packages/expect-more-jasmine/src/to-be-nil.ts
/// <reference types="jasmine" />
import { isNil } from 'expect-more';
import { printReceived } from 'jest-matcher-utils';
declare global {
namespace jasmine {
// eslint-disable-next-line @typescript-eslint/no-unused-vars
interface Matchers<T> {
/**
* Asserts that a value is `null` or `undefined`
* @example
* expect(undefined).toBeNil();
*/
toBeNil(): boolean;
}
}
}
export const toBeNilMatcher: jasmine.CustomMatcherFactory = () => {
return {
compare(value: unknown) {
const pass = isNil(value);
const message = pass
? `expected ${printReceived(value)} not to be null or undefined`
: `expected ${printReceived(value)} to be null or undefined`;
return { message, pass };
},
};
};
beforeAll(() => {
jasmine.addMatchers({
toBeNil: toBeNilMatcher,
});
});