OptionalmessageOrOptions: string | { expect.any() matches any object instance created from the constructor or a corresponding primitive type. Use it
inside
expect(value).toEqual(expected)
to perform pattern matching.
Usage
// Match instance of a class.
class Example {}
expect(new Example()).toEqual(expect.any(Example));
// Match any number.
expect({ prop: 1 }).toEqual({ prop: expect.any(Number) });
// Match any string.
expect('abc').toEqual(expect.any(String));
expect.anything() matches everything except null and undefined. Use it inside
expect(value).toEqual(expected)
to perform pattern matching.
Usage
const value = { prop: 1 };
expect(value).toEqual({ prop: expect.anything() });
expect(value).not.toEqual({ otherProp: expect.anything() });
expect.arrayContaining() matches an array that contains all of the elements in the expected array, in any order.
Note that received array may be a superset of the expected array and contain some extra elements.
Use this method inside expect(value).toEqual(expected) to perform pattern matching.
Usage
expect([1, 2, 3]).toEqual(expect.arrayContaining([3, 1]));
expect([1, 2, 3]).not.toEqual(expect.arrayContaining([1, 4]));
Compares floating point numbers for approximate equality. Use this method inside expect(value).toEqual(expected) to perform pattern matching. When just comparing two numbers, prefer expect(value).toBeCloseTo(expected[, numDigits]).
Usage
expect({ prop: 0.1 + 0.2 }).not.toEqual({ prop: 0.3 });
expect({ prop: 0.1 + 0.2 }).toEqual({ prop: expect.closeTo(0.3, 5) });
Optionalprecision: numberexpect.objectContaining() matches an object that contains and matches all of the properties in the expected
object. Note that received object may be a superset of the expected object and contain some extra properties.
Use this method inside expect(value).toEqual(expected) to perform pattern matching. Object properties can be matchers to further relax the expectation. See examples.
Usage
// Assert some of the properties.
expect({ foo: 1, bar: 2 }).toEqual(expect.objectContaining({ foo: 1 }));
// Matchers can be used on the properties as well.
expect({ foo: 1, bar: 2 }).toEqual(expect.objectContaining({ bar: expect.any(Number) }));
// Complex matching of sub-properties.
expect({
list: [1, 2, 3],
obj: { prop: 'Hello world!', another: 'some other value' },
extra: 'extra',
}).toEqual(expect.objectContaining({
list: expect.arrayContaining([2, 3]),
obj: expect.objectContaining({ prop: expect.stringContaining('Hello') }),
}));
expect.stringContaining() matches a string that contains the expected substring. Use this method inside
expect(value).toEqual(expected)
to perform pattern matching.
Usage
expect('Hello world!').toEqual(expect.stringContaining('Hello'));
expect.stringMatching() matches a received string that in turn matches the expected pattern. Use this method
inside
expect(value).toEqual(expected)
to perform pattern matching.
Usage
expect('123ms').toEqual(expect.stringMatching(/\d+m?s/));
// Inside another matcher.
expect({
status: 'passed',
time: '123ms',
}).toEqual({
status: expect.stringMatching(/passed|failed/),
time: expect.stringMatching(/\d+m?s/),
});
Function to extend Playwright’s expect assertion capabilities. This adds a new method
toBeVisiblewhich checks if an element is visible on the screen.