Quote

Readable Code: Name Everything

Consider the following code samples.

// Specimen A 

if ($forceClose !== ' ' && $forceClose !== NULL && $issues['forcedClose'] && $forceClose > 0) 
     { 
     //ONLY SAVE IF 1, NEVER TOGGLE BACK
     $this->saveAttrForUser($user, 'forced_close', $forceClose);
     if ($forceClose == '1') 
         {
         Log::saveWrite("App killed");
         }
    }
// Specimen B
// note the prefix 'b' indicates type Boolean, the prefix 's' indicates type String
$bGotValidMessageFromClient = !($sForceClose !== ' ' && $sForceClose !== NULL);
$bAppPassedExitMessage = $aIssues['forcedClose']; 
$bExitWasForceful = ( (int)$sForceClose > 0);
$bAppWasForceClosed = $bExitWasForceful && $bGotValidMessageFromClient && $bAppPassedExistMessage;

if ($bAppWasForceClosed) 
     { 
     // A comment here that would mean something...
     $this->saveAttrForUser($sUserId, 'forced_close', $sForceClose);
     $bForceCloseWasAKill = ($sForceClose == '1');
     if ($bForceCloseWasAKill) 
         {
         Log::saveWrite("App killed");
         }
    }
These two samples contain the exact same logic. The former is more direct, essentially it inlines all of the variables in the latter. And that is why it is worse. A variable serves as a unit of abstraction, and a well-named variable is a comment; thus having more variables is better. In fact, all if conditions should the form if ($bSomeVariable) {, that is, never put a complex expression within the parentheses of the if. If the logic is particularly complex then use multiple variables, as seen in the sample above.

All if conditions should the form if ($bSomeVariable) {

At first glance, the bottom example is longer and may look intimidating. But it is superior because it exposes its internal logic. Try deciding what the top code does, and what ‘1’ indicates in that code. Then consider the bottom code. The top is an actual code sample.

And while we’re adding in these extra variables, let’s name our variables clearly. Programmers seem to have some unspoken assumption that variable names need to be less than 10 characters and not have prepositions… Maybe this made sense when you had an 80 character wide monochromatic screen with no form of autocomplete, but technology has made that trend obsolete.  I suspect most people would try to turn the variable name $sLinkToUniversalDownloadPage into something like $sUniversalDownloadLink which is inferior because it is ambiguous (is the link universal or the download universal?).

Or, for example, what would a function named “OpenFileLock” do? Is it opening a lock on a file? Is it filing a lock (in some kind of lock registry)? Is it locking an open file? Each of the three words in the title can be read as a multiple parts of speech (i.e. verb, noun, adjective, etc). Or perhaps FileLock is an existing class in this codebase. Prepositions here would make all of the difference.

Name everything; name it well.

Death By Metrics

‘A little knowledge is a dangerous thing’ – Alexander Pope

 

TL;DR – Graphs, dashboards, and metrics give a psychological illusion of control and understanding which is usually false and can be worse than no information at all.

Why is it so easy to fall subject to crappy metrics? Let’s consider a story. You’re a project manager and you just got yelled at because the engineering project you manage is already 2 sprints behind. You feel helpless. You asks the engineers why everything is taking longer and they give technical explanations about unknowns that you can’t see at all. You really don’t know anything.

Then something magical happens: you discover you can look at the engineers’ pull requests, and see how many PRs they make each day and how many diffs are in them. You start to look at these and start to notice patterns. Maybe less PRs get done on work from home Mondays… are they slacking off? When all you have is a nail, everything looks like a hammer.

And you just ruined the company. Suddenly you’re wondering why Bob has the fewest commits, why there are fewer PRs on work-from-home Mondays, why there has been a decrease in number of PRs last month. The answers respectively are: Bob is the only one to comment  his code so everybody except him is sped up because of it, sprints start on Mondays and fewer PRs have 1 day turn-around so this biases your results. Everything your one tool might lead you to assume has been entirely incorrect.

Or worse, you decide to evaluate engineers based on their Jira tickets. You have engineers estimate their tickets and then see if they can meet their goals on time. Suddenly you have incentivized your engineers to overestimate tickets, play “hot potato” with responsibilities (“Not really a bug! Ticket Closed!”), not help each other (teaching time just makes you look slower), and not invest in long-term architectural improvements that won’t show immediate benefits.

