Testing your library with Jasmine

In Jasmine, tests are organized into test suites. Each test suite is defined with a call to the describe function that accepts two arguments, a string containing a description of the suite, and an arrow function whose body contains all tests of the suite.

In turn, each test is defined by calling the it function that accepts two arguments, a string containing a description of the test, and an arrow function whose body contains the code that defines the test. Thus, each test suite looks like the following:

describe("this is a test suite", () =>{
    it("this is test 1", () =>{
        //test code
        ...
        //test assertion
        expect(<an expression here).toBe(5);
    });
    ...
    it("this is test n", () =>{
        ....
    });
});

Each test contains at least one call to expect that compares an actual...