After writing a lot of metrics for a project in a previous life, not adding any support for Prometheus makes me feel nervous of deploying my code in production.
2. Tests are good, integration tests are gooder.
I'm currently writing tests for a single module only (e.g., only tests for the "view" layer). It gives me some idea of what is right and what is wrong, but in no way I feel those tests say my code is doing what it should do.
3. Tests make better APIs
We build stuff in layers. Tests allow use to see how the API of a layer behaves and we can make better APIs by just checking our struggles writing tests.
4. Future thinking is future trashing
Solve the problem at hand. Don't think "We can do this in a more general way and, in the future, it will be easier to add more". Adding more will never come and you'll have to deal with a pile of trash.
Solve one problem, then solve the next. A patter of problem will emerge -- or not.
5. Code reviews are for architecture, not style
Do not complain about a misplaced semi-colon or a "missing space before parenthesis" in a code review. That's not the forum for this -- unless you found an architectural problem, then you can point both.
5 1/2. Code formatting tools are ok, but are no silver bullet
Computers are very flexible into reading code, but humans are not.
(I may even say that, if the tool is moving a lot of your code, there may be a real architecture problem with your code.)
6. Documentation is a love letter to your future self
Yeah, it's tiring to write the damn documentation on every freaking function, but your future self will thank you for letting the code explained on what it's doing.
6 1/3 The documentation of a function is its contract
The documentation should reflect the code; if it doesn't, you have a problem with your code, not your documentation.
6 2/3. Documentation with an "and" means you're doing it wrong
A function should do one thing and one thing only. If you have to add an "and" to its description, it probably means the function is doing two things and you should break it apart.
6 3/3. Good languages come with integrated documentation
If the language comes with its own way of documenting functions/classes/modules/whatever and it comes with even the simplest doc generator, you can be sure all the language things and libraries will have a good documentation.
But languages with no integrated documentation will most of the time have bad documentation.
7. When it is time to stop, it is time to stop
Learn when you can't code anymore. Learn when you can't process things anymore. Don't push beyond it, it will just make things worse in the future.
8. A language is much more than a language
A programming language is that thing that you write and make things "go". But it has much more beyond special words: It has a build system, it has a dependency control system, it has a way of making tools/libraries/frameworks interact, it has a community, it has a way of dealing with people.
Don't pick languages just 'cause they easier to use.
9. Code of conduct protect _you_, not _them_
When you're beginning with any language/library/framework, check their CoC; they will protect _you_ from being harassed for not immediately getting what is going on instead of blocking you from telling them what you think.
(Addendum: Most of the time, people against CoCs are the ones that want to break it in the first place.)
10. Learn to say no
Sometimes, you'll have to say no: No, I can't do it; no, it can't be made in this time; no, I don't feel capable of doing this; no, I don't feel comfortable writing this.
11. You're responsible for the use of your code
This is hard. Very very hard. It's the difference between "freedom" and "responsibility".
There is nothing wrong in writing, for example, a software to capture people's faces and detect their ethnicity, but you have to think about what that will be used on.
@juliobiason At the same time I have to argue that you might have to allow for some bad usage in order to get the most good usage out of your software.
So while I don't disagree with having the best, most positive, impact you can, it does worry me for programmers to be blamed for how their software is used.
@juliobiason There is a path you can take which (depending on who you ask) isn't against free software. It certainly meets the definitions, and some nuance in Stallman's speeches.
If you're worried enough about your software falling into the wrong hands you don't have to publish it publically. In that way you can mostly decide who gets access to your software whilst still giving those people full software freedom over that program.
For people who care about, support, or build Free, Libre, and Open Source Software (FLOSS).