348 lines
9.8 KiB
JavaScript
348 lines
9.8 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.evaluate = evaluate;
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exports.evaluateTruthy = evaluateTruthy;
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const VALID_OBJECT_CALLEES = ["Number", "String", "Math"];
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const VALID_IDENTIFIER_CALLEES = ["isFinite", "isNaN", "parseFloat", "parseInt", "decodeURI", "decodeURIComponent", "encodeURI", "encodeURIComponent", null, null];
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const INVALID_METHODS = ["random"];
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function isValidObjectCallee(val) {
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return VALID_OBJECT_CALLEES.includes(val);
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}
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function isValidIdentifierCallee(val) {
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return VALID_IDENTIFIER_CALLEES.includes(val);
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}
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function isInvalidMethod(val) {
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return INVALID_METHODS.includes(val);
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}
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function evaluateTruthy() {
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const res = this.evaluate();
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if (res.confident) return !!res.value;
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}
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function deopt(path, state) {
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if (!state.confident) return;
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state.deoptPath = path;
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state.confident = false;
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}
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const Globals = new Map([["undefined", undefined], ["Infinity", Infinity], ["NaN", NaN]]);
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function evaluateCached(path, state) {
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const {
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node
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} = path;
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const {
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seen
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} = state;
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if (seen.has(node)) {
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const existing = seen.get(node);
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if (existing.resolved) {
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return existing.value;
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} else {
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deopt(path, state);
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return;
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}
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} else {
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const item = {
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resolved: false
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};
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seen.set(node, item);
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const val = _evaluate(path, state);
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if (state.confident) {
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item.resolved = true;
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item.value = val;
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}
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return val;
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}
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}
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function _evaluate(path, state) {
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if (!state.confident) return;
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if (path.isSequenceExpression()) {
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const exprs = path.get("expressions");
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return evaluateCached(exprs[exprs.length - 1], state);
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}
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if (path.isStringLiteral() || path.isNumericLiteral() || path.isBooleanLiteral()) {
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return path.node.value;
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}
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if (path.isNullLiteral()) {
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return null;
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}
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if (path.isTemplateLiteral()) {
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return evaluateQuasis(path, path.node.quasis, state);
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}
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if (path.isTaggedTemplateExpression() && path.get("tag").isMemberExpression()) {
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const object = path.get("tag.object");
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const {
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node: {
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name
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}
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} = object;
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const property = path.get("tag.property");
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if (object.isIdentifier() && name === "String" && !path.scope.getBinding(name) && property.isIdentifier() && property.node.name === "raw") {
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return evaluateQuasis(path, path.node.quasi.quasis, state, true);
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}
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}
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if (path.isConditionalExpression()) {
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const testResult = evaluateCached(path.get("test"), state);
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if (!state.confident) return;
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if (testResult) {
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return evaluateCached(path.get("consequent"), state);
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} else {
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return evaluateCached(path.get("alternate"), state);
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}
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}
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if (path.isExpressionWrapper()) {
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return evaluateCached(path.get("expression"), state);
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}
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if (path.isMemberExpression() && !path.parentPath.isCallExpression({
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callee: path.node
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})) {
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const property = path.get("property");
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const object = path.get("object");
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if (object.isLiteral()) {
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const value = object.node.value;
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const type = typeof value;
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let key = null;
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if (path.node.computed) {
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key = evaluateCached(property, state);
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if (!state.confident) return;
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} else if (property.isIdentifier()) {
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key = property.node.name;
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}
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if ((type === "number" || type === "string") && key != null && (typeof key === "number" || typeof key === "string")) {
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return value[key];
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}
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}
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}
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if (path.isReferencedIdentifier()) {
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const binding = path.scope.getBinding(path.node.name);
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if (binding) {
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if (binding.constantViolations.length > 0 || path.node.start < binding.path.node.end) {
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deopt(binding.path, state);
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return;
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}
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if (binding.hasValue) {
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return binding.value;
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}
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}
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const name = path.node.name;
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if (Globals.has(name)) {
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if (!binding) {
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return Globals.get(name);
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}
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deopt(binding.path, state);
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return;
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}
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const resolved = path.resolve();
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if (resolved === path) {
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deopt(path, state);
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return;
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} else {
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return evaluateCached(resolved, state);
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}
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}
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if (path.isUnaryExpression({
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prefix: true
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})) {
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if (path.node.operator === "void") {
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return undefined;
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}
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const argument = path.get("argument");
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if (path.node.operator === "typeof" && (argument.isFunction() || argument.isClass())) {
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return "function";
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}
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const arg = evaluateCached(argument, state);
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if (!state.confident) return;
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switch (path.node.operator) {
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case "!":
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return !arg;
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case "+":
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return +arg;
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case "-":
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return -arg;
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case "~":
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return ~arg;
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case "typeof":
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return typeof arg;
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}
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}
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if (path.isArrayExpression()) {
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const arr = [];
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const elems = path.get("elements");
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for (const elem of elems) {
