evaluation.js 10 KB

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  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", {
  3. value: true
  4. });
  5. exports.evaluateTruthy = evaluateTruthy;
  6. exports.evaluate = evaluate;
  7. var VALID_CALLEES = ["String", "Number", "Math"];
  8. var INVALID_METHODS = ["random"];
  9. function evaluateTruthy() {
  10. var res = this.evaluate();
  11. if (res.confident) return !!res.value;
  12. }
  13. function deopt(path, state) {
  14. if (!state.confident) return;
  15. state.deoptPath = path;
  16. state.confident = false;
  17. }
  18. function evaluateCached(path, state) {
  19. var node = path.node;
  20. var seen = state.seen;
  21. if (seen.has(node)) {
  22. var existing = seen.get(node);
  23. if (existing.resolved) {
  24. return existing.value;
  25. } else {
  26. deopt(path, state);
  27. return;
  28. }
  29. } else {
  30. var item = {
  31. resolved: false
  32. };
  33. seen.set(node, item);
  34. var val = _evaluate(path, state);
  35. if (state.confident) {
  36. item.resolved = true;
  37. item.value = val;
  38. }
  39. return val;
  40. }
  41. }
  42. function _evaluate(path, state) {
  43. if (!state.confident) return;
  44. var node = path.node;
  45. if (path.isSequenceExpression()) {
  46. var exprs = path.get("expressions");
  47. return evaluateCached(exprs[exprs.length - 1], state);
  48. }
  49. if (path.isStringLiteral() || path.isNumericLiteral() || path.isBooleanLiteral()) {
  50. return node.value;
  51. }
  52. if (path.isNullLiteral()) {
  53. return null;
  54. }
  55. if (path.isTemplateLiteral()) {
  56. return evaluateQuasis(path, node.quasis, state);
  57. }
  58. if (path.isTaggedTemplateExpression() && path.get("tag").isMemberExpression()) {
  59. var object = path.get("tag.object");
  60. var name = object.node.name;
  61. var property = path.get("tag.property");
  62. if (object.isIdentifier() && name === "String" && !path.scope.getBinding(name, true) && property.isIdentifier && property.node.name === "raw") {
  63. return evaluateQuasis(path, node.quasi.quasis, state, true);
  64. }
  65. }
  66. if (path.isConditionalExpression()) {
  67. var testResult = evaluateCached(path.get("test"), state);
  68. if (!state.confident) return;
  69. if (testResult) {
  70. return evaluateCached(path.get("consequent"), state);
  71. } else {
  72. return evaluateCached(path.get("alternate"), state);
  73. }
  74. }
  75. if (path.isExpressionWrapper()) {
  76. return evaluateCached(path.get("expression"), state);
  77. }
  78. if (path.isMemberExpression() && !path.parentPath.isCallExpression({
  79. callee: node
  80. })) {
  81. var _property = path.get("property");
  82. var _object = path.get("object");
  83. if (_object.isLiteral() && _property.isIdentifier()) {
  84. var value = _object.node.value;
  85. var type = typeof value;
  86. if (type === "number" || type === "string") {
  87. return value[_property.node.name];
  88. }
  89. }
  90. }
  91. if (path.isReferencedIdentifier()) {
  92. var binding = path.scope.getBinding(node.name);
  93. if (binding && binding.constantViolations.length > 0) {
  94. return deopt(binding.path, state);
  95. }
  96. if (binding && path.node.start < binding.path.node.end) {
  97. return deopt(binding.path, state);
  98. }
  99. if (binding && binding.hasValue) {
  100. return binding.value;
  101. } else {
  102. if (node.name === "undefined") {
  103. return binding ? deopt(binding.path, state) : undefined;
  104. } else if (node.name === "Infinity") {
  105. return binding ? deopt(binding.path, state) : Infinity;
  106. } else if (node.name === "NaN") {
