Devs see one sprint ahead, which might be a boon for when it comes to stress management.

7. Do you have a spec?

Specs are so volatile… Needs change fast. Write them down but keep updating them. And how about adding : do you have architectural documentation for when the project is done and slides towards long term maintenance?

8. Do programmers have quiet working conditions?

The first question that’s about the worker building the product. This one could be the toughest in some contexts. And silence isn’t the only factor. We work sitting down. The body takes a toll. Ergonomics are vital. And many programmers don’t like basements, contrarily to some rumours.

9. Do you have the best tools money can buy?

Be smart about this one. So many good tools are free now. And so many essential (and admittedly non-essential) tools are costly. Having to support software using an SDK without access to documentation shouldn’t be an assignment. Machines should be able to be up 100% of the time and perform adequately. Anything too old and slow should be replaced. Fast and stable Internet is vital too. This is what’s running the world now. Everyone should know.

10. Do you have testers?

Yes! Still valid! Programmers 👏 Aren’t 👏 Testers 👏!

11. Do new candidates write code during their interview?

Still valid. Interview questions shouldn’t be gotchas, ever. But problem solving is essential. Just don’t look for syntax errors. That’s not what handwritten coding is for.

12. Do you do hallway usability testing?

If the list was “12 steps to better products”, this would make sense. But this is for better code. A better question would be: Do you have unit tests? Doesn’t have to be TDD. Doesn’t have to be 100% coverage. But more than 0%.

Other questions for better code:

There are other questions that can lead to better code. Here are my additions:

13. Do you use design patterns?

There is such a thing as too much of a good thing though. A metric that could help: Ratio of singletons to other regular classes. Too many singletons means the developers just don’t know when to use them.

14. Do you upkeep the code?

When code is revisited, is it updated to meet new standards? Think ECMAScript 6 and what it brought. Were Promises revised (when appropriate) with the new async/await patterns?

15. Are programmers encouraged to explore new technologies?

This can be facilitated in a few ways. It doesn’t need to be paid time (but it can and boy does this make a company stand out!) If paying for this time as work hours isn’t possible, there are other ways. This is the sort of thing for which you bring out pizza, not at crunch time. Work isn’t a hackathon. If there’s crunch time, meals aren’t an incentive, they’re a facilitator, and extra time means extra pay. No exceptions, unless you want to compromise quality.

16. Is pair programming encouraged?

Some places consider this to be a net loss. Two programmers working on one feature together or two programmers working on one feature each? That’s easy to figure out! Well, no, not so much. If code quality matters, encourage occasional pair programming, and try to mix up the teams.

Fast distance calculation between geo-coordinates

I see this in libraries and it makes my skin crawl: the Great-Circle distance calculation (or GCDC). It is needlessly precise and slow. You will feel the performance hit if you have to do an O(n!) or even O(n log n) operation to sort or cluster points. And its precision is its downfall:

It takes into account the variation of the curvature of the Earth. It’s precise to within less than a meter.

This is too much work for what we need in most cases: a good approximation of distance between two points.

Here is a faster way that’s close enough:

//Supposing:

//lat1 and lon1 as coordinates of position 1;
//lat2 and lon2 as coordinates of position 2;

long meridional_circ = 40007860; // meters
double lat_degree_distance = meridional_circ / 360; // average length of one degree of latitude, or about 111133 meters.
long equatorial_circ = 40075017; // meters
double lon_degree_distance = equatorial_circ / 360; // average length of one degree of longitude AT THE EQUATOR, or about 111319 meters.

//calculate distances separately

double lat_distance = abs(lat1 – lat2) * lat_degree_distance;
double lon_distance = abs(lon1 – lon2) * lon_degree_distance * Math.cos(Math.PI * ((lat1 + lat2)/2) / 180);

//calculate Euclidean distance

double distance = Math.sqrt(lat_distance * lat_distance + lon_distance * lon_distance);

Declare the constants as constants, and you’re good to go. 

Optimization series: steps 0 and 1

I will be doing a series of posts on optimization, namely software optimization for speed, in the coming weeks and months. Optimization is by far my favourite thing in programming. To me, there’s nothing quite like taking code that works and making it code that works faster. I don’t get to do it as often as I’d like, and the same will probably go for you, whether you want to or not, but I will share what knowledge I’ve garnered over the years doing this.