Or you judge the success of a UI change based on a funnel. In an attempt to get the best open-rate for your marketing email you have somebody come up with various subject lines and pick whichever has the highest open-rate. This is an A/B test. Suddenly you’re sending out emails with link-bait titles like “See what your friend posted about you,” that get a high open-rate but immediately get deleted for being deceitful once opened. Or your new button placement gets tons of clicks because it’s too close to the scrollbar.


Or worse yet, you decide to judge the success of your company based on Monthly Active Users. 
You have your awesome facebook game and have 30 million MAUs. You force all of your users to send out invites to all of their friends and Viola 31 million MAUs! You change your code so that every one of your users must send invites to friends every week. Now you have 32 MAUs. The graphs look pretty convincing, you get promoted. And you wrecked the company. A year later facebook changes the rights to your app so that you can’t spam its users, your users have been pressured by their friends to stop spamming invites, your entire company has become a laughing stock in the gaming industry and is now lampooned everywhere for the rest of its existence.

The common pattern here is  individuals trying to substitute a simplistic chart in place of deep industry experience. It is people with finance degrees changing videogame experiences, MBAs insisting on multiple A/B tests to change an icon, or a non-technical hiring manager not calling a Bill Gates for an interview because he doesn’t have a CS degree.

SEO is critical to running a business well, and should be accounted for in a business plan in order to help grow a successful, sustainable business (check the Victorious website to get all the details). I know I said I’d be getting back to this in a future article, but now it’s high time to bring the technical portions to a close. What I want to look at now is the business side of SEO. How do you find traffic, how do you get traffic, how do you build your site? How do you use Google and your website to attract visitors? I’m going to take a look at the last two points first.

What Are The SEO Benefits of Social Media?

What Makes a Good Landing Page?

The first thing you need to be able to do when writing your website’s home page is figure out what page your visitors are on. What type of site do you want your visitors to come to? There are a few things to think about here. You need to have a decent to excellent navigation bar, and all the pages of your site should lead people through it. This, of course, goes hand-in-hand with having a clear purpose and some kind of headline. The purpose of your site needs to serve as your focus, and the headline should keep the readers distracted from any details the page doesn’t tell them immediately. This goes for every page on your site, so I won’t give any examples, but the key is that you want it to be a compelling call to action in the eyes of your readers, with a clear goal in mind. And once they’ve got a clear goal, your page will have to get them to accomplish it, and that’s what makes your visitors stick around longer.

Creating a great landing page is so important because it communicates to the reader what they need to do, and what benefits they’ll receive from doing so. A visitor to your site will likely need to perform a few tasks in order to reach their goal. Perhaps they want to buy a book or an e-book, perhaps they want to read a book, perhaps they want to research and decide which books to buy.

“Distinguish Navigation From Content”

In my UI manifesto I mentioned a rule of good design: “distinguish navigation from content.” That means that for all information your application gives, it should be immediately and unmistakably apparent whether the information is situational data (i.e. content such as a particular webpage) or a application functionality (i.e. navigation, like the address bar). This should be apparent from the very first use without having to try it out.

Metaphorically speaking, if you run Safeway, don’t make an employee uniform that is simply a red shirt; if you do that then anybody who walks in with a red shirt could be mistaken as an employee. Make the distinguishing feature something that cannot be mimicked.

Screenshot from youtube, yellow circle added obviously.
Screenshot from youtube, yellow circle added obviously.

Screenshot from youtube
Notice how there is no visual change whatsoever as the mouse covers the x button.

 

 

A real life example from just this week. Youtube failed to do this. Notice this particular ad shows as “x” button in the uppper-right that indicates the ad can be closed. How do I, as a user, know that this is a real X button made by youtube, and not a drawn x in the ad image itself that will trick me into clicking the ad? I don’t, because the the X acts identical to the rest of the ad, the hover icon is the same, no css changes, the two possibilities are indistinguishable until I actually try it out.

How could you fix this? Make the X button partially leave the ad box in the upper right (an area that I can infer the ad doesn’t have permission to draw to) and have it highlight its border yellow when it is hovered (this assumes that the youtube ads are not mouse-responsive, which is true at the time of writing).

How I propose youtube mid-reel ads should behave
How I propose youtube mid-reel ads should behave

What’s the big deal?

So, what is the big deal? Afterall, clicking the X in the youtube ad does end up closing it, seems pretty minor.

It’s a big deal because it’s a systemic problem following a very basic formula that is easy to fix. The general principle behind “distinguish navigation from content” is that the user always needs to be aware of who they are communicating with. 

