article
- Choose good names. 😎
- Spot places where knowledge about something does not belong.
- The code won’t be too complex. Because your static analysis tools tell you if your cyclomatic complexity metric is too high.
- Classes and modules will have low coupling and high cohesion. This leads to code that’s more easily testable and has higher reusability than other code.
- If you have an error if explaining comments are missing, you could make sure that your developers take some extra time to make sure code can be easier to understand. Other rules, like variable and method/class/module naming conventions, have the same goal.
-
Invite me to give a workshop on software design and architecture, testing or how to write better code
-
Try to use gamification. This could mean that you publicize the code quality metrics and make it a game to increase the score. The weekly winner gets a price (a half-day off of work?). Better: Make it a team effort. Let them all be winners because it was probably not one person that created all the code in the first place, right?
-
Send them to workshops, conferences or use learning sessions to help them understand how a better/different way to write code would help them with their job.
I sincerely believe that engineers, programmers, developers, coders, and hackers (which one are you?) take pride in their work. They always try to do the best they can. I haven’t yet met a single person who deliberately wrote shitty code. Perhaps it was a byproduct of too little knowledge or experience. But never was it their intent. If you help them level up, they will get better. And your code and products will too.
External forces
I am occupied with learning these days. Learning on my own about visualizations of data among other topics. But also learning about learning. For that I read what other people think about learning. There are many things I have to learn about this whole topic. One thought I saw repeatedly, was about external forces, or limiting factors.
Let me elaborate what I mean by that: There are people that can motivate themselves more easily than others can. They reach their goals or at least try very hard. Others give up more easily when they face some resistance. As always, there are people in the middle between these extremes. You know best which group you belong to. 💪
What has this do with software quality? I am getting there… 😉
I am wondering how external forces could help improve quality. If you need to reach your goal and you don’t belong to the group of highly self-motivated people there are options like hiring a coach. Athletes do that all the time. I pay for a “virtual” coach that guides my running efforts.
How could you hire a “virtual” coach for your coding efforts, for reaching your targets on your software quality metrics? You could hire me or other “real” coaches, of course. But that doesn’t scale too well and might be too expensive.
Again, for some people it is easy enough to use static analysis or linting — a kind of coach in it’s own right — and follow their guidelines. Yet, still there are people that ignore the warnings or guidelines imposed upon them by the tools. Reasons may be a hard deadline or too much workload. How could we offer external forces, limiting factors that help them, guide them, towards doing the right thing?
One solution I can think of is to have a robot not accept your code when it is below standard or ignores guidelines. A robot could be anything that measures and grades your code and reports back to your team. Some tools already offer this, for example GitLab. If you want to merge code that decreases the overal quality metrics, you are not allowed to do so. So that would be one.
Another idea: If you try to commit or merge such code, you need to consult with another developer about the code. Once you worked on it together, the other dev has to enter her secret key, to remove the lock on the merge. This forces you to pair on code more often.
When it comes to teaching there is this saying of the “glass has to be empty (enough).” You cannot pour water into it, when it’s already filled. Said ideas 👆probably won’t work for a team that isn’t aiming for learning and improving.
I will continue to think.
Complex conditionals
The other day we dealt with code coverage and gnarly conditionals. I promised to offer a way to be able to test them properly.
THERE IS NONE.
Ha, what a bad joke. But the real answer might not be better, depending on your point of view. What you have to do is create a table.
(A || B) && C
This is our conditional.
| m | A | B | C | RESULT |
----------------------
| 0 | T | T | T | T |
| 1 | T | F | T | T | x
| 2 | F | F | T | F | x
| 3 | F | T | T | T | x
| 4 | T | T | F | F |
| 5 | T | F | F | F | x
| 6 | F | T | F | F |
| 7 | F | F | F | F |
# m is the test case
# A, B, C are the atomic parts of the conditional
# RESULT is the result of the evaluation of the conditional
For three terms in a conditional, you can have 8 different cases (2^3). You don’t need to test every case. You have to find those cases where switching one term (A, B or C) changes the RESULT. You take those cases and write tests for them. You can ignore the rest as they don’t bring you any new information. For our example these could be the test cases 1, 2, 3, 4. I marked them with an x,
The general rule of thumb is that you can solve this with n + 1 test cases where n is the number of terms.
