Posts tagged ‘clean code’

I’ve been working on this Kata “Gilded Rose” at a few different coding dojos lately. There is even a video of a session I did at the “Tampere Goes Agile” conference recently. In the video, you can see me talking about my Principles of Agile Test Automation, which I have just written about, and updated in my last blog post.

I think these test automation principles are useful to think about when you’re doing the Gilded Rose kata. The basic plot of the Kata is that you’ve just been hired to look after an existing system, and the customer wants a new feature. Having a look at the code, you can see you’re going to want to refactor it a little before adding the new feature, and before you do that, you’re going to want some automated tests.

So the first part of the Kata is to add automated tests to the existing code. You’ve got a requirements document the customer has given you, and you can use it to identify test cases. You’ve also got the code which you can read and execute and work out what it does. The customer is happily using the code in production right now, so you can assume that the behaviour it has is the behaviour they want to keep, whatever it says in the requirements document. (hint!)

Warning – spoilers lie ahead! You should probably try the Gilded Rose kata for yourself before reading on!

When I’ve done this exercise with various groups, I’ve spent a lot of time discussing with people how to make their test cases really readable, and express the requirements clearly, and at the same time useful as regression protection when refactoring the code later.

When you design a test suite you have two main aims – to help you understand what the code should do, (and what it does now), and protection from regression failures when you update it. It can be a bit tricky to do both with the same test suite. If you focus solely on describing the requirements in an executable way, you tend to miss edge cases and there are gaps in the regression protection. If you focus only on regression protection, you’ll spend time analysing the edge cases, and measuring code coverage to see how well you’re doing, but the test cases can become quite hard to read and understand.

You can see for yourself by comparing this test case by Bobby Johnson with this text-based approval test. (It was written by several people at a GothPy meeting). Bobby’s test case is extremely readable and expresses the requirements clearly. He’s done pretty well on the edge cases, but I think he’s missing one or two*. With the text-based approval tests, it’s not so easy to understand what the underlying business rules are, although the regression protection is very good.

When I do this kata with a group, we spend some time discussing the various test cases we’ve come up with, and showing them on the projector. When we did this last week at the Booster Conference, people commented that showing these different test cases had given them a better understanding of “readability” and “regression protection”, and many went on to improve their test suites.

Once you’re reasonably happy with your test suite, the next task is to do the refactoring and add the new feature. How useful are your test cases for regression protection? It’s very easy to make refactoring mistakes in this kata, and you will be testing your tests! You may discover while refactoring that there are more test cases that you want to add. Version control can be pretty useful, so you can run the new test cases against the original code.

There’s also an interesting restriction on your refactoring options – the “Item” class is owned by a nasty-sounding goblin and he doesn’t want you to change his code, so if you do, you have to be prepared for some serious consequences! When comparing refactored solutions at the end of the dojo, this is often an interesting discussion point – did you change the Item class? Is your new design so great that you’re prepared to argue with the goblin for it?!

I havn’t tried this, but I would actually like to try running the text-based approval test against all the refactored solutions at the end of the coding dojo, as input to the retrospective. I think this test covers all the edge cases very well, and would reveal any refactoring mistakes that were not caught by the tests people had developed themselves. That would be interesting feedback to have!

If you havn’t tried the Gilded Rose kata yourself, I do recommend it for practicing writing good test cases. I’d be happy to get a pull request from you if you want to translate the exercise into your favourite programming language, or you can do it in the original C#, as Bobby suggests.

If you’re interested in taking part in a coding dojo with me, I’ll be at several conferences later this year: ACCU in Bristol, XP2013 in Vienna and Test Automation Day in the Netherlands.

* I believe he’s missing a check that the quality of backstage passes doesn’t increase past 50

This Code Kata is included in my new book “The Coding Dojo Handbook”, currently published as a work-in-progress on LeanPub.com. You can also download starting code and these instructions from my github page.

As a Health Insurer,
I want to be able to search for patients who have a medicine clash,
So that I can alert their doctors and get their prescriptions changed.

Health Insurance companies don’t always get such good press, but in this case, they actually do have your best interests at heart. Some medicines interact in unfortunate ways when they get into your body at the same time, and your doctor isn’t always alert enough to spot the clash when writing your prescriptions. Sometimes, medicine interactions are only identified years after the medicines become widely used, and your doctor might not be completely up to date. Your Health Insurer certainly wants you to stay healthy, so discovering a customers has a medicine clash and getting it corrected is good for business, and good for you!

