How to (semi-)automate JavaScript refactoring

Disposable robot assassins and spreadsheets

Computers aren’t ready to write much of our code for us, but they can still help us clean and improve our code.

At Fluent 2013, O’Reilly’s Web Platform, JavaScript and HTML5 conference, Giles Bowkett demonstrated a wide variety of ways to write code that helps refactor code, showing developers a variety of ways to clean up and simplify their JavaScript. He gave ‘disposable robot assassin at large’ as his title, but it fit better with the code he was demonstrating.

Bowkett explored many options and iterations of his automation ideas,

  • The roots: Martin Fowler’s classic Refactoring. [at 00:50]
  • “Probably the first time ever you see a developer or hacker enthusiastic about using a spreadsheet… I am that fluke.” [at 01:48]
  • Matching method names with the ack and wc Unix command line utilities, and finding some useless methods. [at 5:58]
  • “More complex information… surfacing an implicit object model.” [at 7:45]
  • Filter scripts and text streams [at 14:45]
  • “Towlie, because it liked to make things DRY”, using similarity detection in Ruby. [at 16:37]
  • Building on JSLint [at 20:10]
  • Switching to a Ruby parser for JavaScript to calculate differences [at 21:49]
  • JavaScript parsers: Esprima [at 27:26]
  • “Have script that… tells you this file is the one that people have edited most frequently. [at 30:29]
  • Grepping through git history [at 32:53]
  • “Automatic refactoring will let you get to better code much faster.” [at 36:25]

It’s an amazing mix of capabilities that let you build your own robot (code) assassins.

If the Web Platform, JavaScript, and HTML5 interest you, consider checking out our growing collection of top-rated talks from Fluent 2013.

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