An old virus trick, back when viruses spread across file-sharing networks, was the someMusic.exe trick, where a trojan would be crafted that would have the default icon of windows media player. Hence, if a user had file-extensions turned off on a PC computer (the default), the file would appear exactly like a music file and would be double-clicked readily. This is again an example of a blurring between communication; the operating system isn’t communicating unambiguously if the icon you are seeing is a certification of file type or is content picked by the application’s creator.

Can you figure out what's going on here? It's all about distinguishing the source of the content.
Can you figure out what’s going on here? It’s all about distinguishing the source of the content.

Refactoring with Functional Programming Like a Boss in Javascript

An example case for refactoring with javascript with functional programming.

Let’s consider an issue that recently came up for a game I was working on. I wanted to effectively create a gradient across the time dimension (i.e. that is a smooth color transition over time). This can create a flashing effect or be used for a number of other cases. In order to make this versatile I decided I wanted a function that would take two colors, and a float (0 to 1) that would represent how much of color2 should be used in the mixture (the rest would be color 1). Thus at partial_mix(c1, c2, 0) we should get just c1, and at partial_mix(c1, c2, 1) we should get just c2.

A sample solution ***BAD CODE***:


/**
* A bad solution to this problem
*/
partial_mix: function(c1, c2, pct_b) {
var red1, blue1, green1, red2, blue2, green2; 
red1 = parseInt(c1.substr(0,2));
green1 = parseInt(c1.substr(2,2));
blue1 = parseInt(c1.substr(4,2));

red2 = parseInt(c2.substr(0,2));
green2 = parseInt(c2.substr(2,2));
blue2 = parseInt(c2.substr(4,2));

var mixture = mix(red1, red2, pct_b) + mix(green1, green2, pct_b) + mix(blue1, blue2, pct_b);
}

function mix(n1, n2, pct_b){
return (n1 + (n2 - n1) * pct_b).to2dhex();
}

Problem 1: Not dry across Red, Green, and Blue. We did the exact same thing to red, green, and blue, yet we copy pasted to handle the redundancy. Not good. Better to use arrays (with the added benefit of easing the process of adding an alpha color later):


var x, color1 = [], color2 = [], result=[];
for (x=0; x < 3; x++) {
color1[x] = parseInt(c1.substr(2*x, 2*(x+1)), 16 );
color2[x] = parseInt(c2.substr(2*x, 2*(x+1)), 16) ;
result[x] = mix(color1[x], color2[x], pct_b);
}
return result.join("");

Problem 2: Code assumes 6 digit format. What if we want to be able to pass 3 character formats too (for either, neither, or both parameters)?

It should be apparent pretty quickly that it’s not pretty to make the code we have versatile in this respect. Instead let’s regularize our input so that it always is 6 digit then leave our code intact:


var doubleString = function(str) { return "" + str + str;}; 
var toSixDigitColor = function(color) { 
    if (color.length < 6) {
      return color.split("").map(doubleString).join("");
    }
   return color;
}

c1 = toSixDigitColor(c1);
c2 = toSixDigitColor(c2);
.
.
.
}

Problem 3: Still duplicates the code performed on color1 and color2:

mix_colors: function(c1, c2, pct_b) {
var mix = function (c1, c2) { ... };
var doubleString = function (str) {...}; 
var toSixDigitColor = function (color) {...};

var shades = [c1,c2].map(function(color) {
color = toSixDigitColor(color);
return color.split("").chunk(2).map(function(a) { return parseInt(a.join(""),16); }); /* convert to an array of 3 values */
});

return _.zip(shades[0],shades[1]).map2red(mix).join("");
}

And that’s what I call leveraging functional programming in javascript. We know it’s well-written code because when we ask what we have to do to add an alpha color, we realize the answer is nothing, it’s versatile enough to do it automatically (even when we combine the requirements of allowing single-digit colors). Notice I pull in underscore for zip, and write two custom functions: map2red and chunk.


Number.prototype.to2dhex = function() { return ("0" + parseInt(this).toString(16)).substr(-2); };

// More on a more general solution to this later
Array.prototype.map2red = function(func) { return this.map(function(v) { return v.reduce(func); }) };

// Breaks an array into sub arrays of length = size
//this is begging to be rewritten as a right apply on divide composed with parseInt passed to _.groupBy
Array.prototype.chunk = function(size) { 
var tmp = [], x; 
for (x=0; x < this.length; x++) {
  tmp[parseInt(x/size)] = tmp[parseInt(x/size)] || []; 
  tmp[parseInt(x/size)].push(this[x]);
} 
return tmp; 
};

Thoughts on the equation of automated testing

Like any other principle, types of testing justify their existence in the time they save you. That is, presuming that software quality is ensured by manual testing in the absence of automated testing, the criteria for telling if adding a test is appropriate is whether the time taken to write the test is less than the expected time saved by the test.

