@sz-sw-le1/expect NPM

expect

Small assertion module.

Function	Description
expect(`a`).toBe(`b`)	Asserts that `a` and `b` are the same (`===`).
expect(`a`).toBeInstanceOf(`b`)	Asserts that `a` is an instance of `b`
expect(`a`).toEqual(`b`)	If `b` is a primitive then:`a === b`If `b` is not a primitive:• Asserts same prototype• Asserts same properties• Asserts property value recursively with `toEqual`
expect(`a`).toHaveProperty(`b`)	Asserts that object `a` has an enumerable/non-enumerable property called `b`.
expect(`a`).toHaveSubString(`b`)	Asserts that string `a` contains the sub-string `b`.
expect(`fn`).toThrowError()	Asserts that `fn` throws an error.
expect(`fn`).toThrowError(`message`)	Asserts that `fn` throws an error with a message containing `message`.

All assertions (except toThrowError) can be negated with .not:

expect(1).not.toBe(2)

Example usage:

const {createExpectationsContext} = require("expect")
const {expect, end} = createExpectationsContext()

expect(1).toBe(1)
end()

3 years ago