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.

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.

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!

Simple trick to optimize SQL joins

This comes up very often on StackOverflow: Make my query faster!

My first trick is always the same:

SmallTable INNER JOIN BigTable

And not the other way around. Your mileage may vary.

The banker’s database

This is not from me, it’s from a teacher of mine. I thank him to this day for this wonderful image.

Most database classes will teach you how to store data for a few simple models (a store with an inventory, sales, and customers, for example) and through that many will believe in a purely relational model. 100% theoretical. Even when doing actual database work, first database designs will be very much purely relational. And changing database engines is only the best occasion to re-achieve that perfect model!

Let us consider the database for a bank.