 

Step 0: Pre-preparation

 

(Of course this is 0-indexed…) The very first step, and please pay attention, is that YOU MUST NOT, UNDER ANY CIRCUMSTANCE, BEGIN WITH THE OPTIMIZATION. That is: FIX THE BUGS FIRST. This is critical, optimization is very often a feature, or at the very least a defect correction, but more often than not an improvement. If you speed up code that doesn’t work, it will only crash faster. There is such a thing as preemptive optimization which can lead to more trouble than worth it down the road, and it’s a documented pitfall. Consider yourself warned.

(It goes without saying that standard programming practices must be applied, such as having backups and using a form of version control for your code. You must set that up if it’s not, for your own sanity as well as for the needs of the work ahead.)

 

Step 1: Preparation

 

With a stable codebase and no (known) bugs, we can begin. Optimization (and this is one of the reasons that makes it so attractive to me) is like experimental science. In science experiments, there is a very important notion that applies here. Scientists call it control. For example, for pharmaceuticals, there is usually a “control group” which is given a pill that does nothing, a placebo, along with other groups which will be given the actual drugs being tested. In the end, every subject took “a pill”, and that’s the scientist’s basis for analysis and comparison. This is also taught in high school science: don’t contaminate your samples, which is another way to say “don’t introduce unknowns.” It’s the same thing with software, but we’ll usually talk about benchmarking.

What you need to do is have all the conditions required in order to run your benchmark, in such a way that you can get back to it easily. That could mean working with backup databases, test files, virtual machines with snapshots, etc. If your optimization requires something more “exotic”, say simulating a faint wifi signal, near capacity memory or CPU usage, etc, you need to be able to bring up those same conditions, so that when you test your changes, you’re actually only testing your changes. In all cases, a reference base is needed, an initial state of input. So your first step (well, after fixing the bugs), is to BE ABLE TO EASILY GO BACK TO YOUR BENCHMARK FOR REFERENCE AND COMPARISON. This also implies being able to compare the end result, not just for speed but for accuracy. Because optimization is about finding a quicker route from point A to point B, not ending up at point C.

Got that? Don’t come back until you have that.

Rounding in .NET: A fair warning

Everybody uses the same rounding they learned in school. Only Siths deal in absolutes, as they say, but this is really really basic: .0, .1, .2, .3, .4 round down, and .5, .6, .7, .8, .9 round up. We’ve all learned this in school.

.NET Framework designers have taken it upon themselves to make fools of us all by defaulting the rounding algorithm (used by Math.Round) to something called “Banker’s rounding.” It behaves the same, except for .5, which will round to the nearest even integer. 2.5 rounds down to 2, 3.5 rounds up to 4. This was done so as to distribute .5 evenly up or down. Or a better explanation might be…

Counting objects

This is a variation on the classic C++ approach, adapted to C#. While .NET has its Garbage Collector which takes care of all objects you don’t need, at some point one might need to track how many instances of an object were created, or are active.

public class SomeClass
{
    public static int ObjectsCreatedCount = 0;
    public static int ObjectsActiveCount = 0;
    public SomeClass()
    {
        ObjectsCreatedCount++;
        ObjectsActiveCount++;
    }
    ~SomeClass()
    {
        ObjectsActiveCount--;
    }
}

That way, you can use SomeClass.ObjectsCreatedCount to know how many objects were created, and SomeClass.ObjectsActiveCount to know how many objects are still around at any point.

Another thing of note: C# classes do have destructors, contrary to popular belief. It has no delete keyword because of the Garbage Collector, and there’s little management to do for memory, but there’s still a possibility of using a destructor.

Worst way to do a sum

I’m dealing with some seriously bad code. It’s sort of like this.

Suppose you need to add two integers in C:

    int sum(int x, int y)
    {
        return x+y;
    }

Let’s not even consider nastiness like int limits, just a plain sum that works. That above is the sane way. That’s how you work. You do a single, tiny function that does a single job well.

This is the legacy I’m dealing with:

    //Declared globally
    int sum1 = /* a value */;
    int sum2 = /* another value */;
    int sum; /* the result */
    sumx(); /* execution */
    //...
    void sumx()
    {
        sum = sum1+sum2;
    }

Technically, it works. Same result. What’s the difference? Maintainability.

The one rule for software maintenance

Code which cannot be maintained might as well just not work or even exist.

– Thierry Eude, Ph. D., Ing. jr., Université Laval

Cast away

My C++ class is done, and I feel like I learned some tiny things here and there, mostly refresher stuff, but not a lot of meat to sink my teeth into.

So, to learn more, I turned to Stack Overflow, and while wanting to be helpful, got served. It’s alright, it’s cool, I learned I had still lots to learn. And that’s why I will talk about casting.

