js-test

Low budget expect-based unit tests. Isolates between invocations and safely contains everything that can go wrong.

Usage

1. Import and instantiate the UnitTest class.
2. Invoke method test, supply a description and callback with an expect parameter.
3. Invoke the supplied expect function, supply the test data.
4. Invoke the BDD testing methods of the returned object.

import UnitTest from "js-test";

const myTest = new UnitTest();

const testPromise = myTest.test("My Test", expect => {
	expect(2+2).toBe(4);
	expect(2+2).toNotBe(5);
});

testPromise.then(testStatus => {
	if(testStatus)
		console.log("Test passed!");
	else
		console.log("Test failed!");
});

Console output:

Test "My Test":
        ƒ Test started 2024-03-21T02:35:44.098Z
        ✓ Test PASSED in 0.081ms

Test passed!

UnitTest Class

new UnitTest();

The class UnitTest is used to execute tests, organize test settings, and store test logs.

Instance Methods

UnitTest.prototype.test Method

test( description: string, testFunction: (expect) => any ): Promise<boolean>

Calls the given testFunction function and supplies an expect function as the input parameter.

Returns a Promise which resolves to a boolean which indicates if the test passed or failed.

expect returns a new Expectation class instance. (See Expectation Class).

Here is an example of a valid testFunction:

function(expect) {
	expect(anyValue).toBe(anyValue);
}

Instance Properties

history Property

• Type string[][]

The history property contains logs of past tests. Is an Array which contains Arrays of strings.

emit Property

• Type boolean
• Default = true

The emit property is a boolean which ndicates if test progress and results should be logged to console.

Expectation Class

new Expectation(anyValue: any);

The test callback is supplied with an expect factory function which returns an Expectation instance.

Instance Properties

actualValue Property

• Type: any

The value given to expect, regarded as the "actual data" and not the expected data.

Instance Methods

Each of the following methods throws an ExpectError when its condition fails:

Method	Expect Input	Method Input	Condition Description
toBe	any	any	Passes based on the expected value being strictly equivalent to the given value.
toNotBe	any	any	Opposite of toBe. Passes based on the expected value being strictly equivalent to the given value.
toReturn	Function	any	Passes based on the expected function return value being strictly equivalent to the given value.
toNotReturn	Function	any	Opposite of toReturn. Passes based on the expected function not returning the given value, or none at all.
toThrow	Function	any	Passes based on the expected function throwing an instance of the given error, or at all.
toNotThrow	Function	any	Opposite of toThrow. Passes based on the expected function not throwing an instance of the given error, or none at all.