2 shortcuts that make referencing code easy in GitHub PRs & Issues

Nick Ang — Wed, 13 Apr 2022 15:59:49 +0000

There are two parts to this:

know the command to copy relative file path in your IDE
know the command to launch "go to file" on a GitHub repo

`Cmd Shift P` in Visual Studio Code

I mostly use VS Code, which comes with a wonderful command palette that you can summon up with Cmd Shift P on a Mac. Once summoned, I type "relative" > select File: Copy Relative Path of Active File > hit enter.

Now that I have the relative path, I need to navigate to the corresponding page on GitHub that displays this page.

Just `T` in a GitHub repo

I open the relevant GitHub repo and simply hit T on my keyboard to launch the "Go to file" functionality:

And you guessed it: Cmd V to paste, hit enter, and you're at the right page on GitHub!

Single or multi-line highlights in GitHub

With those two nifty shortcuts, I've gotten to the right page very quickly. Now all that's left to do is to somehow refer to one or multiple lines of code.

GitHub makes this easy:

click the starting line number of the code you're interested in
hold shift
click ending line number
copy the URL, which has changed based on your clicks

Pro tip: hit Y after selecting the relevant line(s) of code to generate a snapshot of the code you've selected. If you don't do this, there's a chance that you may be referencing the main branch's code by line number, which could refer to something else in the future. The snapshot prevents this by referring to a specific commit.

Now I can paste this URL anywhere in GitHub's commenting surfaces like Pull Requests, Issues, or comments and it will either show up as a link or a rich preview.

What I haven't figured out is why I sometimes get a rich preview and other times it shows up only as a hyperlink. If you know, please comment on this so I can learn. I love those rich previews!

An easy way to automate running Rails test (or any command) on file changes

Nick Ang — Tue, 12 Apr 2022 19:52:15 +0000

To my dismay, I realised today while going through unit testing in Agile Web Development with Rails 6 by Ruby, Copeland & Thomas that the Rails CLI does not ship with a --watch option.

It seems like a pretty jarring piece of missing functionality and I still don't know why it's not built into the CLI, so I posted a question in the Rails forum to ask for context, for a start. Let's see how that goes.

Jest CLI has it out of the box

Having used Jest CLI for running tests before, I was used to being able to do this:

$ jest --watchAll

... and have the CLI handle watching files for changes and re-running relevant tests.

But as I've had to use Rails more recently, and I dug into why this was missing from the Rails CLI, I realised that "running relevant tests based on file changes" is actually quite complex. For example, if I changed a method, how should the watcher communicate to the test runner about which tests to re-run (rather than, say, re-running all tests)?

But that's a bit outside of the scope of this post. I brought it up just as a way of doing a head-nod to the complexity behind something like this.

Enter `entr`

Anyway, as I sat at my desk thinking about how to make my TDD-ish (test driven development) workflow easier, I realised that perhaps 50 percent of the usefulness of an automated test runner comes from re-running all tests in a particular test file if it has just been saved.

For that, I learned today that there's a nice command line package called entr that you can install with homebrew (macOS).

Here's how I used it to re-run rails tests based on changes to any file in the /test directory:

$ cd rails-app
$ find ./test -name '*.rb' | entr -s 'rails test'

This will re-run all tests whenever any test file has been re-saved (regardless of whether an actual modification was made). A great first step!

There are gems for that

Just a quick note here that what I mentioned is just one of many ways to achieve the same thing. In fact, what I wrote is less convenient if you need to have this available to everyone in a team rather than just for yourself.

There's a video dated back to 2011 posted in RailsCast about how to use the guard gem to watch files and run tests. This is probably a better approach if you want to implement test runner automation for a team. There is a boatload of other gems that have slightly different implementations but provide similar functionality - you can see them here on ruby-toolbox.

DEV Community: Nick Ang