Time for another open-source adventure! We’ll be joined by Max Jacobson as we visit the Rust cli-tool Tokei. Tokei generates statistics around your code and language usage. For example, chael.codes looks like:

Forem, the repo behind therelicans.com and dev.to, looks like this:

We’re going to pick up an issue with a lot of discussion that hasn’t been touched in 10 months that I personally like. Those screenshots before weren’t very engaging, right? Let’s add some lovely color to Tokei’s terminal output!

There are some requirements listed out in the issue above.

• It must look good in light and dark mode terminals
• A crate should manage colorizing the output
• A color flag should manage color output --color (always|auto|never)
• thick rows === should be bold and the thin rows — dimmed

I think it’d look nice to give all the languages a cyan color, and emphasize the subtotals.

First step is identifying how we’ll cover color output, and the issue points us to colored which is based on a Ruby gem of the same name. Usage is very straightforward. println!("Hello, {}!", "world".green().bold()) will use the terminal’s colors, and bold the text.

Note that “cyan” or “green” may not always be cyan or green, they’re just roles in your terminal color scheme.

Next, it’s time to think about how and where to output these colors. Tokei implements a printer interface in cli_utils.rs which is where I found the headers!

With some lovely colors and style implemented in Tokei, it’s time to think about those command line args and turning off color. Some people (like other computers) prefer not to have color. I think we handle this in cli.rs. ShouldColorize respects environment variables like NOCOLOR and CLICOLOR, but flags seem helpful too. We should document this regardless.

This is the technical plan for a stream on 4/9. We’ll start with project setup, and testing out Tokei at 1500UTC, then we’ll be joined by Max Jacobson at 1800 UTC to complete the work of creating our changes and PR.