Hi folks - I've just now stumbled upon this discussion. @lvlte, I do understand the frustration and am sorry if there's a bit confusion going on right now.

TBH there have been several different styles how algorithm implementation code is supposed to look and how it's supposed to be run (i.e. tested):

• Simple JS files containing the algorithm itself + "test driver" code that outputs the results to the cconsole. Those algorithms are tested by simply running the whole JS file in node (CommonJS style.)
• (削除) JS files with doctest comments (削除ここまで) (we just got rid of those)
• JS files that adhere to ESM + dedicated test files. Tests are run through Jest, which picks up the babel config.
• ... and a bit of a wild mix altogether ;)

We discussed this in #720 where we decided that, the code shall be more consistent. Going forward, it makes sense to push towards ESM only (eventually just add the "type": "module" property in the package.json and remove the need for babel altogether. But we're not there yet ;)

So please try to write new additions ESM-style, without console.log, with export function myAlgorithm etc. + tests written in Jest. While this may be inconsistent at this moment with previous contributions, we're pushing towards migrating all existing code into the targeted style.