README.md

@testingrequired/expect

Usage

Example

import { expect, not, toEqual } from "@testingrequired/expect";

expect(10, toEqual(10));
expect("foo", not(toEqual("bar")));

Assertions

not

Invert assertion function:

import { expect, not, toEqual } from "@testingrequired/expect";

expect(10, not(toEqual(100)));

toBe

Assert referential equality:

import { expect, toBe } from "@testingrequired/expect";

const value = { foo: "bar" };

expect(value, toBe(value)); // True
expect(value, toBe({ foo: "bar" })); // False

toBeUndefined

Assert referential equality to undefined:

import { expect, toBeUndefined } from "@testingrequired/expect";

expect(undefined, toBeUndefined); // True
expect([1, 2, 3], toBeUndefined); // False

toBeNull

Assert referential equality to null:

import { expect, toBeNull } from "@testingrequired/expect";

expect(null, toBeNull); // True
expect([1, 2, 3], toBeNull); // False

toBeTrue

Assert referential equality to true:

import { expect, toBeTrue } from "@testingrequired/expect";

expect(true, toBeTrue); // True
expect(1, toBeTrue); // False
expect([1, 2, 3], toBeTrue); // False

toBeTruthy

Assert truthy value:

import { expect, toBeTruthy } from "@testingrequired/expect";

expect(true, toBeTruthy); // True
expect([1, 2, 3], toBeTruthy); // True
expect(0, toBeTruthy); // False

toBeFalse

Assert referential equality to false:

import { expect, toBeFalse } from "@testingrequired/expect";

expect(false, toBeFalse); // True
expect(0, toBeFalse); // False
expect([1, 2, 3], toBeFalse); // False

toBeFalsy

Assert truthy value:

import { expect, toBeFalsy } from "@testingrequired/expect";

expect(false, toBeFalsy); // True
expect(0, toBeFalsy); // True
expect(1, toBeFalsy); // False

toBeInstanceOf

Assert equality to instanceof:

import { expect, toBeInstanceOf } from "@testingrequired/expect";

class CustomError extends Error {}

const error = new CustomError();

expect(error, toBeInstanceOf(CustomError)); // True
expect(error, toBeInstanceOf(Error)); // True
expect(error, toBeInstanceOf(String)); // False

toEqual

Assert value equality:

import { expect, toEqual } from "@testingrequired/expect";

expect(10, toEqual(10)); // True
expect({ foo: "bar" }, toEqual({ foo: "bar" })); // True

toThrow

Assert function throws error:

import { expect, toThrow } from "@testingrequired/expect";

class CustomError extends Error {}

const expectedErrorMessage = "expectedErrorMessage";

const fn = () => {
  throw new CustomError(expectedErrorMessage);
};

expect(fn, toThrow()); // True
expect(fn, toThrow(expectedErrorMessage)); // True
expect(fn, toThrow(new CustomError(expectedErrorMessage))); // True