For this Kata, you have a recently discovered medicine clash, and you want to look through a database of patient medicine and prescription records, to find if any need to be alerted to the problem. Create a “Patient” class, with a method “Clash” that takes as arguments a list of medicines, and how many days before today to consider, (defaults to the last 90 days). It should return a collection of days on which all the medicines were being taken during this time.

If you like, you can also create a visualization of the clash, something like this:

medicine_clash

Data Format

You can assume the data is in a database, which is accessed in the code via an object oriented domain model. The domain model is large and complex, but for this problem you can ignore all but the following entities and attributes:

TDDStatesMoves_003

In words, this shows that each Patient has a list of Medicines. Each Medicine has a list of Prescriptions. Each Prescription has a dispense date and a number of days supply.

You can assume:

  • Patients start taking the medicine on the dispense date.
  • The “days supply” tells you how many days they continue to take the medicine after the dispense date.
  • If they have two overlapping prescriptions for the same medicine, they stop taking the earlier one. Imagine they have mislaid the medicine they got from the first prescription when they start on the second prescription.

When you’ve tried the Kata for yourself

Then you might be interested in reviewing the sample solution I’ve put up on my github page. I find this code interesting because it is seemingly well written. The methods are short with thought-through names, and there are lots of unit tests. I also find it very difficult to follow. What do you think?

The biology of medicine clashes*

When you take a pill of medicine, the active substance will be absorbed through the lining of the gut, and enter your bloodstream. That means it will be taken all over your body, and can do its work. For example, if you take a headache pill, the active substance in the drug will be taken by your blood to where it can block your pain receptors. At the same time, there are enzymes at work in your liver, which break down medicinal substances they find in your bloodstream. Eventually all the medicine will be removed, so you have to take another pill if you want the effects to continue.

In the liver, there are several different enzymes working, and they are specialized in breaking down different substances. For example, the “CYP 2C9” enzyme will break down ibuprofen, the active ingredient in many headache pills. The trouble is, there are other medicines which will stop particular enzymes from doing their work, which can lead to an overdose or other ill effects.

One example is the clash between fluoxetine and codeine. Fluoxetine is known by its trade name “Prozac”, and is often taken for depression. Codeine is another ingredient used in headache pills, and is actually a “pro-drug”, so it works slightly differently. Codeine needs to be broken down in the liver by the enzyme “CYP 2D6” into the active substance, morphine, before it will do anything. Fluoxetine has the effect of blocking “CYP 2D6”, so if you take the two medicines together, you won’t get much painkilling effect from the codeine. That could be depressing!

The solution to the problem is to take a different painkiller – one that’s not affected by that liver enzyme. Simply switch codeine for ibuprofen, and you should be be a little happier.

* With thanks to Sara Sjöberg for helping me with this section

A little while back I was back in Stockholm facilitating another Code Retreat, (see previous post), this time as part of Global Day of Code Retreat, (GDCR). (Take a look at Corey Haines’ site for loads of information about this global event that comprised meetings in over 90 cities worldwide, with over 2000 developers attending.)

I think the coding community could really do with more people who know how to do TDD and think about good design, so I’m generally pretty encouraged by the success of this event. I do feel a bit disappointed about some aspects of the day though, and this post is my attempt to outline what I think could be improved.

I spent most of the Global Day of Code Retreat walking around looking over people’s shoulders and giving them feedback on the state of their code and tests. I noticed that very few pairs got anywhere close to solving the problem before they deleted the code at the end of each 45 minute session. Corey says that this is very much by design. You know you don’t have time to solve the problem, so you can de-stress: no-one will demand delivery of anything. You can concentrate on just writing good tests and code.

In between coding sessions, I spent quite a lot of effort reminding people about simple design, SOLID principles, and how to do TDD (in terms of states and moves). Unfortunately I found people rarely wrote enough code for any of these ideas to really be applicable, and TDD wan’t always helping people.

I saw a lot of solutions that started with the “Cell” class, that had an x and y coordinate, and a boolean to say whether it was alive or not. Then people tended to add a “void tick(int liveNeighbourCount)” method, and start to implement code that would follow the four rules of Conway’s Game of Life to work out if the cell should flip the state of its boolean or not. At some point they would create a “World” class that would hold all the cells, and “tick()” them. Or some variant of that. Then, (generally when the 45 minutes were running out), people started trying to find a data structure to hold the cells in, and some way to find out which were neighbours with each other. Not many questioned whether they actually needed a Cell class in the first place.

