21 lines
438 B
JavaScript

import { types as t } from "@babel/core";
export default function() {
return {
visitor: {
Program(path) {
const { node } = path;
for (const directive of (node.directives: Array<Object>)) {
if (directive.value.value === "use strict") return;
}
path.unshiftContainer(
"directives",
t.directive(t.directiveLiteral("use strict")),
);
},
},
};
}