I want to touch on the notion of testing everything. Aside from being inefficient, I’m confident it’s not realistically possible. That is: I’d wager that for any real, used codebase with a set of tests one can write an alteration that will break the codebase while keeping all the tests passing.

If you accept the conclusion that testing everything isn’t plausible (and no, 100% code coverage certainly isn’t testing everything), then the question becomes when/where do we test? Well, obviously in cases when the time saved exceeds the time spent implementing the tests. But let’s break this formula down a little. What factors influence the time saved and inform the decision of which things to test?

  1. The probability that code will break (and the number of times)
  2. The difficulty of manual testing
  3. The probability that the test will catch the code breaking

This is a start, let’s break it down further:

  1. The probability that code will break (and the number of times)
    • Amount of change to be made to code
    • Difficulty of code
    • Team Size (i.e. people working on code who don’t understand it)
    • Intensity of external factors/dependencies (environments)
  2. The difficulty of manual testing
    • The variety of different cases in the piece of code (“branchiness”)
    • The visibility of a problem when present
  3. The probability that the test will catch the code breaking

Based on this list, a hypothetical case where implementing a unit test might be the most valuable:  You have a complicated algorithm that uses advanced mathematics you don’t entirely understand which you will need to optimize several times for speed. Moreover, other team members will be working on it too. It relies on special GPU processing which has varying logic for different hardware. It also has branching logic that requires at least 8 test cases to ensure accuracy. Because the math is so complex, determining if the function has answered correctly requires looking at every digit of a 15 digit number.

A hypothetical case where implementing a unit test might be the least valuable:  You are putting one line of code into your app’s startup to set the background color to steel-grey. It’s a basic 1-liner. Nobody else will touch your code, and you know for a fact from your waterfall documentation that this requirement will never be altered. Your app only runs on a very specific device on one OS. There is no special logic involved. Every time you startup your app (which takes .01 seconds) you’ll immediately notice whether or not the background color is right. 

I believe an expert engineer will always be doing this math with all code he writes, while keeping in mind a margin of error in his estimations. And I think any engineer who opts for a simpler equation is being simplistic and in that respect, the less advanced engineer.

The [limited] Role of Principles

A programming principle should only be followed when it provides more long-term benefit than any alternative. This may seem self-evident; it should be apparent from the fact that a principle that doesn’t provide long-term benefit obviously isn’t a good principle.

This is something that mediocre problem-solvers don’t always understand: deviation from generally accepted principle can be a sign of weakness or, contrarily, a sign of strength.

To take an analogy, in chess it is said that a rook is worth five, a bishop three, and a pawn one and so on. These facts aren’t anywhere in the rules of chess, they are just very good approximations, overall, that emerge from the game. About 90% of the time, you can use math based on these numbers to make good decisions.

However, 10% of the time other situation factors supersede this principle. Though there is an appeal to such simplicity, as one becomes closer to a master of chess he must let go of these numbers and move to a more advanced situation calculus. The same applies to coding.

Even the purest of coding principles have exceptions: though you’ve probably never considered it, every time you copy-paste you participate in a violation of DRY.

I’d like to reiterate, every single (non-trivial) coding principle necessarily has an exception. Why? Because every principle incurs a cost of a situation benefit. And for any such principle we can imagine a scenario, however unlikely, where the situationality of that benefit is totally avoided.

There is only one universal principle of problem-solving: the cost-benefit analysis. Every other principles only offer value as heuristic approximations. This is the calculus by which an expert must weigh the relevance and generality of any other principle.

A UI Case study: Chrome Developer Tools

(All pictures taken at the time of writing, no doubt features and interface will change with time)

For this case study I’ll pick on chrome because it’s hands-down my favorite browser, and because I want to elaborate on the criticism I made in my UI manifesto. It’s excellent in many ways, particularly the developer tools. However, I periodically still learn about cool hidden features it has.

Case in point: http://www.igvita.com/slides/2012/devtools-tips-and-tricks/ . It’s a mixed compliment to have an article written about your software that entitled, “Wait, [your software] can do that?” It’s great to impress with your feature set, but the fact that such an article needs to be written to unearth these capabilities is indicative of underlying unintuitive UI.

My thoughts below:

How chrome dev tools looked at the time this post was authored.

 

My Complaints

 

A mockup of a redesign of chrome dev tools UI that fixes many of the issues