This technique is called Modified Condition/Decision Coverage or short MC/DC. I like this name, it’s easy to remember 🤘.
It gets harder to do, when one term of the conditional is used more than once (coupled). Another thing to take note of is that depending on the decision statement in the code, it may not be possible to vary the value of the coupled term such that it alone causes the decision outcome to change. You can deal with this by only testing uncoupled atomic decisions. Or you analyse every case where coupling occurs one-by-one. Then you know which ones to use.
You’ll have to do this in the aerospace software industry or where you deal with safety-critical systems.
If you read this far: Congratulations. This is one of the more in-depth topics of testing software. You deserve a 👏 for learning about these things!
Code coverage can be misleading
During the last week, I had two discussions about code coverage. Code coverage is the metric of how many lines of code are covered by your automated test suite. Many test frameworks have built-in ways to measure this. Other times you have to install another tool manually. When you run your tests you then see how many lines are not covered by a test. That means that no test was run where this line of code was evaluated or executed or interpreted.
When you reach 100% code coverage, what then? Are you done? Could you guarantee that there are absolutely no bugs in your code?
If you are tempted to say Yes, or “maybe?" then let me tell you that you are wrong.
Consider this piece of code.
If you write a unit test for this method, the line eval... will be interpreted because of the if emergency at the end. The line is thus covered.
But the code is not covered or tested.
Admittedly, this is a very trivial example that I made up. In reality, there are some more profound things to consider.
If you have complex conditionals you might need a logic table where you compare all possible combinations of the atomic parts of the conditional.
You cannot possibly evaluate this in your head and know whether you checked for every possible, sensible combination. Yet when you cover that line you are at 100% coverage and can go home, right?
So what do you do? Let’s look at this tomorrow.
Quick wins, part 4: YAGNI
We refactored some code yesterday, to move knowledge about an implementation of a function back to where it belonged: Into the function’s class and into the function itself.
Today I want to talk about another topic that often comes up when you are refactoring, or plainly “changing code.”
It happened the other day, during a workshop I was doing on software testing. The participant wanted to apply his new knowledge and write tests for a given JavaScript class. He had written the code a few weeks before we did the workshop. During the hands-on part of the workshop, he wanted to add tests, to make sure everything worked and to make sure that he understood what I had been talking about.
We were lucky in as so far that something happened that usually happens next: He noticed that his code was not easily testable. The design of his class made it harder for him than he would have liked. We talked about the problem, and he noticed the source of it. His class had too many responsibilities. He extracted the code in question into a new service and could then mock the new service when testing his original class. This was good. He was ecstatic. He made progress!
Having gained so much momentum, he went overboard: During his test-design, he wanted to be too clever and tried to write an elaborate test setup which was to be reused between different test runs. It was supposed to be a reusable, parameterizable do-it-all function that could setup the tests just right. With no duplication. In short, it was so much code with so much logic that it would’ve warranted its own tests. And the worst thing? It didn’t work and made trouble for writing his tests.
I was a bit thankful because that gave me the opportunity to tell him:
Premature optimization is the root of all evil.
Perhaps you’ve heard that saying already. Donald Knuth coined this phrase. There’s more to it, but that could be discussed in another email.
Back to my tester. After talking about the problems his function gave him and the difficulty in getting it right he settled for the simple solution: Write your tests. Accept duplication. Keep it simple, use copy & paste if it makes you faster and is more convenient. Write the tests you need and keep them green. And after all that, and only then, refactor your tests to remove duplication where applicable. Don’t try to write the perfect code from the start. Let the design evolve with the help of your tests. Don’t be afraid to make baby steps and don’t expect to have perfect code after the first try.
I hope you liked this series. Perhaps you could take something away from it. If you have questions, let me know.
