Jörg Henning@JoergHenning

Software TestingExpress, Mocha, Chai

Why?

● Working software

● Intended functionality

● No bugs

● No downtimes

● No security issues

● Extensible, easy to extend & modify

(because we need to pivot)

Production Testing?

Your User

● “Negative Features”

● Bad reviews

● Users leave

● RIP Unicorn ♱

QA in the end

Feature A

Feature B

Feature C

QA + Bug Fixing

???

Agile Software Development

Technical Debt

Node.js release timeline

ES2015/ES6● arrows

● classes

● enhanced object literals

● template strings

● destructuring

● default + rest + spread

● let + const

● iterators + for..of

● generators

● unicode

● modules

● module loaders

● map + set + weakmap + weakset

● proxies

● symbols

● subclassable built-ins

● promises

● math + number + string + array + object APIs

● binary and octal literals

● reflect api

● tail calls

(see https://github.com/lukehoban/es6features)

Also check out http://node.green/!

Fear!

Test Automation

Manual Testing// test_multiply.js

var multiply = require('./multiply');

var theMeaning = multiply(6, 7);

console.log(theMeaning);

> node test_multiply.js

42

npm install -g mocha

Mochavar assert = require('assert');var multiply = require('./multiply');

describe('multiply', () => { it('should return 42 for 6 * 7', () => { var theMeaning = multiply(6, 7); assert.equal(theMeaning, 42); });});

npm install chai --save-dev

Chaivar expect = require(‘chai’).expect;var multiply = require('./multiply');

describe('multiply', () => { it('should return 42 for 6 * 7', () => { expect(multiply(6,7).to.equal(42)); });});

Chai - Styles● Assertion style:

○ require(‘chai’).assert => assert.equal(expected, actual);

○ Similar to built in assert, but more assertions

○ E.g.: assert.typeOf(), assert.lengthOf()

● BDD Style

○ require(‘chai’).expect => expect(actual).to.equal(expected);

○ require(‘chai’).should() => actual.should.equal(expected); // don’t do!

○ E.g.: expect(x).to.be.null; expect(obj).to.be.instanceOf(ctor); expect(foo).

to.not.equal(bar);

Full API: http://chaijs.com/api/

Source: https://www.simple-talk.com/sql/database-delivery/what-is-behaviour-driven-(database)-development/

Good tests are:● Fast - milliseconds!

● Small - test only a single piece of functionality at a time

● Simple - complexity = less reliability

● Plentiful - several tests per feature

● Isolated - have no dependencies between each other

● Readable - other people will need to read them too

● Clean - same code quality as the software they are testing

TDD/BDDThe two rules of TDD:

● Don’t write a single line of code unless you have a failing automated test● Eliminate duplication

How to?

● Write a small test (and watch it fail)● Make the test work (quick & dirty)● Eliminate duplication (refactor)

Behaviour Driven Development (also ATDD):

● Similar to TDD for higher level tests● Readable by Product Owners, Business Analysts, etc.

BDD

Feature: Listing command

In order to change the structure of the folder I am currently in

As a UNIX user

I need to be able see the currently available files and folders there

Scenario: Listing two files in a directory

Given I am in a directory "test"

And I have a file named "foo"

And I have a file named "bar"

When I run "ls"

Then I should get:

"""

bar

foo

"""

http://docs.behat.org/en/v3.0/ (PHP)

https://cucumber.io/ (Rails)

https://github.com/joerx/expensely

fork, clone

git reset --hard v0.6.2