• Going mad trying to assert non nulls with typescript as Array.filter is not good enough.

• Reading about predicate, but still struggled a lot.

  • https://www.typescriptlang.org/docs/handbook/2/narrowing.html#using-type-predicates

  • https://www.benmvp.com/blog/filtering-undefined-elements-from-array-typescript/

  • This was the winning solution:

function isNonNull<T>(val: T | null | undefined): val is T {

	return val !== null && val !== undefined;

}

const cleanupNullsinArray = cleanupNulls.filter(isNonNull);

https://www.reddit.com/r/typescript/comments/hkndzx/comment/fwtttlg/?utm_source=share&utm_medium=web2x&context=3

• Have success with openapi-client-axios and [openapi-client-axios-typegen]](https://github.com/anttiviljami/openapi-client-axios/blob/master/packages/openapi-client-axios/README.md#generating-type-files-dts) for generating types automatically from any open-api compliant REST api.