1 | /*
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2 | * Copyright (C) 2016 salesforce.com, inc.
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3 | *
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4 | * Licensed under the Apache License, Version 2.0 (the "License");
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5 | * you may not use this file except in compliance with the License.
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6 | * You may obtain a copy of the License at
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7 | *
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8 | * http://www.apache.org/licenses/LICENSE-2.0
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9 | *
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10 | * Unless required by applicable law or agreed to in writing, software
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11 | * distributed under the License is distributed on an "AS IS" BASIS,
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12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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13 | * See the License for the specific language governing permissions and
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14 | * limitations under the License.
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15 | */
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16 |
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17 | /**
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18 | * Returns the property name of a MemberExpression.
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19 | * @param {ASTNode} memberExpressionNode The MemberExpression node.
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20 | * @returns {string|null} Returns the property name if available, null else.
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21 | */
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22 | function getPropertyName(memberExpressionNode) {
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23 | if (memberExpressionNode.computed) {
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24 | if (memberExpressionNode.property.type === "Literal") {
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25 | return memberExpressionNode.property.value;
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26 | }
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27 | } else {
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28 | return memberExpressionNode.property.name;
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29 | }
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30 | return null;
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31 | }
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32 |
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33 | /**
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34 | * Finds the escope reference in the given scope.
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35 | * @param {Object} scope The scope to search.
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36 | * @param {ASTNode} node The identifier node.
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37 | * @returns {Reference|null} Returns the found reference or null if none were found.
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38 | */
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39 | function findReference(scope, node) {
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40 | var references = scope.references.filter(function(reference) {
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41 | return reference.identifier.range[0] === node.range[0] &&
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42 | reference.identifier.range[1] === node.range[1];
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43 | });
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44 |
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45 | if (references.length === 1) {
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46 | return references[0];
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47 | }
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48 | return null;
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49 | }
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50 |
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51 | /**
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52 | * Checks if the given identifier node is shadowed in the given scope.
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53 | * @param {Object} scope The current scope.
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54 | * @param {Object} globalScope The global scope.
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55 | * @param {string} node The identifier node to check
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56 | * @returns {boolean} Whether or not the name is shadowed.
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57 | */
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58 | function isShadowed(scope, globalScope, node) {
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59 | var reference = findReference(scope, node);
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60 | return reference && reference.resolved && reference.resolved.defs.length > 0;
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61 | }
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62 |
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63 | /**
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64 | * Finds all the nodes used by a composed member expression.
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65 | * E.g.: Array.prototype.slice should produce
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66 | * [{type: "Identifier", name: "Array"}, {type: "Identifier", name: "prototype"}, {type: "Identifier", name: "slice"}]
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67 | * @param {ASTNode} node The MemberExpression node.
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68 | * @returns {Array} Returns a list of nodes that represent the namespace.
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69 | */
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70 | function buildMemberExpressionNamespace(currentScope, globalScope, node) {
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71 | var ns = [];
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72 | do {
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73 | ns.unshift(node.property);
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74 | if (node.object.type === "MemberExpression") {
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75 | node = node.object;
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76 | } else if (!isGlobalThisReferenceOrGlobalWindow(currentScope, globalScope, node.object)) {
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77 | ns.unshift(node.object);
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78 | node = undefined;
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79 | } else {
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80 | node = undefined;
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81 | }
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82 | } while (node);
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83 | return ns;
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84 | }
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85 |
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86 | /**
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87 | * Checks if the given identifier node is a ThisExpression in the global scope or the global window property.
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88 | * @param {Object} scope The current scope.
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89 | * @param {Object} globalScope The global scope.
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90 | * @param {string} node The identifier node to check
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91 | * @returns {boolean} Whether or not the node is a reference to the global object.
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92 | */
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93 | function isGlobalThisReferenceOrGlobalWindow(scope, globalScope, node) {
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94 | if (scope.type === "global" && node.type === "ThisExpression") {
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95 | return true;
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96 | } else if (node.name === "window") {
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97 | return !isShadowed(scope, globalScope, node);
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98 | }
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99 |
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100 | return false;
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101 | }
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102 |
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103 | module.exports = {
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104 | getPropertyName,
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105 | findReference,
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106 | isShadowed,
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107 | isGlobalThisReferenceOrGlobalWindow,
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108 | buildMemberExpressionNamespace
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109 | };
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