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