Everyone at the code retreat deleted their code afterwards, of course, but you can see an example of a variant on this kind of design by Ryan Bigg here (a work in progress, he has a screencast too).

Of course, as facilitator I spent a fair amount of time trying to ask the kind of questions that would push people to reevaluate their approach. I had partial success, I guess. Overall though, I came away feeling a bit disillusioned, and wanting to improve my facilitation so that people would learn more about using TDD to actually solve problems.

At the final retrospective of the day, everyone seemed to be very positive about the event, and most people said they learnt more about pair programming, TDD, and the language and tools they were working with. We all had fun. (If you read Swedish, Peter Lind wrote up the retrospective in Valtech’s blog) This is great, but could we tweak the format to encourage even more learning?

I think to solve Conway’s Game of Life adequately, you need to find a good datastructure to represent the cells, and an efficient algorithm to “tick” to the next generation. Just having well named classes and methods, although a good idea, probably won’t be enough.

For me, TDD is a good method for designing code when you already mostly know what you’re doing. I don’t think it’s a good method for discovering algorithms. I’m reminded of the debate a few years back when Peter Norvig posted an excellent Sudoku solver (here) and people thought it was much better than Ron Jeffries’ TDD solution to the same problem (here). Peter was later interviewed about whether this proved that TDD was not useful. Dr Norvig said he didn’t think that it proved much about TDD at all, since

“you can test all you want and if you don’t know how to approach the problem, you’re not going to get a solution”
(from Peter Siebel’s book “Coders At Work”, an extract of which is available in his blog)

I felt that most of the coders at the code retreat were messing around without actually knowing how to solve the problem. They played with syntax and names and styles of tests without ever writing enough code to tell whether their tests were driving a design that would ultimately solve the problem.

Following the GDCR, I held a coding dojo where I experimented with the format a little. I only had time to get the participants do two 45 minute coding sessions on the Game of Life problem. At the start, as a group we discussed the Game of Life problem, much as Corey recommends for a Code Retreat introduction. However, in addition, I explained my favoured approach to a solution – the data structure and algorithm I like to use. I immediately saw that they started their TDD sessions with tests and classes that could lead somewhere. I feel that if they had continued coding for longer, they should have ended up with a decent solution. Hopefully it would also have been possible to refactor it from one datastructure to another, and to switch elements of the algorithm without breaking most of the tests.

I think this is one way to improve the code retreat. Just give people more clues at the outset as to how to tackle the problem. In real life when you sit down to do TDD you’ll often already know how to solve similar problems. This would be a way for the facilitator to give everyone a leg-up if they havn’t worked on any rule-based games involving a 2D infinite grid before.

Rather than just explaining a good solution up front, we could spend the first session doing a “Spike Solution”. This is one of the practices of XP:

“the idea is just to drive through the entire problem in one blow, not to craft the perfect solution first time out.”
From “Extreme Programming Installed” by Jeffries, Anderson, Hendrickson, p41

Basically, you hack around without writing any tests or polishing your design, until you understand the problem well enough to know how you plan to solve it. Then you throw your spike code away, and start over with TDD.

Spending the first 45 minute session spiking would enable people to learn more about the problem space in a shorter amount of time than you generally do with TDD. By dropping the requirement to write tests or good names or avoid code smells, you could hopefully hack together more alternatives, and maybe find out for yourself what would make a good data structure for easily enumerating neighbouring cells.

So the next time I run a code retreat, I think I’ll start with a “spiking” session and encourage people to just optimize for learning about the problem, not beautiful code. Then after that maybe I’ll sketch out my favourite algorithm, in case they didn’t come up with anything by themselves that they want to pursue. Then in the second session we could start with TDD in earnest.

I always say that the code you end up with from doing a Kata is not half as interesting as the route you took to get there. To this end I’ve published a screencast of myself doing the Game of Life Kata in Python. (The code I end up with is also published, here). I’m hoping that people might want to prepare for a Code Retreat by watching it. It could be an approach they try to emulate, improve on or criticise. On the other hand, showing my best solution like this is probably breaking the neutrality of how a code retreat facilitator is supposed to behave. I don’t think Corey has ever published a solution to this kata, and there’s probably a reason for that.

I have to confess, I already broke all the rules of being a facilitator, when I spent the last session of the Global Day of Code Retreat actually coding. There was someone there who really wanted to do Python, and no-one else seemed to want to pair with him. So I succombed. In 45 minutes we very nearly had a working solution, mostly because I had hacked around and practiced how to do it several times before. It felt good. I think more people should experience the satisfaction of actually completing a useful piece of code using TDD at a Code Retreat.

