Remove 'es6-promise' imports from legacy code. Using https://github.com/facebook/jscodeshift

transform.js

export default function transformer(file, api) {
	const j = api.jscodeshift;

	return j(file.source)
		.find(j.ImportDeclaration, {
			source: {
				value: 'es6-promise'
			}
		})
		.filter(({node}) => node.specifiers.filter(value => value.local.name === 'Promise').length > 0)
		.remove()
		.toSource();
}