## }

Would I recommend Emacs as a writing environment? I don’t know. It works for me, mostly thanks to org-roam. And after 5 years of thou shalt not lose weeks of configuring Emacs, I am occasionally making small tweaks.

Admittedly, these tweaks sometimes are things that should just work out of the box (TM). For instance, I can drag and drop an image (on my mac, at least) in an org-mode file, and then I get to choose how the image should be linked to the document. And then I can see it.

But of course I mean for some reason this does not work in markdown-mode. Luckily someone else solved this problem before me.. And found that markdown mode is extensible in how it looks for files.

But what does this have to do with shaving yaks, you wonder? Well, I was annoyed that I could not drag and drop images, displaying images was something the author figured out first, and used as part of a solution in dropping images.

I have been muddling through, and was reminded I have that problem too. But then I was stuck. I hate thinking about paths on my computer. And for some silly reason, I made this blog in the same way as Jekyll and other static site generators - the images are nowhere near the blog posts. I should fix that, but not on a hot friday when I’m recovering from successful, but intensive, new work.

This post helpfully explains how to find the right function, and what to do. And I have a link to an image in my previous post that will of course not show in `markdown-mode`. Staring at the screen for a while, it hit me.

## An example would be handy right about now

So I copied the image link, had a look at my directory structure, enabled images (yes, that is disabled by default. I guess a distraction-free writing environment requires the purity of no man-made images). And then still saw nothing, because I forgot the `static` part of the path. But this was quick iteration, no code or tests were harmed in the making of this example:

    ![Hand drawn state diagram, transcribed below in 'Inline session transcript' as tables and part mermaid diagram.](/images/blog/2026/tdd-state-diagram-john-jagger.jpeg)

    ![what inline image location should be](../../../static/images/blog/2026/tdd-state-diagram-john-jagger.jpeg)

Now I can go back to the joy of copy-paste-modifying the code from the blogpost with my very own path.

## A test would be handy right about now

I figured I could hack this path only for my blog, and use a local configuration. After copy-pasting the code, it was time, for, le sigh modify. I could let my animatronic rubber duck do it, but I have decided to better understand my emacs mods, so doing it by hand today.

There is a `substring` call that I don’t need - my example shows that blog post and images are both under `priv`. So I need a bunch of `..` or be clever and use the git project root. Since my example with `..` works, we’ll make it work and then maybe make it right.

But I don’t often write tests. And there was an error in it, so going straight to an emacs lisp file was too big a step.

## Taking a step back, literate programming to the rescue

In org mode I can have my function and a call for an example in a code block, and see the error right there. I had a ‘wrong number of arguments’ somewhere. But I can’t understand the `ert-deftest` error message.

## Another step back

Running the function in an org-mode code block worked. the function doesn’t. I needed my rubber duck. Thank you dear reader.

I don’t know why emacs’ `ert-deftest` test framework needs so many keystrokes. I need to evaluate the buffer (the place where you edit files) and then run the test runner separately. Org-mode worked but also this is not where the code should end up.

The example code in the blogpost used `message`, so I added that to my emacs lisp file. Now I can evaluate the buffer with a changed function, and see the output (in the ‘messages’ buffer, and in the status line below)

Hand drawn state diagram, transcribed below in ‘Inline session transcript’ as tables and part mermaid diagram.
what inline image location should be