odin-javascript-exercises/node_modules/eslint/lib/rules/no-undef-init.js

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2017-12-15 10:56:14 -08:00
/**
* @fileoverview Rule to flag when initializing to undefined
* @author Ilya Volodin
*/
"use strict";
const astUtils = require("../ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "disallow initializing variables to `undefined`",
category: "Variables",
recommended: false
},
schema: [],
fixable: "code"
},
create(context) {
const sourceCode = context.getSourceCode();
return {
VariableDeclarator(node) {
const name = sourceCode.getText(node.id),
init = node.init && node.init.name,
scope = context.getScope(),
undefinedVar = astUtils.getVariableByName(scope, "undefined"),
shadowed = undefinedVar && undefinedVar.defs.length > 0;
if (init === "undefined" && node.parent.kind !== "const" && !shadowed) {
context.report({
node,
message: "It's not necessary to initialize '{{name}}' to undefined.",
data: { name },
fix(fixer) {
if (node.parent.kind === "var") {
return null;
}
if (node.id.type === "ArrayPattern" || node.id.type === "ObjectPattern") {
// Don't fix destructuring assignment to `undefined`.
return null;
}
return fixer.removeRange([node.id.range[1], node.range[1]]);
}
});
}
}
};
}
};