  107. return binding ? deopt(binding.path, state) : NaN;
  108. }
  109. var resolved = path.resolve();
  110. if (resolved === path) {
  111. return deopt(path, state);
  112. } else {
  113. return evaluateCached(resolved, state);
  114. }
  115. }
  116. }
  117. if (path.isUnaryExpression({
  118. prefix: true
  119. })) {
  120. if (node.operator === "void") {
  121. return undefined;
  122. }
  123. var argument = path.get("argument");
  124. if (node.operator === "typeof" && (argument.isFunction() || argument.isClass())) {
  125. return "function";
  126. }
  127. var arg = evaluateCached(argument, state);
  128. if (!state.confident) return;
  129. switch (node.operator) {
  130. case "!":
  131. return !arg;
  132. case "+":
  133. return +arg;
  134. case "-":
  135. return -arg;
  136. case "~":
  137. return ~arg;
  138. case "typeof":
  139. return typeof arg;
  140. }
  141. }
  142. if (path.isArrayExpression()) {
  143. var arr = [];
  144. var elems = path.get("elements");
  145. for (var _iterator = elems, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
  146. var _ref;
  147. if (_isArray) {
  148. if (_i >= _iterator.length) break;
  149. _ref = _iterator[_i++];
  150. } else {
  151. _i = _iterator.next();
  152. if (_i.done) break;
  153. _ref = _i.value;
  154. }
  155. var elem = _ref;
  156. var elemValue = elem.evaluate();
  157. if (elemValue.confident) {
  158. arr.push(elemValue.value);
  159. } else {
  160. return deopt(elem, state);
  161. }
  162. }
  163. return arr;
  164. }
  165. if (path.isObjectExpression()) {
  166. var obj = {};
  167. var props = path.get("properties");
  168. for (var _iterator2 = props, _isArray2 = Array.isArray(_iterator2), _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : _iterator2[Symbol.iterator]();;) {
  169. var _ref2;
  170. if (_isArray2) {
  171. if (_i2 >= _iterator2.length) break;
  172. _ref2 = _iterator2[_i2++];
  173. } else {
  174. _i2 = _iterator2.next();
  175. if (_i2.done) break;
  176. _ref2 = _i2.value;
  177. }
  178. var prop = _ref2;
  179. if (prop.isObjectMethod() || prop.isSpreadElement()) {
  180. return deopt(prop, state);
  181. }
  182. var keyPath = prop.get("key");
  183. var key = keyPath;
  184. if (prop.node.computed) {
  185. key = key.evaluate();
  186. if (!key.confident) {
  187. return deopt(keyPath, state);
  188. }
  189. key = key.value;
  190. } else if (key.isIdentifier()) {
  191. key = key.node.name;
  192. } else {
  193. key = key.node.value;
  194. }
  195. var valuePath = prop.get("value");
  196. var _value = valuePath.evaluate();
  197. if (!_value.confident) {
  198. return deopt(valuePath, state);
  199. }
  200. _value = _value.value;
  201. obj[key] = _value;
  202. }
  203. return obj;
  204. }
  205. if (path.isLogicalExpression()) {
  206. var wasConfident = state.confident;
  207. var left = evaluateCached(path.get("left"), state);
  208. var leftConfident = state.confident;
  209. state.confident = wasConfident;
  210. var right = evaluateCached(path.get("right"), state);
  211. var rightConfident = state.confident;
  212. state.confident = leftConfident && rightConfident;
  213. switch (node.operator) {
  214. case "||":
  215. if (left && leftConfident) {
  216. state.confident = true;
  217. return left;
  218. }
  219. if (!state.confident) return;
  220. return left || right;
  221. case "&&":
  222. if (!left && leftConfident || !right && rightConfident) {
  223. state.confident = true;
  224. }
  225. if (!state.confident) return;
  226. return left && right;
  227. }
  228. }
  229. if (path.isBinaryExpression()) {