Usually, in a function, you should get your types right, and avoid wasteful casting. That’s true. Compilers throw warnings at you if you don’t respect types, and that’s usually where you need to be explicit about what you mean. C has the classic cast, what most call the C-style cast:

    int i = 35;
    float f = (float)i;

C++ offers a lot more tools. Most of the time, we’re casting to another type to adapt to a situation, a function, etc. C++ allows us to be more explicit, which is good, because you’re making your meaning clear to future maintainers of your code (and that can be yourself). Never neglect the power of explicit code. Don’t just cast to make it work (or not send a warning), cast and be clear about your intentions.

These are called casting operators, and they go as follows.

First, const_cast.

const_cast exists to deal with whether a variable or parameter is constant or not. Sometimes, you need to get rid of “const” for just a bit. Casting it C-style works, but the C++ way is crystal:

void nonconstfunc(int *i);

void constfunc(const int *i)
{
    nonconstfunc(i); //error, this will not compile
    int* i2 = const_cast<int*>(i); // but convert it to a non-const int pointer
    nonconstfunc(i2); //and use the non-const copy instead!
}

Next is reinterpret_cast.

reinterpret_cast does a very specific job: it can cast a pointer to an integral type and back. So if you have a pointer and you want to print its address, say, you can use this:

int main(int argc, char *argv[])
{
	long adr = reinterpret_cast<long>(argv);
	cout << adr;
	return 0;
}

It’s a very specific use. Changing the value and casting it back to pointer is definitely not recommended. You can see this being used to hash an address and put it in a hash table, for example.

The next two are opposite sides of the same coin: dynamic_cast and static_cast. I don’t fully grok them yet, so I will not elaborate on them in this post. Suffice it to say that they complement each other. dynamic_cast runs real-time checks, while static_cast does not, which makes it faster. Both can cast up or down a chain of inheritance. So I will grok and get back to this.

Simple C# Serialization

(Kudos if you noticed the alliterated title)
(Edit: this is an old article I never published. Until now! I hope it serves as a nice introduction to beginners).

Serialization is a thing I had (until recently) left untouched. For too long. Well, no more. Here are the basics.

What is serialization?
Simply put, it’s taking an object’s value(s) and writing them to a file (or a buffer, but I’m not covering that here) for transmission or storage.

What is deserialization?
It’s the reverse, building an object from a file (or buffer).

Why serialize?
Serialization can be used for various reasons, such as transmitting data to another computer or storing it. Storage could potentially be done with a database, but even something portable like SQLite is another thing to maintain, whereas for minimal needs, serialization offers quick and dirty clean storage for later use. For example, I’m using it for storing a few sets of parameters for batch processing.

Here’s how. I will be using the simplest form of XML serialization (that is, writing to, and naturally reading from XML), not Soap, but with the very vanilla System.Xml.Serialization namespace.

First, add System.Xml to your project’s references.

Now, we’ll design the basic class we want to serialize. First, the class without the serialization attributes:

public class ClientInfo
{
    public string ClientName { get; set; }
    public int ClientId { get; set; }
    public DateTime ProcessTime { get; set; }

    public ClientInfo (string clientName, int clientId)
    {
        ClientName = clientName;
        ClientId = clientId;
    }
}

To serialize, we’ll need the proper namespace, so add:

using System.Xml.Serialization;

in your using block at the top.

Next, we’ll decide what we want to serialize. Let’s say ClientName and ClientId, but ProcessTime shouldn’t be serialized at all (for some reason. Hey, I just needed the example).

So, we’ll need to tell the compiler that the class is serializable, simply by adding the attribute above the class declaration:

[Serializable]
public class ClientInfo
{/...

By default, all fields become serializable. Let’s specify the field to ignore appropriately:

    public string ClientName { get; set; }
    public int ClientId { get; set; }
    [XmlIgnore] //Tells C# to forget about that value for serialization
    public DateTime ProcessTime { get; set; }

Serialization also requires a default constructor. And the nice thing is that it does not have to be public, so your class logic can remain the same from outside (i.e. no default instantiation if you don’t want it):

    private ClientInfo()
    { }

The final result:

using System.Xml.Serialization;

