codemod

gistfile1.js

module.exports = function transformer(file, api) {
  const j = api.jscodeshift;
  
  const update = path => {    
    if (path.node.expression) {
      const body = j.blockStatement([j.expressionStatement(path.node.body)]);
      return j.functionExpression(path.node.id, path.node.params, body, true, false)
    }
    return j.functionExpression(path.node.id, path.node.params, path.node.body, true, false)
  };
  

  const isLab = node => {
    return node.declarations[0].id.name === 'lab';
  }
  
  
  const toYield = path => {
    return j.yieldExpression(path.node.argument);
  }

  const root = j(file.source);

  root.find(j.Identifier, { name: 'promiseLab' })
      .replaceWith(j.identifier('coLab'))

  //root.find(j.VariableDeclaration, isLab)
  //    .insertAfter("const Co = require('co');")

  root.find(j.ArrowFunctionExpression, { async: true })
      .replaceWith(update)

  root.find(j.AwaitExpression)
      .replaceWith(toYield)

  return root.toSource({quote: 'single'});
  
};