jest-fuzz

Fuzz testing for jest

Installing

use your favorite package manager

$ yarn add jest-fuzz $ npm install jest-fuzz

Using

Import the test suite in your test code.

const Fuzz = require('jest-fuzz');

...

Creating a test

First of all, you need to use the Fuzz.test instead of Jest's test and what's the difference? Basically Fuzz.test create a wrap to all random data that it will generate for your code.

Now, this is how a test has to will be described.

Fuzz.test("Name", Fuzzer, (data) => {
 //expectations
}

where,

• Name -> String representing the name of this suite
• Fuzzer -> A fuzzer function that you can see below
• Callback (data) -> This callback is where your tests will be, and the data param is a random data to your test.

Fuzzers

Fuzzers are the data representation of what you need to test.

for example, if you have a function that needs a string, you can use Fuzz.string() also, pass the parameters for this string.

these are the built-in fuzzers

Fuzzer	Options
Fuzz.string	{ length: Int (default=125), sufix: String (default=''), prefix: String (default='') }
Fuzz.int	{ Min: Int (default=-Infinity), max: Int (default=Infinity) }
Fuzz.float	{ Min: Int (default=-Infinity), max: Int (default=Infinity) }
Fuzz.bool
Fuzz.array	{ type: Fuzzer (default=Int), length: Int (default=300), minLength: Int (default=1) }

Creating a custom fuzzer

The custom fuzzer is a way to represent an object or other complex data.

To create you simply need to use the Fuzz.Fuzzer function

const exampleFuzzer = Fuzz.Fuzzer({
    method1: Fuzz.string(),
    method2: Fuzz.int()
});

Fuzz.test("My example", exampleFuzzer(), data => {
    // Test data.
}

Fuzz.it("My example", exampleFuzzer(), data => {
    // Test data.
}