Programmers have a vested interest in making sure the software they create does what they think it does. When I’m coding I prefer to work in the context of feedback from automated tests, that help me to keep track of what works and how far I’ve got. I’ve written before about Test Driven Development, (TDD). In this article I’d like to explain some of the main features of Text-Based Testing. It’s a variant on TDD, perhaps more suited to the functional level than unit tests, and which I’ve found powerful and productive to use.


The basic idea
You get your program to produce a plain text file that documents all the important things that it does. A log, if you will. You run the program and store this text as a “golden copy” of the output. You create from this a Text-Based Test with a descriptive name, any inputs you gave to the program, and the golden copy of the textual output.

You make some changes to your program, and you run it again, gathering the new text produced. You compare the text with the golden copy, and if they are identical, the test passes. If the there is a difference, the test fails. If you look at the diff, and you like the new text better than the old text, you update your golden copy, and the test is passing once again.

Tool Support
Text-Based Testing is a simple idea, and in fact many people do it already in their unit tests. AssertEquals(String expected, String actual) is actually a form of it. You often create the “expected” string based on the actual output of the program, (although purists will write the whole assert before they execute the test).

Most unit test tools these days give you a nice diff even on multi-line strings. For example:

download
download (1)

Which is a failing text-based test using JUnit.

Once your strings get very long, to the scale of whole log files, even multi-line diffs aren’t really enough. You get datestamps, process ids and other stuff that changes every run, hashmaps with indeterminate order, etc. It gets tedious to deal with all this on a test-by-test basis.

My husband, Geoff Bache, has created a tool called “TextTest” to support Text-Based testing. Amongst other things, it helps you organize and run your text-based tests, and filter the text before you compare it. It’s free, open source, and of course used to test itself. (Eats own dog food!) TextTest is used extensively within Jeppesen Systems, (Geoff works for them, and they support development), and I’ve used it too on various projects in other organizations.

In the rest of this article I’ll look at some of the main implications of using a Text-Based Testing approach, and some of my experiences.

Little code per test
The biggest advantage of the approach, is that you tend to write very little unique code for each test. You generally access the application through a public interface as a user would, often a command line interface or (web)service call. You then create many tests by for example varying the command line options or request contents. This reduces test maintenance work, since you have less test code to worry about, and the public API of your program should change relatively infrequently.

Legacy code
Text-Based Testing is obviously a regression testing technique. You’re checking the code still does what it did before, by checking the log is the same. So these tests are perfect for refactoring. As you move around the code, the log statements move too, and your tests stay green, (so long as you don’t make any mistakes!) In most systems, it’s cheap and risk-free to add log statements, no matter how horribly gnarly the design is. So text-based testing is an easy way to get some initial tests in place to lean on while refactoring. I’ve used it this way fairly successfully to get legacy code under control, particularly if the code already produces a meaningful log or textual output.


No help with your design
I just told you how good Text-Based Testing is with Legacy code. But actually these tests give you very little help with the internal design of your program. With normal TDD, the activity of creating unit tests at least forces you to decompose your design into units, and if you do it well, you’ll find these tests giving you all sorts of feedback about your design. Text-Based tests don’t. Log statements don’t care if they’re in the middle of a long horrible method or if they’re spread around several smaller ones. So you have to get feedback on your design some other way.

I usually work with TDD at the unit level in combination with Text-Based tests at the functional level. I think it gives me the best of both worlds.

Log statements and readability
Some people complain that log statements reduce the readability of their code and don’t like to add any at all. They seem to be out of fashion, just like comments. The idea is that all the important ideas should be expressed in the class and method names, and logs and comments just clutter up the important stuff. I agree to an extent, you can definitely over-use logs and comments. I think a few well placed ones can make all the difference though. For Text-Based Testing purposes, you don’t want a log that is megabytes and megabytes of junk, listing every time you enter and leave every method, and the values of every variable. That’s going to seriously hinder your refactoring, apart from being a nightmare to store and update.

What we’re talking about here is targeted log statements at the points when something important happens, that we want to make sure should continue happening. You can think about it like the asserts you make in unit tests. You don’t assert everything, just what’s important. In my experience less than two percent of the lines of code end up being log statements, and if anything, they increase readability.

