/*
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Copyright (C) 2012-2014 Yusuke Suzuki <utatane.tea@gmail.com>
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Copyright (C) 2013 Alex Seville <hi@alexanderseville.com>
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Copyright (C) 2014 Thiago de Arruda <tpadilha84@gmail.com>
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* Escope (<a href="http://github.com/estools/escope">escope</a>) is an <a
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* href="http://www.ecma-international.org/publications/standards/Ecma-262.htm">ECMAScript</a>
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* scope analyzer extracted from the <a
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* href="http://github.com/estools/esmangle">esmangle project</a/>.
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* <p>
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* <em>escope</em> finds lexical scopes in a source program, i.e. areas of that
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* program where different occurrences of the same identifier refer to the same
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* variable. With each scope the contained variables are collected, and each
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* identifier reference in code is linked to its corresponding variable (if
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* possible).
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* <p>
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* <em>escope</em> works on a syntax tree of the parsed source code which has
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* to adhere to the <a
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* href="https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API">
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* Mozilla Parser API</a>. E.g. <a href="https://github.com/eslint/espree">espree</a> is a parser
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* that produces such syntax trees.
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* <p>
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* The main interface is the {@link analyze} function.
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* @module escope
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*/
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"use strict";
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/* eslint no-underscore-dangle: ["error", { "allow": ["__currentScope"] }] */
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const assert = require("assert");
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const ScopeManager = require("./scope-manager");
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const Referencer = require("./referencer");
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const Reference = require("./reference");
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const Variable = require("./variable");
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const Scope = require("./scope").Scope;
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const version = require("../package.json").version;
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/**
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* Set the default options
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* @returns {Object} options
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*/
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function defaultOptions() {
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return {
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optimistic: false,
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directive: false,
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nodejsScope: false,
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impliedStrict: false,
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sourceType: "script", // one of ['script', 'module']
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ecmaVersion: 5,
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childVisitorKeys: null,
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fallback: "iteration"
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};
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}
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/**
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* Preform deep update on option object
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* @param {Object} target - Options
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* @param {Object} override - Updates
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* @returns {Object} Updated options
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*/
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function updateDeeply(target, override) {
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/**
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* Is hash object
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* @param {Object} value - Test value
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* @returns {boolean} Result
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*/
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function isHashObject(value) {
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return typeof value === "object" && value instanceof Object && !(value instanceof Array) && !(value instanceof RegExp);
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}
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for (const key in override) {
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if (Object.prototype.hasOwnProperty.call(override, key)) {
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const val = override[key];
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if (isHashObject(val)) {
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if (isHashObject(target[key])) {
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updateDeeply(target[key], val);
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} else {
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target[key] = updateDeeply({}, val);
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}
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} else {
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target[key] = val;
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}
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}
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}
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return target;
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}
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/**
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* Main interface function. Takes an Espree syntax tree and returns the
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* analyzed scopes.
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* @function analyze
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* @param {espree.Tree} tree - Abstract Syntax Tree
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* @param {Object} providedOptions - Options that tailor the scope analysis
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* @param {boolean} [providedOptions.optimistic=false] - the optimistic flag
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* @param {boolean} [providedOptions.directive=false]- the directive flag
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* @param {boolean} [providedOptions.ignoreEval=false]- whether to check 'eval()' calls
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* @param {boolean} [providedOptions.nodejsScope=false]- whether the whole
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* script is executed under node.js environment. When enabled, escope adds
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* a function scope immediately following the global scope.
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* @param {boolean} [providedOptions.impliedStrict=false]- implied strict mode
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* (if ecmaVersion >= 5).
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* @param {string} [providedOptions.sourceType='script']- the source type of the script. one of 'script' and 'module'
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* @param {number} [providedOptions.ecmaVersion=5]- which ECMAScript version is considered
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* @param {Object} [providedOptions.childVisitorKeys=null] - Additional known visitor keys. See [esrecurse](https://github.com/estools/esrecurse)'s the `childVisitorKeys` option.
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* @param {string} [providedOptions.fallback='iteration'] - A kind of the fallback in order to encounter with unknown node. See [esrecurse](https://github.com/estools/esrecurse)'s the `fallback` option.
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* @returns {ScopeManager} ScopeManager
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*/
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function analyze(tree, providedOptions) {
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const options = updateDeeply(defaultOptions(), providedOptions);
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const scopeManager = new ScopeManager(options);
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const referencer = new Referencer(options, scopeManager);
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referencer.visit(tree);
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assert(scopeManager.__currentScope === null, "currentScope should be null.");
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return scopeManager;
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}
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module.exports = {
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/** @name module:escope.version */
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version,
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/** @name module:escope.Reference */
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Reference,
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/** @name module:escope.Variable */
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Variable,
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/** @name module:escope.Scope */
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Scope,
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/** @name module:escope.ScopeManager */
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ScopeManager,
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analyze
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};
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/* vim: set sw=4 ts=4 et tw=80 : */
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