Ustream vs Legacy @matenadasdi

Ustream basics 80.000.000 visitors / month 5.000.000+ viewer hours on tough days

Legacy is not bad code, it’s just old or over-iterated

Everyone starts in the dark… but there is always light in the end of the tunnel

Our goal was to achieve more stability and scalability in our frontend codebase

Our situation was (like every frontend codebase some years ago) no tests no modules all-in-one feature based class system poor abstraction JSLint as “code quality tools”

It’s a new ERA it’s a heaven of tools and new solutions for frontend developers nowadays

we had 5 stages in our long journey it may help or inspire you too

Structure

separate business logic from its representation easy isolation dependency injection we had to create / use a new structure There are some must-have things for testing…

not the framework, the way of thinking matters

always think in layers with separated responsibilities

Sync Socket (full-duplex) Async get data set data DOM AJAX WebStorage Cookies Socket Ustream Flash API Longpoll Embeds Views manipulates events Controllers control notify Logics Models get data set data

our new small framework is under 10kb but we had millions of lines written in an old style

don’t be afraid to start the hardcore continuous integration

Testing

Mocha + Chai framework: Node and Browser support Separated assert libraries Tons of reporters mocking: SinonJS Spies, Stubs, Mocks Assertions for invocations wide framework support Faking AJAX, server module dependency mocking: SquireJS Dependency injector for RequireJS mock / store Unit testing

Unit testing is a must in every architecture but it’s not enough for client side code!

Testing real browser functionality with mocking and simulating the DOM can be a pain in the …

Node.js based navigation scripting PhantomJS / SlimerJS support screenshot capture you can skip or use your own testing framework Solution: CasperJS

Right now we have: parallel execution thanks to an own grunt task solution Tools based on Casper: Screenshot comparisan tool, regression testing (PhantomCSS) own testing wrapper layer with different presets and transparent modules. User.login(), etc. It’s really flexible and easy to customize!

Automation

Manual processes simply won’t work… but there is an easy cure!

GRUNT || GULP we use Grunt! Why not gulp? Bad question, both are awesome, move on, and pick one!:)

we could migrate our old PHP / Ruby / etc. based frontend jobs to Node there is a transparent layer for every frontend related task thanks to our dynamic GruntFile.js solution, adding new tasks is fast Thanks to Grunt

CI integration is important! with an automation layer, it’s easy to do

Rules & standards insurance for the future

Follow your rules, because if you break them, they are not rules anymore…

Code style!

JSHint ! ! pros: .jshintrc huge community wide IDE / Text editor integration grunt / gulp plugins ! cons: still regexp based (JSLint fork) not pluginable nearly impossible to write semantic rules

ESLint ! pros: pluginable tons of new rules rapidly growing community semantics ESPRIMA growing IDE / Text editor integration ! cons: you can tell maybe!

We’ve created our own rules

Complexity? Lines of code (LOC) Halstead indexes Maintainability index Cyclomatic complexity linearly independent paths in the method

JSComplexity & Plato We run complexity report in Jenkins nightly build for our whole JS codebase https://www.npmjs.org/package/complexity-report Plato is a great tool for manual examinations https://github.com/es-analysis/plato

Use your CI or Git hooks to force your rules & standards

Modules, modules!

async module loading dependency injection project based SOA workflow, we have to avoid code duplication in several repos/projects Why we’ve started our modularisation marathon

Do not worry! Code modifications can be automated! http://esprima.org/ { "type": "Program", "body": [ { "type": "VariableDeclaration", "declarations": [ { "type": "VariableDeclarator", "id": { "type": "Identifier", "name": "city" }, "init": { "type": "Literal", "value": "istanbul", "raw": "'istanbul'" } } ], "kind": "var" }, { "type": "IfStatement", "test": { "type": "BinaryExpression", "operator": "===", "left": { "type": "Identifier", "name": "city" }, "right": { "type": "Literal", "value": "istanbul", "raw": "'istanbul'" } }, "consequent": { var city = ‘istanbul’; ! if (city === ‘istanbul’) { conf = 'jsist'; }

NPM modules? Maybe private ones? more!

private repo server: Sinopia internal GitLab repos for each package grunt release task for NPM module release NPM in private https://github.com/geddski/grunt-release https://github.com/boennemann/grunt-semantic-release

Why? we can manage our dependencies in different projects / services separated tests & documentation for each module we also use NPM for non-node package management Yeoman for automated project configuration

That’s not dark anymore!:) This is where we are right now!

What we’ve achieved so far 600+ modules created hundreds of unit tests and Casper tests, and growing rapidly new and important core features are moved to the new structure we started to create our private NPM modules like hell! ready for Async module loading

Remember: It’s never too late! @matenadasdi