/**
   * @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.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]]);
                          }
                      });
                  }
              }
          };
  
      }
  };