Text-Based tests are completed after the code
In normal TDD you write the test first, and thereby set up a mini pull system for the functionality you need. It’s lean, it forces you to focus on the problem you’re trying to solve before you solve it, and starts giving you feedback before you commit to an implementation. With Text-Based Testing, you often find it’s too much work the specify the log up front. It’s much easier to wait until you’ve implemented the feature, run the test, and save the log afterwards.

So your tests usually aren’t completed until after the code they test, unlike in normal TDD. Having said that, I would argue that you can still do a form of TDD with Text-Based Tests. I’d normally create the half the test before the code. I name the test, and find suitable inputs that should provoke the behaviour I need to implement in the system. The test will fail the first time I run it. In this way I think I get many of the benefits of TDD, but only actually pin down the exact assertion once the functionality is working.

“Expert Reads Output” Antipattern
If you’re relying on a diff in the logs to tell you when your program is broken, you had better have good logs! But who decides what to log? Who checks the “golden copy”? Usually it is the person creating the test, who should look through the log and check everything is in order the first time. Of course, after a test is created, every time it fails you have to make a decision whether to update the golden copy of the log. You might make a mistake. There’s a well known antipattern called “Expert Reads Output” which basically says that you shouldn’t rely on having someone check the results of your tests by eye.

This is actually a problem with any automated testing approach – someone has to make a judgement about what to do when a test fails – whether the test is wrong or there’s a bug in the application. With Text-Based Testing you might have a larger quantity of text to read through compared with other approaches, or maybe not. If you have human-readable, concise, targeted log statements and good tools for working with them, it goes a long way. You need a good diff tool, version control, and some way of grouping similar changes. It’s also useful to have some sanity checks. For example TextTest can easily search for regular expressions in the log and warn you if you try to save a golden copy containing a stack trace for example.

In my experience, you do need to update the golden copy quite often. I think this is one of the key skills with a Text-Based Testing approach. You have to learn to write good logs, and to be disciplined about either doing refactoring or adding functionality, not both at the same time. If you’re refactoring and the logs change, you need to be able to quickly recognize if it’s ok, or if you made a mistake. Similarly, if you add new functionality and no logs change, that could be a problem.

Agile Tests Manage Behaviour
When you create a unit test, you end with an Assert statement. This is supposed to be some kind of universal truth that should always be valid, or else there is a big problem. Particularly for functional level tests, it can be hard to find these kinds of invariants. What is correct today might be updated next week when the market moves or the product owner changes their mind. With Text-Based Testing you have an opportunity to quickly and easily update the golden copy every time the test “fails”. This makes your tests much more about keeping control of what your app does over time, and less about rewriting assert statements.

Text-Based Testing grew up in the domain of optimizing logistics planning. In this domain there is no “correct” answer you can predict in advance and assert. Planning problems that are interesting to solve are far too complex for a complete mathematical analysis, and the code relies on heuristics and fancy algorithms to come up with better and better solutions. So Text-Based Testing makes it easy to spot when the test produces a different plan from before, and use it as the new baseline if it’s an improvement.

I think generally it leads to more “agile” tests. They can easily respond to changes in the business requirements.

Conclusions
There is undoubtedly a lot more to be said about Text-Based Testing. I havn’t mentioned text-based mocking, data-driven vs workflow testing, or how to handle databases and GUIs – all relevant topics. I hope this article has given you a flavour of how it’s different from ordinary TDD, though. I’ve found that good tool support is pretty essential to making Text-Based Testing work well, and that it’s a particularly good technique for handling legacy code, although not exclusively. I like the approach because it minimizes the amount of code per test, and makes it easy to keep the tests in sync with the current behaviour of the system.

 

I’m speaking next week at ScanDev on Tour in Stockholm on the subject of “Software Development Craftsmanship”, and as part of my research I read both “The Clean Coder” by Robert C. Martin and “Apprenticeship Patterns” by Dave Hoover & Adewale Oshineye. These are very different books, but both aimed at less experienced software developers who want to learn about what it means to be a professional in the field. In this article I’d like to review them side by side. First some text from each preface on what the authors think the books are about:

Apprenticeship Patterns

“This book should help you through the tough decisions you face as a newcomer to the field of professional software development. “ (preface xi)

The Clean Coder

“This book is about software professionalism. It contains a lot of pragmatic advice” (preface xxii)

The Content
Both books contain a lot of personal stories and anecdotes from the authors’ careers, and begin with a short autobiography. Some of the advice is also similar. Both advise you to practice with “Kata” exercises, to read widely and to find suitable mentors. I think that’s mostly where the similarities end though.

