Git Pull Causes a Merge

If you type git pull and expect a fast-forward update, but get a merge instead, don't panic! This usually happens when we're collaborating on a branch with other people, and we've made changes on our local version of a branch, and someone else (or the other you, if you use git to sync between multiple dev platforms) has made changes to the remote version of a branch in the meantime. It also happens really frequently in teams where all commits are to the master branch ... yet another reason to have a decent branching strategy.

All that's happened is something like this:

$ git log --oneline --all --graph --decorate
* 054f163 (HEAD, branch1) Installation instructions for the application
| * 0ce808c (origin/branch1) Fixing template layout
* 927aad9 A random change of 731 to ideas2.txt

Since the last common commit, there are commits on your local branch, and the remote one. You could just let the merge go ahead but there are other options. You could also check out a new branch at this point, reset your tracking branch to the right place and then reapply your changes using cherry-pick or by rebasing and then fast-forward merging your branch. Continue reading

Debugging rst2pdf and pygments

I create my slide decks from ReStructuredText, which is a text markup format. Working this way makes it easy to add into source control, fast to work with, and also accessible since I don't use a mouse or other pointing device so traditional slide deck creation programs are kind of difficult. Text-based wins every time for me. While working on a new slide template, I ran into some difficulties and had to figure out how to inspect what was going on. I seem to struggle with this every time so I am writing my troubleshooting guide here for when I need it next. Continue reading

Code Reviews: Before You Even Run The Code

I do a lot of code reviewing, both in my day job as principal developer and also as an open source maintainer. Sometimes it seems like I read more code than I write! Is that a problem? I'm tempted to say that it isn't. To be a good writer, you must be well-read; I believe that to be a good developer, you need to be code-omnivorous and read as much of other people's code as possible. Code reviews are like little chapters of someone else's code to dip into.

Over time I've developed some particular processes that I find helpful when reviewing code. In particular, I often surprise people at how much review I do before I run the code. Sometimes I grab the branch so that I can use my local diff tools, but I don't actually execute code until I've established some basic facts. This post is a little insight into what's happening in this not-running-the-code-yet zone. Continue reading

Count Changed Lines in Git

I have a favourite set of switches to git log, but today I wanted to answer the question "You deleted how much code today?" so I thought I'd share how I did that

git log --numstat will show you how many lines were added (first column) and removed (next column) per file, kind of a more scientific version of the --stat switch. And if you're thinking of scripting this to gather stats, try it with --oneline as well, it's easier to parse.

Scaling and Sizing with PDFJam

I find myself needing to take a PDF, output it at a specific size, and have the result offset to the top right hand side of the screen. To achieve it, I needed a few new switches to my good friend PDFJam, so I thought I'd share my command!

pdfjam --suffix converted --papersize '{1920px,1080px}' --scale 0.4 --trim "-6cm -1cm 13cm 8cm" slides.pdf

The --suffix is instead of giving an output filename, whatever you feed in ends up with the suffix in its filename. This is very handy because I use this command in a script and only need to pass in one variable. The --papersize isn't a switch I have used before either but you can set exact sizes for the final output which is nice. The --trim switch can also be used to set --clip=true to remove the trimmed space from the document if desired.

I find PDFJam a very handy tool but with not nearly enough blog posts and code snippets around, so I'm dropping my command for future reference (yours as well as mine!).

Vimdiff and Vim to Compare Files

At the moment I'm working on a tricky project where two similar projects diverged. Very similar things happened to them both, but not quite the same things - and now we're merging the codebases to give us as much common code as possible. All this simply serves to set the scene of exactly what I was doing spending a whole day with large code diffs - I had to look up a few things so I thought I'd capture them while I can remember. Continue reading

Todotxt on Android and Ubuntu

I'm a big fan of good tools, however struggle to find products that fit me because there are some key constraints:

  • I use Linux (specifically Ubuntu 14.10)
  • I don't use a pointing device. At all. If I can't use a tool from the keyboard, I can't use it at all (as a side effect, I use keyboard enablers in my browser so if your website has "helper" keyboard shortcuts, I probably can't use that either)
  • My other devices (phone, tablet, work phone) are all android

Taken together, this makes finding tools a challenge - but I've had good experiences with todotxt and the ecosystem around it. Continue reading

Status Check on All Vagrant Machines

Much of the development I do these days uses vagrant machines to make sure that my code is running in the correct environment. This is great, but spinning up too many machines at once can rather stretch the resources of the computer you're running them on - and I keep starting up machines and then forgetting about them!

It turns out that (since vagrant 1.6) you can ask vagrant to tell you which of its machines are running, using the command:

vagrant global-status

Where did all my system resources go? Now I know!

Vim and HTML Tags with the Surround Plugin

Marking up documents is always tedious, and usually there are shortcuts available. My favourite document format tool is Pandoc, literally a box of document-conversion tricks! Today though I was not so lucky so I marked up a plain text file as HTML by hand ... or rather, using my favourite vim tricks so I thought I'd share them.
Continue reading

Git Submodules for Dependent or Common Code

Submodules are one of the most powerful and most mistrusted features in git, at least in the web development part of the internet where I spend my time. I've seen them go horribly wrong, but I've also had teams adopt submodules and have their development process run much more smoothly as a result - so I thought I'd take a moment out of my day to write down the process (and the gotchas) of development with submodules. Continue reading