hexo/node_modules/@babel/preset-modules/lib/plugins/transform-safari-block-shad.../index.js

47 lines
1.4 KiB
JavaScript

"use strict";
exports.__esModule = true;
exports.default = _default;
/**
* Fixes block-shadowed let/const bindings in Safari 10/11.
* https://kangax.github.io/compat-table/es6/#test-let_scope_shadow_resolution
*/
function _default({
types: t
}) {
return {
name: "transform-safari-block-shadowing",
visitor: {
VariableDeclarator(path) {
// the issue only affects let and const bindings:
const kind = path.parent.kind;
if (kind !== "let" && kind !== "const") return; // ignore non-block-scoped bindings:
const block = path.scope.block;
if (t.isFunction(block) || t.isProgram(block)) return;
const bindings = t.getOuterBindingIdentifiers(path.node.id);
for (const name of Object.keys(bindings)) {
let scope = path.scope; // ignore parent bindings (note: impossible due to let/const?)
if (!scope.hasOwnBinding(name)) continue; // check if shadowed within the nearest function/program boundary
while (scope = scope.parent) {
if (scope.hasOwnBinding(name)) {
path.scope.rename(name);
break;
}
if (t.isFunction(scope.block) || t.isProgram(scope.block)) {
break;
}
}
}
}
}
};
}
module.exports = exports.default;