jest/e2e/custom-matcher-stack-trace/__tests__/sync.test.js

57 lines
1.4 KiB
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
*/
'use strict';
function toCustomMatch(callback, expectation) {
const actual = callback();
if (actual === expectation) {
return {pass: true};
} else {
return {
message: () => `Expected "${expectation}" but got "${actual}"`,
pass: false,
};
}
}
expect.extend({
toCustomMatch,
});
describe('Custom matcher', () => {
it('passes', () => {
// This expectation should pass
expect(() => 'foo').toCustomMatch('foo');
});
it('fails', () => {
expect(() => {
// This expectation should fail,
// Which is why it's wrapped in a .toThrow() block.
expect(() => 'foo').toCustomMatch('bar');
}).toThrow('Expected "bar" but got "foo"');
});
it('preserves error stack', () => {
const foo = () => bar();
const bar = () => baz();
const baz = () => {
// eslint-disable-next-line unicorn/throw-new-error,unicorn/new-for-builtins
throw Error('qux');
};
// This expectation fails due to an error we throw (intentionally)
// The stack trace should point to the line that throws the error though,
// Not to the line that calls the matcher.
expect(() => {
foo();
}).toCustomMatch('test');
});
});