Hoist and fold variable declarations within scopes, so that each variable has only one declaration per scope. Don’t touch functions. Useful to normalize code before analysis, like data-flow etc.
npm install ast-redeclarevar parse = require('esprima').parse;
var generate = require('escodegen').generate;
var redeclare = require('ast-redeclare');
var ast = parse(
'var a = 1, b = 2; if (a > 1) { var c = b; } else {var c = 3;} var d = 4;'
);
ast = redeclare(ast);
generate(ast);
//var a, b, c, d; a = 1; b = 2; if (a > 1) { c = b; } else { c = 3; }; d = 4;