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A study of bugs

Notes published in Q3, 2021

Don't Edit Hosts File With Nano on a Mac

TLDR: If you are using a Mac, don't edit your hosts file with Nano and save it in Mac format. It will cause bizarre bugs in places you won't expect. If you are seeing bugs on a Mac with errors saying localhost is missing, try opening the hosts file and save it with Unix line ending.

I learned this while working on a React Native project, where Expo's development server just wouldn't start up. After a long and patient wait, an elaborate error message showed up. In which the most eye-catching line said:

RangeError [ERR_SOCKET_BAD_PORT]: options.port should be >= 0 and < 65536. Received 65536.

Comparing Arrays by Value in JavaScript

I didn't know I didn't know the answer when my friend showed me a simple piece of JavaScript code and asked me what would happen.

He said this caused a bug in a project he was working on and it took him hours to debug. Since I knew arrays in JavaScript are objects. And objects are only equal when they refer to the same thing in memory. If you do it as shown in ex. {2}, the result will certainly be true, because x and y indeed refer to the same thing.

In ex. {1}, a and b are defined differently. And I felt very clever when I correctly said the code on line 🕶 will produce a false. But — ⋯

Creating My Own Static Site Generator

Since I take a lot of notes, rcently I thought I could edit some of my notes and turn them into a blog. I wasn't satisfied with WordPress, because it's bloated. I didn't feel like to get familiar with the settings and configurations of other static site generators either. So I decided to write my own. I named it “Lysekil”, where I visited in late March and loved it there. I published it on GitHub and provided a brief documentation.

The color scheme used in the template was borrowed from the default “Red Graphite” theme of Bear, my favorite note-taking app. (It also happens to be Andy Matuschak's favorite note-taking app. I used to dither over a few other options, including Obsidian, RemNote and RoamResearch. In the end I would always come back to Bear.)

I used third-party Python packages to process markdown, generate the Atom feed and highlight code syntax. ⋯