Do you really want a layer above your JavaScript?
September 3, 2015 @Criteo Paris, France
Julien Lavigne du Cadet, Charles Niaulin, Erik Uzureau
Overview
- Why use TypeScript at Criteo?
- Some opinionated feedbacks
- Is TypeScript right for your team?
What we do
Our Front Ends
TypeScript Pilot Project
- Started in June 2014
- 6 developers at first / several years commitment
- 1 "front end" developer
- Angular + C# backend
Why?
- Large scale & greenfield
- Strongly typed
- Feels at home for C# developers
- ES6 features before general availability
Meet the trolls
Static typing
What result would you expect ?
NaN !
Typescript in practice:
Typescript is not the silver bullet to catch errors
Uncaught TypeError: Cannot read property 'toString' of null
Does it compile in TS ?
YES
Does it compile in TS ?
YES
Does it compile in TS ?
YES
Does it compile in TS ?
NO
Most data/code you will interact with are not typed (JSON, JS libs)
Documentation closer to your code
... quicker than ...
Increase in lines of code, files
JS
TS
Or is it ?
87 files in momentjs excluding tests & locale.
...Due to ES6 modules use
Setup
You have to manage definition files to use JS libs
Build time
Comfortable for c# / java developers
Refactoring sweetness
Uncomfortable for JS developers
Does not imply you don't have to know JS
What result do you expect ?
[NaN, NaN, NaN]
The working version
For fun
For fun
Lack of community support
And yet...
...For a project released in april 2014
TypeScript &
Your Team
Size of Project
# devs
Your Team's Experience
Lifetime of Project
Motivation
Alternatives
JavaScript
- "strict mode"
- js-hint, es-lint
Static Checkers
- Google's Closure Compiler (@JsDoc)
- Facebook Flow
ES6 / ES2015
- Babel
- Traceur
