packages/expect-more-jasmine/src/to-be-async-function.ts
/// <reference types="jasmine" />
import { isAsyncFunction } 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 a function using `async` and `await` syntax.
* @example
* expect(async () => { await fetch('...') }).toBeAsyncFunction();
*/
toBeAsyncFunction(): boolean;
}
}
}
export const toBeAsyncFunctionMatcher: jasmine.CustomMatcherFactory = () => {
return {
compare(value: unknown) {
const pass = isAsyncFunction(value);
const message = pass
? `expected ${printReceived(value)} not to be a function using async/await syntax`
: `expected ${printReceived(value)} to be a \`Function\` using async/await syntax`;
return { message, pass };
},
};
};
beforeAll(() => {
jasmine.addMatchers({
toBeAsyncFunction: toBeAsyncFunctionMatcher,
});
});