As for the applied notation, it was built with the aim of simulating a real environment. Where we need to maintain the standardization of a legacy system.

Floats can create big problems, so it's in our docs to avoid them whenever possible, regardless of your rationale about a legacy system, which wasn't stated in the description. If you must simulate a legacy environment, I strongly suggest finding another angle to do it on that won't cause difficulties in translation and unpredictably failing assertions.

Staying away from floating-point values is usually a good way to solve problems related to ... monetary values (dollars and cents)

See:

• https://docs.codewars.com/authoring/recipes/floating-point/#why-are-floating-point-numbers-problematic
• Is floating-point math broken?

Thanks for the contribution. I used the template provided by codewars, I was surprised by the bug with assert, but I already applied the suggested fix.

As for the applied notation, it was built with the aim of simulating a real environment. Where we need to maintain the standardization of a legacy system.

Thanks for the contribution. I included random tests

There are no random tests. See https://docs.codewars.com/authoring/guidelines/submission-tests#random-tests

A few issues:

• The provided test says assert isn't defined. After importing it, diffs print poorly due to truncation. I suggest adding:

  const {assert, config} = require("chai");
  config.truncateThreshold = 0;
  

• Discounts stored as strings and prices stored as floats seem unusual. These practices coupled with the unstated rounding requirement push the solution to resort to awkward/artificial formatting. I'd store everything as an integer to avoid floating point misbehavior, especially if this is ever translated to non-JS languages.
• I can't do const newPrice = ... because newPrice is inexplicably defined in the preloaded. I'd suggest removing this.
• Rather than "new-price", I'd suggest a camel cased key: "newPrice", which is more idiomatic for JS, allowing natural dot notation access.