index.js 5.3 KB

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  1. 'use strict';
  2. var acorn = require('acorn');
  3. var walk = require('acorn/dist/walk');
  4. function isScope(node) {
  5. return node.type === 'FunctionExpression' || node.type === 'FunctionDeclaration' || node.type === 'ArrowFunctionExpression' || node.type === 'Program';
  6. }
  7. function isBlockScope(node) {
  8. return node.type === 'BlockStatement' || isScope(node);
  9. }
  10. function declaresArguments(node) {
  11. return node.type === 'FunctionExpression' || node.type === 'FunctionDeclaration';
  12. }
  13. function declaresThis(node) {
  14. return node.type === 'FunctionExpression' || node.type === 'FunctionDeclaration';
  15. }
  16. function reallyParse(source) {
  17. try {
  18. return acorn.parse(source, {
  19. ecmaVersion: 6,
  20. allowReturnOutsideFunction: true,
  21. allowImportExportEverywhere: true,
  22. allowHashBang: true
  23. });
  24. } catch (ex) {
  25. return acorn.parse(source, {
  26. ecmaVersion: 5,
  27. allowReturnOutsideFunction: true,
  28. allowImportExportEverywhere: true,
  29. allowHashBang: true
  30. });
  31. }
  32. }
  33. module.exports = findGlobals;
  34. module.exports.parse = reallyParse;
  35. function findGlobals(source) {
  36. var globals = [];
  37. var ast;
  38. // istanbul ignore else
  39. if (typeof source === 'string') {
  40. ast = reallyParse(source);
  41. } else {
  42. ast = source;
  43. }
  44. // istanbul ignore if
  45. if (!(ast && typeof ast === 'object' && ast.type === 'Program')) {
  46. throw new TypeError('Source must be either a string of JavaScript or an acorn AST');
  47. }
  48. var declareFunction = function (node) {
  49. var fn = node;
  50. fn.locals = fn.locals || {};
  51. node.params.forEach(function (node) {
  52. declarePattern(node, fn);
  53. });
  54. if (node.id) {
  55. fn.locals[node.id.name] = true;
  56. }
  57. }
  58. var declarePattern = function (node, parent) {
  59. switch (node.type) {
  60. case 'Identifier':
  61. parent.locals[node.name] = true;
  62. break;
  63. case 'ObjectPattern':
  64. node.properties.forEach(function (node) {
  65. declarePattern(node.value, parent);
  66. });
  67. break;
  68. case 'ArrayPattern':
  69. node.elements.forEach(function (node) {
  70. if (node) declarePattern(node, parent);
  71. });
  72. break;
  73. case 'RestElement':
  74. declarePattern(node.argument, parent);
  75. break;
  76. case 'AssignmentPattern':
  77. declarePattern(node.left, parent);
  78. break;
  79. // istanbul ignore next
  80. default:
  81. throw new Error('Unrecognized pattern type: ' + node.type);
  82. }
  83. }
  84. var declareModuleSpecifier = function (node, parents) {
  85. ast.locals = ast.locals || {};
  86. ast.locals[node.local.name] = true;
  87. }
  88. walk.ancestor(ast, {
  89. 'VariableDeclaration': function (node, parents) {
  90. var parent = null;
  91. for (var i = parents.length - 1; i >= 0 && parent === null; i--) {
  92. if (node.kind === 'var' ? isScope(parents[i]) : isBlockScope(parents[i])) {
  93. parent = parents[i];
  94. }
  95. }
  96. parent.locals = parent.locals || {};
  97. node.declarations.forEach(function (declaration) {
  98. declarePattern(declaration.id, parent);
  99. });
  100. },
  101. 'FunctionDeclaration': function (node, parents) {
  102. var parent = null;
  103. for (var i = parents.length - 2; i >= 0 && parent === null; i--) {
  104. if (isScope(parents[i])) {
  105. parent = parents[i];
  106. }
  107. }
  108. parent.locals = parent.locals || {};
  109. parent.locals[node.id.name] = true;
  110. declareFunction(node);
  111. },
  112. 'Function': declareFunction,
  113. 'ClassDeclaration': function (node, parents) {
  114. var parent = null;
  115. for (var i = parents.length - 2; i >= 0 && parent === null; i--) {
  116. if (isScope(parents[i])) {
  117. parent = parents[i];
  118. }
  119. }
  120. parent.locals = parent.locals || {};
  121. parent.locals[node.id.name] = true;
  122. },
  123. 'TryStatement': function (node) {
  124. if (node.handler === null) return;
  125. node.handler.body.locals = node.handler.body.locals || {};
  126. node.handler.body.locals[node.handler.param.name] = true;
  127. },
  128. 'ImportDefaultSpecifier': declareModuleSpecifier,
  129. 'ImportSpecifier': declareModuleSpecifier,
  130. 'ImportNamespaceSpecifier': declareModuleSpecifier
  131. });
  132. function identifier(node, parents) {
  133. var name = node.name;
  134. if (name === 'undefined') return;
  135. for (var i = 0; i < parents.length; i++) {
  136. if (name === 'arguments' && declaresArguments(parents[i])) {
  137. return;
  138. }
  139. if (parents[i].locals && name in parents[i].locals) {
  140. return;
  141. }
  142. }
  143. if (
  144. parents[parents.length - 2] &&
  145. parents[parents.length - 2].type === 'TryStatement' &&
  146. parents[parents.length - 2].handler &&
  147. node === parents[parents.length - 2].handler.param
  148. ) {
  149. return;
  150. }
  151. node.parents = parents;
  152. globals.push(node);
  153. }
  154. walk.ancestor(ast, {
  155. 'VariablePattern': identifier,
  156. 'Identifier': identifier,
  157. 'ThisExpression': function (node, parents) {
  158. for (var i = 0; i < parents.length; i++) {
  159. if (declaresThis(parents[i])) {
  160. return;
  161. }
  162. }
  163. node.parents = parents;
  164. globals.push(node);
  165. }
  166. });
  167. var groupedGlobals = {};
  168. globals.forEach(function (node) {
  169. groupedGlobals[node.name] = (groupedGlobals[node.name] || []);
  170. groupedGlobals[node.name].push(node);
  171. });
  172. return Object.keys(groupedGlobals).sort().map(function (name) {
  173. return {name: name, nodes: groupedGlobals[name]};
  174. });
  175. }