Unit Testing

To view lecture notes for this course, please consult the github-pages.

Rediscovery of TDD

Instructions for Unit Exercises: 1. Go to unit folder cd unit 2. Open program.test.js and go to each TODO block. 3. Complete each todo block by adding unit tests. 4. Please run the following script to npm run unit:test in order to do the unit test exercises

1. Unit Test the Map Function:

nest.test('Unit test the map function', assert => {
    assert.equal(actual, expected,
        `should render default message`);
    assert.end();
});

For a typical unit test I usually create 2 variables one named actual and another named expect

For assert.equal(actual, expected, 'My message here') if actual and expected are equal then the unit test will pass.

The map function behaves in the following manner

[1,2,3,4,5].map(function(number) {
    return {
        value: number
    };
});

This will return the following structure

[
    { value: 1 },
    { value: 2 },
    ...
]

Add variables actual and expected to this first unit test. The equal method expects to get single property/value in order to pass 1 === 1 or "Mike" === "Mike" The deepEqual method does a deep property check like this [1,2,3] === [1,2,3]

2. Unit Test the Filter Function.

The filter function behaves in the following manner

[1,2,3,4,5].filter(function(number) {
    return number > 3;
});

This will return the following structure [4, 5]

Either choose assert.equal or assert.deepEqual but remember deepEqual does a deep check with arrays but equal checks properties.

3. Unit Test the concatAll Function.

The concatAll function behaves in the following manner

[
    [1,2,3,4,5],
    [6,7,8,9,10]
].concatAll();

This will return the following structure [1,2,3,4,5,6,7,8,9,10]

Write a Unit Test using the same format as previous 2 exercises.

nest.test('I am some text', assert => {
    const actual = ...;
    const expected = ...;
    assert.equal(
        actual,
        expected,
        'I should another text'
    );
    assert.end();
});

4. Unit Test the concatMap Function.

The concatMap function behaves in the following manner

const numStrings = [ ["One", "Two", "Three"], ["Four", "Five", "Six"] ];
[1, 2, 3, 4, 5].concatMap(function(num) {
    return numStrings[num];
});

This will return the following structure ["One", "Two", "Three", "Four", "Five", "Six"]