  230. var _left = evaluateCached(path.get("left"), state);
  231. if (!state.confident) return;
  232. var _right = evaluateCached(path.get("right"), state);
  233. if (!state.confident) return;
  234. switch (node.operator) {
  235. case "-":
  236. return _left - _right;
  237. case "+":
  238. return _left + _right;
  239. case "/":
  240. return _left / _right;
  241. case "*":
  242. return _left * _right;
  243. case "%":
  244. return _left % _right;
  245. case "**":
  246. return Math.pow(_left, _right);
  247. case "<":
  248. return _left < _right;
  249. case ">":
  250. return _left > _right;
  251. case "<=":
  252. return _left <= _right;
  253. case ">=":
  254. return _left >= _right;
  255. case "==":
  256. return _left == _right;
  257. case "!=":
  258. return _left != _right;
  259. case "===":
  260. return _left === _right;
  261. case "!==":
  262. return _left !== _right;
  263. case "|":
  264. return _left | _right;
  265. case "&":
  266. return _left & _right;
  267. case "^":
  268. return _left ^ _right;
  269. case "<<":
  270. return _left << _right;
  271. case ">>":
  272. return _left >> _right;
  273. case ">>>":
  274. return _left >>> _right;
  275. }
  276. }
  277. if (path.isCallExpression()) {
  278. var callee = path.get("callee");
  279. var context;
  280. var func;
  281. if (callee.isIdentifier() && !path.scope.getBinding(callee.node.name, true) && VALID_CALLEES.indexOf(callee.node.name) >= 0) {
  282. func = global[node.callee.name];
  283. }
  284. if (callee.isMemberExpression()) {
  285. var _object2 = callee.get("object");
  286. var _property2 = callee.get("property");
  287. if (_object2.isIdentifier() && _property2.isIdentifier() && VALID_CALLEES.indexOf(_object2.node.name) >= 0 && INVALID_METHODS.indexOf(_property2.node.name) < 0) {
  288. context = global[_object2.node.name];
  289. func = context[_property2.node.name];
  290. }
  291. if (_object2.isLiteral() && _property2.isIdentifier()) {
  292. var _type = typeof _object2.node.value;
  293. if (_type === "string" || _type === "number") {
  294. context = _object2.node.value;
  295. func = context[_property2.node.name];
  296. }
  297. }
  298. }
  299. if (func) {
  300. var args = path.get("arguments").map(function (arg) {
  301. return evaluateCached(arg, state);
  302. });
  303. if (!state.confident) return;
  304. return func.apply(context, args);
  305. }
  306. }
  307. deopt(path, state);
  308. }
  309. function evaluateQuasis(path, quasis, state, raw) {
  310. if (raw === void 0) {
  311. raw = false;
  312. }
  313. var str = "";
  314. var i = 0;
  315. var exprs = path.get("expressions");
  316. for (var _iterator3 = quasis, _isArray3 = Array.isArray(_iterator3), _i3 = 0, _iterator3 = _isArray3 ? _iterator3 : _iterator3[Symbol.iterator]();;) {
  317. var _ref3;
  318. if (_isArray3) {
  319. if (_i3 >= _iterator3.length) break;
  320. _ref3 = _iterator3[_i3++];
  321. } else {
  322. _i3 = _iterator3.next();
  323. if (_i3.done) break;
  324. _ref3 = _i3.value;
  325. }
  326. var elem = _ref3;
  327. if (!state.confident) break;
  328. str += raw ? elem.value.raw : elem.value.cooked;
  329. var expr = exprs[i++];
  330. if (expr) str += String(evaluateCached(expr, state));
  331. }
  332. if (!state.confident) return;
  333. return str;
  334. }
  335. function evaluate() {
  336. var state = {
  337. confident: true,
  338. deoptPath: null,
  339. seen: new Map()
  340. };
  341. var value = evaluateCached(this, state);
  342. if (!state.confident) value = undefined;
  343. return {
  344. confident: state.confident,
  345. deopt: state.deoptPath,
  346. value: value
  347. };
  348. }