Tomorrow I’ll be off; it’s a holiday where I live, and I’ll use it to spend time with my family. See you on Monday. 👋
Quick wins, part 3: Keep it local
Yesterday I closed with this idea:
Spot places where knowledge about something does not belong.
What do I mean by that? Sometimes I come across some code that does not read right. I will use a pseudo code example to illustrate:
class Foo
def initialize(bar_service)
@bar_service = bar_service
end
def quux
if @bar_service.greeting == "hello"
@bar_service.greet("goodbye")
else
@bar_service.greet("hello")
end
end
end
class BarService
attr_accessor :greeting
def greet(message)
@greeting = message
end
end
What bothers me with this code? The method quux has too much knowledge about how the @bar_service works. Foo.quux knows that the @bar_service has an instance variable called greeting and at least one specific value it might have ("hello"). It also knows two values that the greet() method might be called with.
Now it happens that this knowledge about how the greeting and greet work, is also spread into other parts of the application. What happens if you need to change something about the greet() method? You have to find every place in your application and update it to reflect the new changes.
This isn’t good.
There are places like this inside many applications. You might need some practice to spot them, but with some practice it becomes easier. For this example I would like to suggest to move all knowledge about how greeting and greet work inside the BarService. Start with the conditional, like this:
class Foo
def initialize(bar_service)
@bar_service = bar_service
end
def quux
@bar_service.greet
end
end
class BarService
attr_accessor :greeting
def greet
if @greeting == "hello"
@greeting = "goodbye"
else
@greeting = "hello"
end
end
end
Now we are free to change the internals of the greet method. We could add a third option or change it completely. The class Foo does not need to change at all. It continues to call greet as if nothing has happened.
One of my overarching topics is testing. A refactoring like this should be covered with tests. Not only do you need tests for the Foo class, but also for how BarService.greet works. And for every part of the app that interacts with either.
Tomorrow we’ll look at another way to do a refactoring.
Quick wins, part 2: Method names revisited
Yesterday, we had the first part of this series on quick wins and simple steps to improve your code quality. It was about naming — specifically variables and method names.
Two things were not 100% right in these examples.
The first error
You might have noticed that my loop examples were written in Ruby code. Yet the method name doSomething was written in camelCase. This is unusual for Ruby code where developers tend to use snake_case for method names.
I did not lint that email. Hence no robot told me about my error. I believe it is a good example of the benefit of automatic linting. This error would have been found. If you read the code and were put off by this naming scheme, you even experienced why conventions and rules are necessary: Because coding by the rules helps developers to focus on the semantics of the code, not the syntax.
The second problem
Do you remember that I wrote about JavaScript loops and gave the classic for loop example? I complained about the i variable and that it should be called iterator. Perhaps you did not like this idea and my example? Let me take a step back for a second.
When naming variables and method names, you have to make sure they “speak.” The names should indicate their meaning and make it easier for another developer to understand the semantics of your code. Yet, when you are fully aware of the problem domain you code deals with, it can happen that you try to be too specific. If you are, you tend to use long, verbose names for variables and methods. An example could be this:
A common value for the allowed length of method names is 30 chars. The above example could be broken into two methods.
The next possible quick win might be to think about the existence of these methods inside the Article class. Verifying and fixing meta tags surely does not need to be done inside this class. If you want to follow the Single Responsibility Principle, you should make sure that the Article class does not have a reason to change, if you decide to change something about verifying and fixing meta tags. Rather the Article class might change when you decide that an article should have a mandatory sub-headline.
Back to the iterator. This name could pass the test for too specific. Only, when i refers to a variable that is declared and initialized outside of the scope of the loop, does it make sense to choose a different name. Or doesn’t it? As always it depends. The classic for loop is taught in almost every book on JavaScript, and it is easily identifiable as to what it is. But there might be reasons to deviate from that, as I indicated above.
Conclusion
To summarize:
Tomorrow we’ll look at another example for 2 and a practical idea of what to do about it.
