Testing Basic Concepts by Iván Corrales Solera, @wesovi

Index

● Code with tests vs code w/o tests● Tests oriented development● Types of testing● Frameworks and tools (Java apps)● Tests automation and CI● Testing examples

Code with tests or w/o tests

● Do you think is better to do tests in your developments?○ I supposed your answer would be YES

● Do you think development process take longer if we do tests?○ YES? Why?○ No, You are right, but why?

● What are the benefits of doing testing?○ ….

Brief questions

Code with or w/o testsCode with TestsCode w/o Tests

Refactor is so risky!

Just necessary code

Software with unused

code

Tests are our best documentationWe need to

get in the codeDevelopers Spending time

on understanding what code does

Life is easier for new developers

Quick bug-fixing

Quality Software

Spending long time on

bug-fixing

compiled code but

NOT software..

Re-factor is safe

Tests oriented development

Start writing tests

See the tests fail

Write code to make the tests pass

Pass the tests

TDD

● We will write code to make tests work instead of writing some tests to check part of our code.

● High test coberture levels.

● If we need to do bug-fixing we will start writing some tests before making changes in the code.

● Developers with experience in that programming language.

BDD

● No technical people can define our tests or help us to write them at least.

● Both technical and non technical people speak the same language.

● BDD doesn’t mean not to do unit testing.

● Our user stories will be completed when acceptance criterias are satisfied.

● User stories can be tracked in the code.

Comparison

Steps1. We have the software requirements2. We think about what we need to test3. We write some tests4. Tests will fail5. We write code to pass the tests6. We can do some re-factor

Pros● Code with quality● We do not have unnecessary code● We ensure our software works as expected.● High test coberture level● Low Bug-fixing time

Steps1. We have the software requirements2. We write code for the requirements3. We write some tests to check our software

work 4. Run the tests5. We’ll be happy when we have a test that

pass (probably because we know the result before writing it)

Pros● We have code with some tests● Some coberture level● Highly probably software with no high

quality

Writing code before tests Test before coding

Types of testing

Unit Testing

Integration Testing

Acceptance Testing

Stress Testing

UI Testing

Monkey Testing

Load Testing ….. Testing, Testing, Testing

Plenty types of testing… BUT we only need to do those testings that contribute to ensure the quality of our application

Tests oriented development

People not used to do test

Just code but NOT Software

Maybe Over tested applications...

Software with QA and correct tests

No tests

We do not apply the correct testing

Identify which testing are suitable for our application

Code with lack of Testing

Tips on Testing

Do tests but just those ones that have sense for your code

Identify what kind of testing should we do depending on the application

Practicing TDD or NOT is up to the developers. They should never be forced to do it

Enforce developers to do tests but do NOT establish a minimum test coberture

Unit Testing

What are the unit testing for?

● Ensure a piece of code or method works as expected● Make us achieve high test coberture levels● Easy for developers but not understable by non-technical people.● Tests must be run without application deployments● Mocks are required

When do not we have to do unit testing?

● Front end applications● We use MDA● We use kind of code generation

frameworks.

When should we do unit testing?

● Complexed methods● Algorithms and mathematics calculus

Integration Testing

When do not we have to do integration testing?

● Our application does only one basic thing such as a math operation or display hello world in the screen.

When should we do integration testing?

● Most of architectures: WS, Batch, microservices ,...

● Backend developed in Javascript (e2e)● User interfaces

What are the integration testing for?

● Ensure our system works as expected.● Does not really guarantee a high test coberture level.● They must be run in environment similar to the production one.● We could be forced to use mocks in case of we interact with third-party systems.

Acceptance Testing

What are the acceptance testing for?● Make technical and non technical people speak the same language● In scrum these tests would be the acceptance criterias defined for the user stories.● If these are not defined by the Product Owner, we need his/her validation at least.Some people

think these tests are unnecessary since integration testing could be enough. (And they could be right indeed)

● Natural language syntax (When, Then, And…. ) See below an example:

Given 10 can of beersWhen I drink 2 of themThen I should have 8 in my fridge.

Frameworks and tools (Java apps)

Tests automation and CI

Compile & Build Unit Tests Integration Tests Acceptance Tests

● The above flow represents the steps in the ci process.

● Each step above would be a different job in Jenkins (or whichever other CI tool)

● Each step will generate a report with the results

● We should not move to the next step in the flow in case of there were tests failing

● Developers must be able to run the tests from their local environment.

Sample - e2e for nodejs REST APICode: https://github.com/wesovi/nodejs-authentication-apiTechnologies: Nodejs, mocha, supertestSnippet:

it('should response BAD REQUEST & the error details when password is empty ', function (done) { var credentials = {username:"email@mail.com"}; request(app) .post('/accounts/authenticate') .send(credentials) .set('Content-Type', 'application/json') .expect('Content-Type', 'application/json; charset=utf-8') .expect(400) .expect({errors:[{ param: 'password', msg: 'required' }]}) .end(done);});