1 | /*
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2 | Copyright (C) 2012-2014 Yusuke Suzuki <utatane.tea@gmail.com>
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3 | Copyright (C) 2013 Alex Seville <hi@alexanderseville.com>
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4 | Copyright (C) 2014 Thiago de Arruda <tpadilha84@gmail.com>
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5 |
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6 | Redistribution and use in source and binary forms, with or without
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7 | modification, are permitted provided that the following conditions are met:
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8 |
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9 | * Redistributions of source code must retain the above copyright
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10 | notice, this list of conditions and the following disclaimer.
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11 | * Redistributions in binary form must reproduce the above copyright
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12 | notice, this list of conditions and the following disclaimer in the
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13 | documentation and/or other materials provided with the distribution.
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14 |
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15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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18 | ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
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19 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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20 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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21 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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22 | ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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23 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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24 | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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25 | */
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26 |
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27 | /**
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28 | * Escope (<a href="http://github.com/estools/escope">escope</a>) is an <a
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29 | * href="http://www.ecma-international.org/publications/standards/Ecma-262.htm">ECMAScript</a>
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30 | * scope analyzer extracted from the <a
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31 | * href="http://github.com/estools/esmangle">esmangle project</a/>.
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32 | * <p>
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33 | * <em>escope</em> finds lexical scopes in a source program, i.e. areas of that
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34 | * program where different occurrences of the same identifier refer to the same
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35 | * variable. With each scope the contained variables are collected, and each
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36 | * identifier reference in code is linked to its corresponding variable (if
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37 | * possible).
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38 | * <p>
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39 | * <em>escope</em> works on a syntax tree of the parsed source code which has
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40 | * to adhere to the <a
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41 | * href="https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API">
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42 | * Mozilla Parser API</a>. E.g. <a href="https://github.com/eslint/espree">espree</a> is a parser
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43 | * that produces such syntax trees.
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44 | * <p>
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45 | * The main interface is the {@link analyze} function.
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46 | * @module escope
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47 | */
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48 | /* eslint no-underscore-dangle: ["error", { "allow": ["__currentScope"] }] */
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49 |
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50 | import assert from "assert";
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51 |
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52 | import ScopeManager from "./scope-manager.js";
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53 | import Referencer from "./referencer.js";
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54 | import Reference from "./reference.js";
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55 | import Variable from "./variable.js";
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56 |
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57 | import eslintScopeVersion from "./version.js";
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58 |
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59 | /**
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60 | * Set the default options
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61 | * @returns {Object} options
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62 | */
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63 | function defaultOptions() {
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64 | return {
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65 | optimistic: false,
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66 | directive: false,
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67 | nodejsScope: false,
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68 | impliedStrict: false,
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69 | sourceType: "script", // one of ['script', 'module', 'commonjs']
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70 | ecmaVersion: 5,
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71 | childVisitorKeys: null,
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72 | fallback: "iteration"
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73 | };
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74 | }
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75 |
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76 | /**
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77 | * Preform deep update on option object
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78 | * @param {Object} target Options
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79 | * @param {Object} override Updates
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80 | * @returns {Object} Updated options
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81 | */
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82 | function updateDeeply(target, override) {
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83 |
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84 | /**
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85 | * Is hash object
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86 | * @param {Object} value Test value
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87 | * @returns {boolean} Result
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88 | */
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89 | function isHashObject(value) {
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90 | return typeof value === "object" && value instanceof Object && !(value instanceof Array) && !(value instanceof RegExp);
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91 | }
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92 |
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93 | for (const key in override) {
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94 | if (Object.prototype.hasOwnProperty.call(override, key)) {
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95 | const val = override[key];
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96 |
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97 | if (isHashObject(val)) {
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98 | if (isHashObject(target[key])) {
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99 | updateDeeply(target[key], val);
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100 | } else {
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101 | target[key] = updateDeeply({}, val);
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102 | }
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103 | } else {
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104 | target[key] = val;
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105 | }
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106 | }
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107 | }
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108 | return target;
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109 | }
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110 |
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111 | /**
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112 | * Main interface function. Takes an Espree syntax tree and returns the
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113 | * analyzed scopes.
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114 | * @function analyze
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115 | * @param {espree.Tree} tree Abstract Syntax Tree
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116 | * @param {Object} providedOptions Options that tailor the scope analysis
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117 | * @param {boolean} [providedOptions.optimistic=false] the optimistic flag
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118 | * @param {boolean} [providedOptions.directive=false] the directive flag
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119 | * @param {boolean} [providedOptions.ignoreEval=false] whether to check 'eval()' calls
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120 | * @param {boolean} [providedOptions.nodejsScope=false] whether the whole
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121 | * script is executed under node.js environment. When enabled, escope adds
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122 | * a function scope immediately following the global scope.
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123 | * @param {boolean} [providedOptions.impliedStrict=false] implied strict mode
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124 | * (if ecmaVersion >= 5).
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125 | * @param {string} [providedOptions.sourceType='script'] the source type of the script. one of 'script', 'module', and 'commonjs'
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126 | * @param {number} [providedOptions.ecmaVersion=5] which ECMAScript version is considered
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127 | * @param {Object} [providedOptions.childVisitorKeys=null] Additional known visitor keys. See [esrecurse](https://github.com/estools/esrecurse)'s the `childVisitorKeys` option.
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128 | * @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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129 | * @returns {ScopeManager} ScopeManager
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130 | */
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131 | function analyze(tree, providedOptions) {
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132 | const options = updateDeeply(defaultOptions(), providedOptions);
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133 | const scopeManager = new ScopeManager(options);
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134 | const referencer = new Referencer(options, scopeManager);
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135 |
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136 | referencer.visit(tree);
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137 |
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138 | assert(scopeManager.__currentScope === null, "currentScope should be null.");
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139 |
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140 | return scopeManager;
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141 | }
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142 |
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143 | export {
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144 |
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145 | /** @name module:escope.version */
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146 | eslintScopeVersion as version,
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147 |
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148 | /** @name module:escope.Reference */
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149 | Reference,
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150 |
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151 | /** @name module:escope.Variable */
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152 | Variable,
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153 |
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154 | /** @name module:escope.ScopeManager */
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155 | ScopeManager,
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156 |
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157 | /** @name module:escope.Referencer */
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158 | Referencer,
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159 |
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160 | analyze
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161 | };
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162 |
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163 | /** @name module:escope.Definition */
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164 | export { Definition } from "./definition.js";
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165 |
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166 | /** @name module:escope.PatternVisitor */
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167 | export { default as PatternVisitor } from "./pattern-visitor.js";
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168 |
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169 | /** @name module:escope.Scope */
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170 | export { Scope } from "./scope.js";
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171 |
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172 | /* vim: set sw=4 ts=4 et tw=80 : */
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