Quick wins and simple steps for improving the quality of your code
Good software needs good code. If you want to achieve a high quality in what you ship, you need to care for the quality down to each method you write.
I want to use this week to write a small series on techniques and ideas about how to increase your code quality. When I look at code, it is often possible to find spots in the code, where a simple change can be made. In some cases it’s even an easy tweak. Some of these examples will come from the the actual code that I worked on. Others will be created by me, for this series. You won’t see any code from my clients, of course. The only thing I take from them is the inspiration. And money. 🤣
Naming
A good place to start with is to look at variable names. If you have a call to .map() or .each(), then take a look at what you are iterating. Is is a list of Book objects? Then you should call each item that you are iterating what it is, book.
# this is not good
items.map do |i|
i.doSomething
end
# this is better
list_of_books.map do |book|
book.doSomething
end
This would take care of the naming of some variables.
In classic JavaScript loops, you often see a variable called i:
for (i = 0; i < array.length; i++) {
// something happens here
}
Well, what’s this i anyway? If it’s an iterator, why not call it that? Even worse, when you sometimes combine i with a jand a k:
for (i = 1, j = 0, k = 150; i <= 5; i++, j += 30, k -= 30) { /* do work */ }
(This is copied from a SO answer)
I bet you a non-trivial amount of money that you won’t be able to tell me without looking it up what these variables refer to 9 months after you wrote code like that.
Will it take a small amount of extra time to come up with a proper name and use that instead? Probably. Will this extra time be saved every time a(nother) human reads that code? Hell yes!
A possible next step would be to change something about the doSomething() method. What the hell does it do? Why doesn’t it tell us already from its name?
In this case? Because that’s just pseudo-code for you 😜
But please make sure that you use proper and valid names for your methods and variables.
Power Laws
My work as a consultant offers me the opportunity to accompany a team for a certain amount of time. I join them, we work together, and then I leave again. Our time together gets extended, sometimes. This model has the benefit that I get to know a lot of people and teams — and how they work.
Do you know the Pareto principle? It’s also called the power law distribution or the 80/20 rule. A simple explanation would be that 20 percent of the people own 80 percent of the wealth of the whole world, which makes it relatable and understandable. Only that it’s wrong. By now 10% hold 90% of the wealth already. And it’s getting worse. I don’t have any sources on this right now, and I won’t go looking. Because it was only meant as an image of how this works.
Back to my clients…
There is a similar distribution of 80/20 to be found. 80% of software development teams do the same mistakes over and over again. It starts with a new green-field project. A year of development work passes. A lot of code was written. And after a year the team is frustrated with their software again and doesn’t find a way out. This is bad practice.
If you find yourself in these situations, there are ways out of it. With a lot of intrinsic motivation and the ability to learn from mistakes and external sources, you could be able to drag the ship around and sail into the sunset, happily. But there are a lot of rocks under the water that might wreck your boat. An experienced navigator for these waters could prove beneficial.
In my opinion, a good start is to look to industry standards and follow those as well as common best-practices. Find and learn the rules on how other teams work. They might seem strange; you might not understand or like them. But let me tell you something: They way you worked up until here didn’t work and brought you into this mess. Doing things as you’ve always done them won’t help you a bit.
So, don’t be smart. Find rules. Follow the rules. Stick to them and don’t deviate. Re-evaluate in 6 months. It will hurt. It might not be fun. But it will get better.
If you need a pointer, let me know by replying.
Refactoring without a care
Before I get to today’s topic, I would like to say thank you, to you. My little poem yesterday seemed to resonate with you. At first, I planned to write about it and its meaning today. But your responses indicated that it spoke to you. And I wouldn’t want to ruin this with my ramblings about it. So I’ll just finish with: I enjoyed this very much.
Lately, I spent some more time on Twitter. I don’t know how to use Twitter well (enough). I always have trouble with creating threads or topics. But I (re)discovered some very interesting people, sharing their ideas in long threads.
A few days ago I came across @GeePaw Hill. I believe it was because I followed a few tweets by Kent Beck. GeePaw Hill had this thread where he encouraged people to refactor without caring for the application domain, only for the code. You can read the thread here. He even elaborated some more on his blog.
