According to Jeff Miller's Earliest Known Uses of Some of the Words of Mathematics, the term kernel was first used in this meaning by Pontryagin (in translation by Lehmer) in the slightly broader context of group homomorphisms. It doesn't say why Pontryagin or Lehmer chose that particular word though.
matrices - Word origin / meaning of 'kernel' in linear algebra ...
78 A semicolon is used to separate variables from parameters. Quite often, the terms variables and parameters are used interchangeably, but with a semicolon the meaning is that we are defining a function of the parameters that returns a function of the variables.
Jest is a delightful JavaScript Testing Framework with a focus on simplicity. It works with projects using: Babel, TypeScript, Node, React, Angular, Vue and more!
If you want that, you can use ts-jest instead, or just run the TypeScript compiler tsc separately (or as part of your build process). Via ts-jest ts-jest is a TypeScript preprocessor with source map support for Jest that lets you use Jest to test projects written in TypeScript.
In your test files, Jest puts each of these methods and objects into the global environment. You don't have to require or import anything to use them. However, if you prefer explicit imports, you can do import {describe, expect, test} from '@jest/globals'.
Jest is fast, but due to Jest's test isolation, slow user code often exacerbates performance issues and leads to slow test runs. When tests leave behind open handles like unclosed timers or connections to other services, it can cause Jest to hang or slow down. Jest 30 has gotten better at detecting and reporting these issues, which helps you identify and fix slow or problematic tests more ...