Writing my first automation testing

So let's continue our last discussion regarding automation testing and today I’ll show you examples of automation testing. Let’s begging by covering what you need to start testing. Remember we are going to test in Javascript code.

TESTING SETUP:

Test Runner:

We will need a test runner to execute your tests and summarize your test results. Example: Mocha

Assertion library:

Here we define our testing logic and conditions. This is where we define expectations. Example: Chai

For this example, I’m going to use JEST and this will be my test runner and my assertion library in one place. Today we are going over only unit testing.

If you wish to learn more about JEST JS here is the link for the docs: https://jestjs.io/

Installing JEST:

yarn add --dev jest

or with NPM:

npm install --save-dev jest

Note: Jest documentation uses yarn commands, but npm will also work. You can compare yarn and npm commands in the yarn docs, here.

Let’s get started by writing a test for a hypothetical function that returns the name and age of a person giving the input. this function will take two arguments: name and age. First, let's create the generator.js file:

exports.generatetext = (name, age) =>{
// return output text
return `${name} (${age} years old)`
};

Then, create a file named generator.test.js. This will contain our actual test and JEST will automatically look for files with the .test.js on their name. First, we need to import the file we are going to test relative to the position of our .test.js file and this is our first line of code.

const { generatetext} = require('./generator');
test('should output a name and age', () =>{
const text = generatetext('Max', 29);
expect(text).toBe('Max (29 years old)')
});

in this example, we are expecting the result for this text to be “Max (29 years old)” if we receive anything other than that this test will fail.

Make sure to add the following section to your package.json:

{
"scripts": {
"test": "jest"
}
}

Finally, run yarn jestor npm run jest and Jest will print this message:

PASS  cypress/integration/util.spec.js
 PASS  src/util.test.js
Test Suites: 2 passed, 2 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        2.486 s, estimated 3 s
Ran all test suites.
Done in 5.69s.

Now our test is passing.