Change Testing Framework

[aidanm3341]

This project currently uses Karma as its test runner. Since Karma is now deprecated and is no longer receiving any updates, we should update to use something more modern.

Technology Options

@bogdumi and I discussed this and came up with the following options:

• Jest - Popular, but does not always play nicely with ESM or Typescript
• Vitest - Newer, but focuses on ESM and Typescript, as well as being quick and robust.
• Node Test Runner - Doesn't support Typescript natively, and is a very barebones framework. Perhaps does not have the features necessary for a larger project.

Given our positive experience with Vitest and the maturity of its features, we are leaning towards that as the framework of choice to replace Karma.

[Davidhanson90]

My experiences migrating our projects to Jest have left me disappointed. It's not terrible but not brilliant either. Debugging harder generally and module support patchy.

Vite test is interesting but not tried yet. Would be interested to trial it.