Dave and Ade don’t say much about how to handle unreasonable managers imposing impossible deadlines. Bob Martin devotes a several chapters to this kind of issue, handling pressure, time management, estimation, making committments etc.

Dave and Ade talk more about how to get yourself into situations optimized for learning and progress in your career. They advise you to “Be the worst”, “Find mentors”, seek “Kindred Spirits”. In other words, join a team where you’re the least skilled but you’ll be taught, look for mentors in many places, and get involved in the community.

Bob talks about a lot of specific practices and has detailed advice. He mentions “… pairing is the most efficient way to solve a problem” (p164) Later in the chapter he suggests the optimal composition of job roles in a gelled team. (p169) He also has some advice about how to successfully argue with your boss and go over their head when necessary (p35).

The Advice
Those few example perhaps illustrate that these two books are miles apart when it comes to writing style, approach and world view. Dave&Ade have clearly spent a lot of time talking with other professionals about their material, acting on feedback and testing their ideas for validity in real situations. The book is highly collaborative and while full of advice, is not prescriptive.

Bob Martin on the other hand loves to be specific, provocative and extreme in his advice. “QA should find nothing.”(p114) “You should plan on working 60 hours per week.” (p16) “Avoid the Zone.” (p62) “The jury is in! … TDD works” (p79) These are some of his more suprising pieces of advice, which I think are actually fairly doubtful propositions when taken to extremes like this. Mixed in are more reasonable statements. “You do not have to attend every meeting to which you are invited” (p123) “The professional developer is calm and decisive under pressure”. (p150)

The way everything is presented as black-and-white, do-or-do-not-there-is-no-try is actually pretty wearing after a while. He does it to try to make you think, as a rhetorical device, to promote healthy discussion. I think it all too easily leads the reader to throw the baby out with the bathwater. I can’t accept one of his recommendations, so I throw them all out.

Some of Dave&Ade’s advice is actually just as hard to put into practice. Each of their patterns is followed by a call to action. Things like re-implementing a program you’ve written in an imperative language in a functional language (p21). Join or start a user group (p65). Solve the same coding exercise once a week for the next four weeks (p79). None of these things is particularly easy to do, but they seem to me to be interesting and useful challenges.


Collaboration
Bob has also clearly not collaborated very widely when preparing his material. One part that particularly sticks out for me is a footnote on page 75:

“I had a wonderful conversation with @desi (Desi McAdam, founder of DevChix) about what motivates women programmers. I told her that when I got a program working, it was like slaying the great beast. She told me that for her and other women she had spoken to, the act of writing code was an act of nurturing creation.” (footnote, p75)

Has he ever actually run his “programming is slaying a great beast” thing past any other male programmers? Let me qualify that – non-fantasy-role-playing male programmers? Thought not. This is in enormous contrast to Dave&Ade, whose book is full of stories from other people backing up their claims.

Stories
Bob’s book is full of stories from his own career, and he is very honest and open about his failures. This is a very brave thing to do, and I have a great deal of respect for him for doing so. It’s also really interesting to hear about the history of what life was like when computers filled a room and people used punch cards to program them. Dave&Ades stories are less compelling and not always as well written.

Bob’s book is not just about his professional life, he shares his likes and dislikes. He reccommends cycling or walking to recharge your energy, or “focus-manna” as he calls it, (p127). Reading science fiction as a cure for writer’s block. (p66) Listening to “The Wall” while coding could be bad for your design. (p63) When describing “Master” programmers he likens them to Scotty from Star Trek. (p182)

All this is very cute and gives you a more rounded picture of what software professionalism is about. Maybe. Actually it really puts me off the idea. I know a lot of software developers like science fiction and fantasy role playing, but it really isn’t mandatory. He usually says that you may have other preferences, and you don’t have to do like he does, but I just don’t think it helps all that much. The rest of the book is highly dogmatic about what you should and shouldn’t do, and it kind of rubs off.

Conclusions
The bottom line is, I wouldn’t reccommend “The Clean Coder” to any young inexperienced software developer, particularly not if she were a woman. There is too much of it written from a foreign culture, in a demanding tone, propounding overly extreme behaviour. The interesting stories and good pieces of advice are drowned out.

On the other hand, I would recommend “Apprenticeship Patterns”. I think it is humbly written and anchored in real experience from a range of people. I agree with them when they say you need to read it twice to understand it. The first time to get an overview, the second time to understand how the patterns connect. It’s not as easy to read as it might be. But still, I think the content is interesting, and it gives a good introduction to what being a professional software craftsman is about, and how to get there.