playwright/tests/expect/customEqualityTestersRecurs...

247 lines
7.2 KiB
TypeScript

/**
* 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.
*
*/
import { test, expect } from './fixtures';
import { expect as expectUnderTest, mock } from '../../packages/playwright/bundles/expect/src/expectBundleImpl';
// Test test file demonstrates and tests the capability of recursive custom
// testers that call `equals` within their tester logic. These testers should
// receive the array of custom testers and be able to pass it into equals
const CONNECTION_PROP = '__connection';
type DbConnection = number;
let DbConnectionId = 0;
class Author {
public name: string;
public [CONNECTION_PROP]: DbConnection;
constructor(name: string) {
this.name = name;
this[CONNECTION_PROP] = DbConnectionId++;
}
}
class Book {
public name: string;
public authors: Array<Author>;
public [CONNECTION_PROP]: DbConnection;
constructor(name: string, authors: Array<Author>) {
this.name = name;
this.authors = authors;
this[CONNECTION_PROP] = DbConnectionId++;
}
}
const areAuthorsEqual = (a: unknown, b: unknown) => {
const isAAuthor = a instanceof Author;
const isBAuthor = b instanceof Author;
if (isAAuthor && isBAuthor)
return a.name === b.name;
else if (isAAuthor !== isBAuthor)
return false;
else
return undefined;
};
const areBooksEqual = function(
a: unknown,
b: unknown,
customTesters: [],
) {
const isABook = a instanceof Book;
const isBBook = b instanceof Book;
if (isABook && isBBook) {
return (
a.name === b.name && this.equals(a.authors, b.authors, customTesters)
);
} else if (isABook !== isBBook) {
return false;
} else {
return undefined;
}
};
function* toIterator<T>(array: Array<T>): Iterator<T> {
for (const obj of array)
yield obj;
}
expectUnderTest.extend({
toEqualBook(expected: Book, actual: Book) {
const result = this.equals(expected, actual, this.customTesters);
return {
message: () =>
`Expected Book object: ${expected.name}. Actual Book object: ${actual.name}`,
pass: result,
};
},
});
// Create books with the same name and authors for use in tests. Without the
// custom tester, these books would not be equal because their DbConnections
// would have different values. However, with our custom tester they are equal.
const book1 = new Book('Book 1', [
new Author('Author 1'),
new Author('Author 2'),
]);
const book1b = new Book('Book 1', [
new Author('Author 1'),
new Author('Author 2'),
]);
const bookArg1a = new Book('Book Arg 1', [
new Author('Author Arg 1'),
new Author('Author Arg 2'),
]);
const bookArg1b = new Book('Book Arg 1', [
new Author('Author Arg 1'),
new Author('Author Arg 2'),
]);
const bookArg2a = new Book('Book Arg 2', [
new Author('Author Arg 3'),
new Author('Author Arg 4'),
]);
const bookArg2b = new Book('Book Arg 2', [
new Author('Author Arg 3'),
new Author('Author Arg 4'),
]);
const bookReturn1a = new Book('Book Return 1', [
new Author('Author Return 1'),
new Author('Author Return 2'),
]);
const bookReturn1b = new Book('Book Return 1', [
new Author('Author Return 1'),
new Author('Author Return 2'),
]);
const testArgs = [bookArg1a, bookArg1b, [bookArg2a, bookArg2b]];
// Swap the order of args to assert custom tester works correctly and ignores
// DbConnection differences
const expectedArgs = [bookArg1b, bookArg1a, [bookArg2b, bookArg2a]];
expectUnderTest.addEqualityTesters([areAuthorsEqual, areBooksEqual]);
test.describe('with custom equality testers', () => {
test('exposes an equality function to custom testers', () => {
const runTestSymbol = Symbol('run this test');
expectUnderTest.addEqualityTesters([
function dummyTester() {
return undefined;
},
]);
expectUnderTest(() =>
expectUnderTest(runTestSymbol).toEqual(runTestSymbol),
).not.toThrow();
});
test('basic matchers customTesters do not apply to still do not pass different Book objects', () => {
expectUnderTest(book1).not.toBe(book1b);
expectUnderTest([book1]).not.toContain(book1b);
});
test('basic matchers pass different Book objects', () => {
expectUnderTest(book1).toEqual(book1);
expectUnderTest(book1).toEqual(book1b);
expectUnderTest([book1, book1b]).toEqual([book1b, book1]);
expectUnderTest(new Map([['key', book1]])).toEqual(new Map([['key', book1b]]));
expectUnderTest(new Set([book1])).toEqual(new Set([book1b]));
expectUnderTest(toIterator([book1, book1b])).toEqual(toIterator([book1b, book1]));
expectUnderTest([book1]).toContainEqual(book1b);
expectUnderTest({ a: book1 }).toHaveProperty('a', book1b);
expectUnderTest({ a: book1, b: undefined }).toStrictEqual({
a: book1b,
b: undefined,
});
expectUnderTest({ a: 1, b: { c: book1 } }).toMatchObject({
a: 1,
b: { c: book1b },
});
});
test('asymmetric matchers pass different Book objects', () => {
expectUnderTest([book1]).toEqual(expect.arrayContaining([book1b]));
expectUnderTest({ a: 1, b: { c: book1 } }).toEqual(
expect.objectContaining({ b: { c: book1b } }),
);
});
test('spy matchers pass different Book objects', () => {
const mockFn = mock.fn<(...args: Array<unknown>) => unknown>(
() => bookReturn1a,
);
mockFn(...testArgs);
expectUnderTest(mockFn).toHaveBeenCalledWith(...expectedArgs);
expectUnderTest(mockFn).toHaveBeenLastCalledWith(...expectedArgs);
expectUnderTest(mockFn).toHaveBeenNthCalledWith(1, ...expectedArgs);
expectUnderTest(mockFn).toHaveReturnedWith(bookReturn1b);
expectUnderTest(mockFn).toHaveLastReturnedWith(bookReturn1b);
expectUnderTest(mockFn).toHaveNthReturnedWith(1, bookReturn1b);
});
test('custom matchers pass different Book objects', () => {
(expectUnderTest as any)(book1).toEqualBook(book1b);
});
test('toBe recommends toStrictEqual even with different Book objects', () => {
expectUnderTest(() => expectUnderTest(book1).toBe(book1b)).toThrow('toStrictEqual');
});
test('toBe recommends toEqual even with different Book objects', () => {
expectUnderTest(() => expectUnderTest({ a: undefined, b: book1 }).toBe({ b: book1b })).toThrow(
'toEqual',
);
});
test('toContains recommends toContainEquals even with different Book objects', () => {
expectUnderTest(() => expectUnderTest([book1]).toContain(book1b)).toThrow('toContainEqual');
});
test('toMatchObject error shows Book objects as equal', () => {
expect(() =>
expectUnderTest({ a: 1, b: book1 }).toMatchObject({ a: 2, b: book1b })
).toThrowErrorMatchingSnapshot(`<d>expect(</><r>received</><d>).</>toMatchObject<d>(</><g>expected</><d>)</>
<g>- Expected - 1</>
<r>+ Received + 1</>
<y>@@ -1,7 +1,7 @@</>
<d> Object {</>
<g>- "a": 2,</>
<r>+ "a": 1,</>
<d> "b": Book {</>
<d> "__connection": 5,</>
<d> "authors": Array [</>
<d> Author {</>
<d> "__connection": 3,</>`);
});
test('iterableEquality still properly detects cycles', () => {
const a = new Set();
a.add(book1);
a.add(a);
const b = new Set();
b.add(book1b);
b.add(b);
expectUnderTest(a).toEqual(b);
});
});