free-variables

Get a list of free variables used in a JS program. A free variable is one which is used but not declared.

Installation

With your favorite package manager:

• packin: packin add free-variables
• component: component install jkroso/free-variables
• npm: npm install free-variables

then in your app:

var free = require('free-variables')

API

free(ast)

Takes any standard JS AST and returns and Array of String's

var parse = require('esprima').parse
free(parse('console.log')) // => ['console']
free(parse('console[log]')) // => ['console', 'log']
free(parse('function b(){a}')) // => ['a']
free(parse('var a = 1; a + b')) // => ['b']
free(parse('a; var a')) // => []