I find the idea fascinating and will continue to think about that.
A neverending story
Back then; I did it; I liked it much; Found it a necessary touch;
Never it challenged, I; then saw; A source without it; didn’t look too raw;
Since then it flows without it well Some purists call it living hell.
A neverending story
Back then; I did it; I liked it much; Found it a necessary touch;
Never it challenged, I; then saw; A source without it; didn’t look too raw;
Since then it flows without it well Some purists call it living hell.
Computer says no
[…] we do have formal rules that we should obey when writing code. A team has rules, and new team members need to learn them before trying to write any code.
That’s what I wrote yesterday. It’s my email so I can write whatever I think is correct. You’ll let me know through your answers if I am wrong.
My friend Tino answered on Friday and asked whether a university degree or certificates might function as a driver’s license. And that is true to a certain degree. I am getting a new certificate these days as well. I hope to complete the exam on Wednesday (ISTQB Advanced Level — Technical Test Analyst).
The obvious difference to a driver’s license? I am not legally required to obtain one before I can start writing code. Tino also said that he’d find it interesting to be (self)tested in current web-standards and best practices. I do believe these tests are valuable. If I come around to create one, I’ll let you know.
Back to the beginning of the email. Why do rules matter to a team? Developers have their style for writing code. Even if there are rules and certain regulations you have to follow, developers still find ways to write code in their unique style. And that’s a good thing. It would be boring otherwise. Still, this style has to obey the rules. Here’s why:
In short: Rules help your team to write code that is maintainable and has low technical debt. This reduces the total costs of ownership. If you only look at the cost of writing the code and delivering the software, the costs might be higher if you follow stricter rules. Over the complete lifecycle of a software (product), the total costs would be lower because of better maintainability and a lower number of defects.
This is already getting long. See you tomorrow with even more thoughts on this topic.
Driving on the left side of the road
We don’t have rules of the road for software development. You don’t have to stop at every red light or keep your speed below a specific limit.
Well, yes. We do have rules. If you write your whole program in only one file, someone will tell you that this is bad. At least I hope that’s the case!
If you only use variable names like x or y, your coworkers will flag this during code review. Perhaps you already have static analysis tools that tell you before your coworkers do?
While we do not have a driver’s license, we do have formal rules that we should obey when writing code. A team has rules, and new team members need to learn them before trying to write any code. Otherwise, it could feel like driving on the wrong side of the road: Driving on the right side of the road feels natural to you if you’ve never done it any differently. But it can have dramatic consequences if everyone else expects you to drive on the left side.
Coding license
Every country I know has an obligatory driving license before you are allowed to drive a car by yourself.
No country I know has an obligatory coding license before you are allowed to code by yourself.
The longer the time that passed between the driving license and the current day, the more reckless and careless drivers have become. What I mean is that new drivers are careful. For the rules, for their passengers, for other cars and people. The longer they drive, the more they bend the rules, pass yellow or red lights, or speed just a tiny bit. Everonye does it, why shouldn’t they do it as well. No one is looking anyway…
I won’t argue for a coding license. It would be fruitless anyway, and it would be too hard to establish a standard. But there so many simple (not easy) wins you could have with the proper knowledge and attitude. So many legacy systems less and so many more successful projects.
When was the last time you compared your skills in coding with other people and had the possibility to spot places you could improve? How do you score your ability anyway? How do you decide what to learn or focus on?
Do you decide these things before you start to code on a project, or do you only find out in hindsight, when issues arise or new features begin to get harder to realize? Do keep a list of problems you identified and make sure you avoid them in the future?
I’ll take the next week to look into this more.
Software rewrites - Does it make sense?
I came across a very interesting article written by Herb Caudill, on different perspectives on rewriting software. He highlights 6 different stories of how a rewrite went. You can read about Basecamp, Netscape Navigator, Gmail, and others.
