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Master the Art of the AST and Take Control of Your JS

ESTree-based AST (abstract syntax tree)​

source code represented as a tree data structure

  • Input step - parse, traverse
  • Output step - manipulate, generate

parse: convert code to AST (there are several open source parsers online, e.g. astexplorer, esprima)

traversing: example, visitor pattern (when you care about only the nodes you want to use) instead of going from top to bottom

manipulate: example, using Babel to get rid of "debugger;"

generate code: example, jscodeshift (FB's refactoring tool) to replace all var nodes with let

source: youtube link