turns the modified AST back into code. What is Babel JavaScript transpiler Initially, the main focus of babel is to convert ECMAScript 2015+ (ES6+) code into a backwards compatible version of JavaScript that can be run by older JavaScript engines Nowadays, Babel is used to convert (transpile) JSX syntax, Typescript, Code Compression, and any syntaxs in proposal stage.So there should be some checks done to skip the transformation. However, in real-world code where multiple visitor and plugins are used, there are chances that a node might get visited more than once (although rare, it happens). We're defining an object literal which implements a visitor property that consists of an object of methods named to match the node it should process (typing is based on In this example, we're looking for Identifier node, and the function will visit both Identifier once ( n and y).

provide us with a way to get to the node that we're interested in using a pattern known as visitor.provides a parse method that converts source code into an AST.In the following example, we’re looking to change the variable keyword n into x, the flow of the transformation is as follow: Putting the three steps together, we’re able to manipulate code with confidence by modifying the AST using Babel.

What is babel js