dgcoffman

const isUseEffect = (node) => node.callee.name === 'useEffect';

const argumentIsArrowFunction = (node) => node.arguments[0].type === 'ArrowFunctionExpression';

const effectBodyIsSingleFunction = (node) => {
  const { body } = node.arguments[0];

  // It's a single unwrapped function call:
  //   `useEffect(() => theNameOfAFunction(), []);`
  if (body.type === 'CallExpression') {

maiermic

Variance

The term variance describes how subtyping between higher kinded types is related to subtyping relations of their type arguments.

Higher Kinded Types

A higher kinded type composes type arguments to a new type. I use square bracket notation to define a higher kinded type:

C[T] // The higher kinded type `C` composes type argument `T` to a new type `C[T]`.

The same works with multiple type arguments: