Upgrading JavaScript to ES6 and using TypeScript as a shortcut
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This document discusses upgrading JavaScript to ES6 and using TypeScript as an alternative. It covers some of the old issues with JavaScript, the learning process, tooling challenges, and dependency on libraries/frameworks. ES6 promises to address many of these with new features, but browser support is still evolving so transpilation is needed. TypeScript is presented as a shortcut that provides type safety and class-based syntax without transpilation overhead. The document also mentions the ChakraCore JavaScript engine as a promising new development.
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Upgrading JavaScript to ES6 and using TypeScript as a shortcut
- 1. Upgrading JavaScript to ES6 and using TypeScript as a shortcut Chris Heilmann @codepo8, NDC, Oslo, June 2016
- 2. Of innovation and impatience Chris Heilmann @codepo8, Future Decoded, London, Nov 2015 CHRIS HEILMANN @CODEPO8
- 3. LET’S TALK JAVASCRIPT… • Old issues • The learning process • The tooling issue • The library/framework issue • ES6 and its promises • ES6 and its realities • Typescript • The ChakraCore thing
- 4. OLD ISSUES OF JAVASCRIPT
- 5. JAVASCRIPT CLIENT- SIDE HAS ISSUES… • It is not fault-tolerant • Many different parties mess with it • You don’t know the environment it runs in • It has always been part of the browser and dependent on its release and upgrade cycle
- 6. JAVASCRIPT THE LANGUAGE HAS ISSUES (OPPORTUNITIES)… • typeof NaN === number • No type safety • No classes • “it feels rushed”
- 9. THE JAVASCRIPT LEARNING PROCESS
- 10. THE JAVASCRIPT LEARNING PROCESS HAS ALWAYS BEEN INTERESTING… • Use view source to see what others are doing… • Copy and paste the bits that look like they are responsible for some things • Change some numbers around • Run into errors • Blame Internet Explorer
- 11. THIS, OF COURSE, WAS WRONG AND WE GOT MORE PROFESSIONAL… • Search for a solution on Stackoverflow • Copy and paste the bits that look like they are responsible for some things • Change some numbers around • Run into errors • Blame JavaScript for being terrible and not a real language • For good measure, blame Internet Explorer.
- 12. SHORTCUTS…
- 13. WITH ES6 WE HAVE A CLEAN NEW SLATE… (AND YOU CAN’T BLAME IE ANY MORE)
- 14. SEE THE BABEL.JS DOCS AND TRY IT IN THE BROWSER… https://babeljs.io/docs/learn-es2015/
- 16. READ THE EXCELLENT BOOK EXPLORING ES6 FOR FREE (OR BUY IT, AXEL DESERVES SUPPORT) http://exploringjs.com/es6/
- 19. AND IT DIFFERS FROM BROWSER TO BROWSER…
- 22. A simple way to detect how old a part of our massive site is checking which version of jQuery was used in that part of it. It’s like rings in a tree trunk. https://www.flickr.com/photos/91183364@N08/13916636762 “
- 27. FRAMEWORKS ARE GREAT… • They are fun to use - achieve a lot very quickly • You build complex apps in a matter of minutes • They work around pesky browser bugs • They are good on your CV
- 28. …BUT THEY ALSO COME WITH DEVELOPER COST • Learning new frameworks • Re-learning new frameworks • Debugging frameworks • Setting up developer environments • Cutting down on possible hires/ adding to onboarding time
- 29. AND WE SHOULD CONSIDER THE EFFECTS WE HAVE ON OUR END USERS… • Time to load / execute • Bandwidth used • CPU usage • Frame rate (60 fps) • Memory usage • Battery hunger
- 30. WE’RE GOING FULL SPEED ON INNOVATION… • Componentised Web • Extensible Web Manifesto • WebGL • WebAssembly/ASM.js • PostCSS • Progressive Apps
- 31. • We work around browser issues • We make web standards of tomorrow work today. • We build solutions to clean up others and make them smaller • And each of those comes with a “don’t use in production” label. BUILDING LIBRARIES AND FRAMEWORKS THAT MAGICALLY FIX THINGS HAS BECOME FASHIONABLE…
- 32. ES6 AND ITS PROMISES…
- 33. 1997 2015 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 1997 ECMAScript1 1998 ECMAScript2 1999 ECMAScript3 2005 - 2007 ECMAScript4 - Abandoned 2009 ECMAScript5 2015 ECMAScript6 JAVASCRIPT EVOLVES…
- 34. 1997 2015 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 1997 ECMAScript1 1998 ECMAScript2 1999 ECMAScript3 2005 - 2007 ECMAScript4 - Abandoned 2009 ECMAScript5 2015 ECMAScript6 …NOW WE HAVE ES6! • 5+ years since ES5 ratification • Significant changes in 15+ years • Backwards compatible • Ratified June 2015 http://www.ecma-international.org/publications/standards/Ecma-262.htm
- 35. • Arrow functions as a short-hand version of an anonymous function. • Block-level scope using let instead of var makes variables scoped to a block (if, for, while, etc.) • Classes to encapsulate and extend code. • Constants using the const keyword. • Default parameters for functions like foo(bar = 3, baz = 2) • Destructuring to assign values from arrays or objects into variables. • Generators that create iterators using function* and the yield keyword. • Map, a Dictionary type object that can be used to store key/value pairs. and Set as a collection object to store a list of data values. • Modules as a way of organizing and loading code. • Promises for async operations avoiding callback hell • Rest parameters instead of using arguments to access functions arguments. • Template Strings to build up string values including multi-line strings. ES6 COMES WITH SO MUCH GOODNESS, TECHNICALLY IT HAS TO BE FATTENING…
- 36. Library Builders map, set & weakmap __proto__ Proxies Symbols Sub7classable built7ins Scalable Apps let, const & block7 scoped bindings Classes Promises Iterators Generators Typed arrays Modules Syntactic Sugar Arrow functions Enhanced object literals Template strings Destructuring Rest, Spread, Default String, Math, Number, Object, RegExp APIs ALL OF THESE PARTS HAVE DIFFERENT AUDIENCES
- 37. SUPPORT IS ENCOURAGING (EDGE, FIREFOX, CHROME, SAFARI (ON 9)) http://kangax.github.io/compat-table/es6/
- 38. ES6 AND ITS REALITIES…
- 39. THE PROBLEM: FOR NON-SUPPORTING ENGINES, ES6 FEATURES ARE SYNTAX ERRORS…
- 40. THE SOLUTION: TRANSPILING INTO ES5… https://babeljs.io • Converts ES6 to older versions on the server or the client • In use by Facebook and many others • Used in editors and tool chains
- 41. TRANSPILED CODE…
- 42. THE VICIOUS INNOVATION CYCLE… https://github.com/samccone/The-cost-of-transpiling-es2015-in-2016 PICK YOUR TRANSPIRATION TOOLCHAIN…
- 43. ✘ Extra step between writing code and running it in the browser. ✘ We don’t run or debug the code we write. ✘ We hope the transpiler creates efficient code ✘ We create a lot of code ✘ Browsers that support ES6 will never get any. THE PROBLEMS WITH TRANSPILING:
- 44. TYPESCRIPT
- 46. THE NEXT ES* NOW, WITHOUT THE TOOLCHAIN OVERHEAD… • Works in the browser, creates JavaScript • Class based, type safe • Editor/tooling support • Used to write large frameworks and libraries (Dojo, Angular) • Used heavily in Microsoft
- 48. NEW BROWSER, NEW JS ENGINE
- 52. HTTPS:// .WTF
- 53. NODE USING CHAKRACORE https://blogs.windows.com/msedgedev/2016/01/19/nodejs-chakracore-mainline/
- 54. NODE USING CHAKRACORE https://blogs.windows.com/msedgedev/2016/01/19/nodejs-chakracore-mainline/
- 55. NODE USING CHAKRACORE https://blogs.windows.com/msedgedev/2016/01/19/nodejs-chakracore-mainline/
- 57. 🐝 JavaScript is now ES6 🐝 JavaScript moved beyond the browser 🐝 We have a tooling problem - now we have too many options 🐝 JavaScript needs to cater for a lot of different developer needs 🐝 Help the language by picking what makes you effective and doesn’t hurt your users. 🐝 Help improve the tools that are being built right now! IN SUMMARY…