It is a long article, over 30 minutes according to Medium.com. And I am also sorry for linking to Medium. I don’t like them, and I resent sending them traffic. But this story might be worth it.
Here you go: Lessons from 6 software rewrite stories
NB: I do have experience with software rewrites myself. I took part in two endeavors. One thing was a client application. The legacy app was written in Rails 2 (I believe, it might have been Rails 3) and heavily patched. This made maintenance and feature development quite expensive. We rewrote the software but kept quite close to the original in functionality. The rewrite enabled us to use modern gems and solutions we had created in-house for other clients. This used synergies. It was an ambitious project. In the end, I think it didn’t make too much sense, financially. But I couldn’t be sure about that one.
Another project where I helped on a rewrite concerned frameworks for iOS applications. We had customers that wanted to publish iPad magazines on the App Store. To make it easier for themselves, previous developers had written a custom publishing framework. This framework was reused on every project. It was extendable, reusable and efficient. But it was also difficult to handle and very limiting with regards to layout and design of the magazines. Which was a problem for the clients. So they set out to rewrite this. I joined the company while the project was still in progress. I left 2 years later. The project was still ongoing. The rewritten framework was used in every client project, alongside the older framework. For some features, you had to use the old one, because they weren’t yet supported on the new framework. For other use-cases, you had to use the new framework. Especially for certain pages in the magazine, with new layouts. Yeah, it sucked.
Answering a comment about 'Delete all your tests'
Matthias Berth is a German expert on software delivery and software quality. He politely disagreed with me on the idea that you should delete all your tests.
I decided to call this day “Video Wednesday” and record an answer as a video. I just posted it on LinkedIn, and thought you might like to watch it there.
It even has subtitles 😉
Answering a comment about 'Delete all your tests'
Matthias Berth is a German expert on software delivery and software quality. He politely disagreed with me on the idea that you should delete all your tests.
I decided to call this day “Video Wednesday” and record an answer as a video. I just posted it on LinkedIn, and thought you might like to watch it there.
It even has subtitles 😉
Motivation, or: How to get your coworkers to write better code
How can I get my coworkers to write better code?
We closed with this question, yesterday. If you want to be able to motivate your coworkers to write better code, you have to know where they stand right now. I already wrote a few articles onthis topic. Follow these links, and you’ll get a good idea on what to measure, how and why. You’re welcome.
After reading and measuring and talking with your coworkers, you are still left with the idea of motivating them.
I am good with code and perhaps with words (you decide). Motivation is a “people-topic”. This is psychology. I do know a good book, a classic that you could read: Peopleware: Productive Projects and Teams The contents in the book will help you understand how to build a great team, how to motivate people and understand their goals. You could adapt this knowledge and make them write better code. Other ideas:
2018 State of Code Review Study
81% of respondents who were satisfied with their code review process were also satisfied with the overall quality of their software. Respondents who were not satisfied with their code review process were half as likely to be satisfied in their overall software quality, with only 40% respectively.
This is from a research study done by SmartBear.
This image tells us that the majority things code review is the way to go to increase code quality. This might be true, or it might not. The quality of a review depends 100% on the knowledge, ability to communicate and the time a reviewer takes to dive into the code. Static analysis is way down in second to the last place. Unit testing is right behind code reviews.
I could argue either way. My problem with this study is the term code quality. Code quality to me means that you talk about things like coupling/cohesion, readability, and maintainability, adherence to standards, low bug count. Quality metrics your code exhibits. Code review is not the best tool to increase this metric. Robots and static analysis are. You need impartial tools that hold you to a strict standard. People don’t do this. They are lazy. If you talk about software quality, on the other hand, that’s where you need people. Thinking about and discussing software architecture and design, debating about usability. Fine-tuning the visual design of a product. This is where reviews are the go-to tool for the job.
I guess this distinction was unclear to most participants. That’s a shame.
You can read the study here. I don’t link to their signup form for the study. They ask details like your phone number before you can download it. That’s bad practice, hence the direct link. I’d be happy to hear your thoughts on this. Do you make a distinction between code and software?