[Serializable]
public class ClientInfo
{
    public string ClientName { get; set; }
    public int ClientId { get; set; }
    [XmlIgnore]
    public DateTime ProcessTime { get; set; }

    public ClientInfo (string clientName, int clientId)
    {
        ClientName = clientName;
        ClientId = clientId;
    }

    private ClientInfo()
    { }
}

And we’re done for that part! Now, suppose you want to serialize that into an Xml file. Use a function like so:

public static bool SaveConfig(ClientInfo clientInfo, string filePath)
{
    bool success = false;
    using (FileStream flStream = new FileStream(filePath, FileMode.Create, FileAccess.Write))
    {
        try
        {
            XmlSerializer xmlSerializer = new XmlSerializer(typeof(List));
            xmlSerializer.Serialize(flStream, clientInfo);
            success = true;
        }
        //do add proper handling of possible stream exceptions here
        finally
        {
            flStream.Close();
        }
    }
    return success;
}

And reading, essentially taking the XML class and making it into an object is just as easy, it’s called deserialization:

public ClientInfo LoadConfig(string filePath)
{
    if (!File.Exists(filePath))
        return null; //Or ClientInfo.Default if you made one

    ClientInfo clientInfo = null;
    using (FileStream flStream = new FileStream(destFileName, FileMode.Open, FileAccess.Read))
    {
        try
        {
            XmlSerializer xmlSerializer = new XmlSerializer(typeof(ClientInfo));
            clientInfo = xmlSerializer.Deserialize(flStream) as ClientInfo;
        }
        //do add proper handling of possible stream exceptions here
        finally
        {
            flStream.Close();
        }
    }
    return clientInfo;
}

This is just the tip of the iceberg. You can serialize/deserialize sub-objects, collections, etc. This is very useful for reading and writing back. And of course if you need to serialize/deserialize something large, there are better ways, like binary serialization!

La promesse Agile

(yup, this one’s in French!)

Agile, ou l’Agilité, est une méthodologie de gestion à la mode en informatique. On se veut Agile, on se dit Agile, mais l’est-on vraiment? Ou est-on réellement prêt à le devenir?

Cette méthodologie est basée sur des valeurs qui tendent vers une meilleure organisation du travail de développement logiciel. Dans ce but, elle accorde beaucoup d’importance à l’équipe de développement. Elle vise à valoriser

• les individus et leurs interactions plutôt que les processus et les outils
• des logiciels opérationnels plutôt qu’une documentation exhaustive
• la collaboration avec les clients plutôt que la négociation contractuelle
• l’adaptation au changement plutôt que le suivi d’un plan

Elle prévoit divers mécanismes pour concentrer les efforts, le plus connu étant le Scrum.

Le Scrum est une brève rencontre quotidienne qui permet de s’assurer de la progression d’un projet. Cinq minutes, et debout! On est loin du traditionnel meeting de la haute direction. Il est dirigé par un ScrumMaster, qui se fait le protecteur de l’équipe en éloignant les interruptions et en maintenant le contact avec le client.

Le but avoué d’Agile est de concentrer le talent et le travail pour satisfaire les demandes du client. Mais son but ultime est de favoriser le développement humain. La nature même du travail dans le domaine du logiciel demande un apprentissage perpétuel. Le développement n’est pas un ouvrage de production constante. En effet, ce n’est pas une chaîne de montage : c’est un processus on ne peut plus humain, centré sur ce qui qualifie l’homo sapiens, la pensée. Mais c’est justement dans l’obligation de livrer un produit qu’on peut perdre l’aspect humain. Alors intervient Agile!

Présentée dans le manifeste Agile, le manifeste tient compte des réalités du monde des affaires : les besoins changent et grandissent rapidement. Il y a une foule de détails et d’étapes à produire dans une solution logicielle. L’élément central de tout cela n’est pas la productivité, ou même l’ordinateur, c’est le facteur humain. En laissant les développeurs s’autogérer (dans le cadre du projet), on ne tombe pas dans les pièges du micro-management. Les développeurs prennent conscience de leur capacité, de leur utilité et deviennent (ou demeurent) proactifs par rapport au développement, plutôt que réactifs. Le stress diminue, les dossiers se règlent, le produit se développe. Mais surtout, les développeurs sont heureux, ils s’épanouissent dans leur travail.

Et tout cela se fait sans lunettes roses, parce que le client est en contact constant! Ce que plusieurs gens retiennent de l’Agilité, ce sont les cycles courts. Petit ajout au logiciel, mise à jour, informer le client. Le rythme n’est pas une fin en soi, c’est la réalisation en continu de ce que le client a besoin.

Bien entendu, on ne devient pas Agile pour simplement le devenir. Ce n’est pas une finalité, c’est un changement constant. C’est une adaptation des êtres humains dans l’organisation à une méthodologie. Devenir Agile est un processus… Agile!