ast-node-builder

Checkout the api in this Playground

Read the introductory blog post to know more about the tool.

Build your Abstract Syntax Trees (AST) directly from code. You give the input in the form of code and get the builder API in jscodeshift.

Usage

const { buildAST } = require('ast-node-builder');
const { parse }  = require('recast');
const code = `
class MyComponent extends ReactComponent {
  constructor(a, b) {
    this.a = a;
    this.b = b;
  }

  hello(x, y) {
    console.log(x, y);
  }
}
`;

let ast = parse(code);

let pseudoAst =  buildAST(ast);
console.log(pseudoAst);

Output

j.classDeclaration(
  j.identifier('MyComponent'),
  j.classBody([j.methodDefinition(
    'constructor',
    j.identifier('constructor'),
    j.functionExpression(
      null,
      [j.identifier('a'),j.identifier('b')],
      j.blockStatement([j.expressionStatement(j.assignmentExpression(
        '=',
        j.memberExpression(
          j.thisExpression(),
          j.identifier('a'),
          false
        ),
        j.identifier('a')
      )),j.expressionStatement(j.assignmentExpression(
        '=',
        j.memberExpression(
          j.thisExpression(),
          j.identifier('b'),
          false
        ),
        j.identifier('b')
      ))])
    ),
    false
  ),j.methodDefinition(
    'method',
    j.identifier('hello'),
    j.functionExpression(
      null,
      [j.identifier('x'),j.identifier('y')],
      j.blockStatement([j.expressionStatement(j.callExpression(
        j.memberExpression(
          j.identifier('console'),
          j.identifier('log'),
          false
        ),
        [j.identifier('x'),j.identifier('y')]
      ))])
    ),
    false
  )]),
  j.identifier('ReactComponent')
)

Debugging

Place debugger statements in the code in appropriate places and run:

$ npm run debug

This will start mocha tests in debug mode and you can use Chrome Dev Tools to view the debugger.