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const elemValue = elem.evaluate();
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if (elemValue.confident) {
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arr.push(elemValue.value);
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} else {
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deopt(elemValue.deopt, state);
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return;
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}
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}
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return arr;
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}
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if (path.isObjectExpression()) {
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const obj = {};
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const props = path.get("properties");
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for (const prop of props) {
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if (prop.isObjectMethod() || prop.isSpreadElement()) {
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deopt(prop, state);
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return;
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}
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const keyPath = prop.get("key");
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let key;
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if (prop.node.computed) {
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key = keyPath.evaluate();
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if (!key.confident) {
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deopt(key.deopt, state);
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return;
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}
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key = key.value;
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} else if (keyPath.isIdentifier()) {
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key = keyPath.node.name;
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} else {
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key = keyPath.node.value;
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}
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const valuePath = prop.get("value");
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let value = valuePath.evaluate();
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if (!value.confident) {
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deopt(value.deopt, state);
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return;
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}
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value = value.value;
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obj[key] = value;
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}
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return obj;
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}
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if (path.isLogicalExpression()) {
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const wasConfident = state.confident;
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const left = evaluateCached(path.get("left"), state);
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const leftConfident = state.confident;
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state.confident = wasConfident;
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const right = evaluateCached(path.get("right"), state);
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const rightConfident = state.confident;
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switch (path.node.operator) {
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case "||":
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state.confident = leftConfident && (!!left || rightConfident);
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if (!state.confident) return;
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return left || right;
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case "&&":
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state.confident = leftConfident && (!left || rightConfident);
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if (!state.confident) return;
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return left && right;
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case "??":
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state.confident = leftConfident && (left != null || rightConfident);
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if (!state.confident) return;
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return left != null ? left : right;
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}
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}
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if (path.isBinaryExpression()) {
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const left = evaluateCached(path.get("left"), state);
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if (!state.confident) return;
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const right = evaluateCached(path.get("right"), state);
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if (!state.confident) return;
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switch (path.node.operator) {
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case "-":
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return left - right;
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case "+":
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return left + right;
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case "/":
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return left / right;
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case "*":
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return left * right;
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case "%":
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return left % right;
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case "**":
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return Math.pow(left, right);
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case "<":
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return left < right;
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case ">":
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return left > right;
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case "<=":
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return left <= right;
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case ">=":
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return left >= right;
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case "==":
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return left == right;
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case "!=":
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return left != right;
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case "===":
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return left === right;
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case "!==":
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return left !== right;
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case "|":
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return left | right;
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case "&":
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return left & right;
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case "^":
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return left ^ right;
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case "<<":
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return left << right;
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case ">>":
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return left >> right;
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case ">>>":
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return left >>> right;
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}
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}
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if (path.isCallExpression()) {
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const callee = path.get("callee");
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let context;
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let func;
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if (callee.isIdentifier() && !path.scope.getBinding(callee.node.name) && (isValidObjectCallee(callee.node.name) || isValidIdentifierCallee(callee.node.name))) {
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func = global[callee.node.name];
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}
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if (callee.isMemberExpression()) {
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const object = callee.get("object");
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const property = callee.get("property");
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if (object.isIdentifier() && property.isIdentifier() && isValidObjectCallee(object.node.name) && !isInvalidMethod(property.node.name)) {
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context = global[object.node.name];
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const key = property.node.name;
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if (Object.hasOwnProperty.call(context, key)) {
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func = context[key];
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}
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}
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if (object.isLiteral() && property.isIdentifier()) {
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const type = typeof object.node.value;
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if (type === "string" || type === "number") {
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context = object.node.value;
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func = context[property.node.name];
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}
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}
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}
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if (func) {
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const args = path.get("arguments").map(arg => evaluateCached(arg, state));
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if (!state.confident) return;
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return func.apply(context, args);
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}
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}
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deopt(path, state);
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}
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function evaluateQuasis(path, quasis, state, raw = false) {
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let str = "";
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let i = 0;
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const exprs = path.isTemplateLiteral() ? path.get("expressions") : path.get("quasi.expressions");
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for (const elem of quasis) {
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if (!state.confident) break;
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str += raw ? elem.value.raw : elem.value.cooked;
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const expr = exprs[i++];
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if (expr) str += String(evaluateCached(expr, state));
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}
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if (!state.confident) return;
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return str;
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}
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function evaluate() {
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const state = {
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confident: true,
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deoptPath: null,
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seen: new Map()
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};
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let value = evaluateCached(this, state);
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if (!state.confident) value = undefined;
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return {
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confident: state.confident,
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deopt: state.deoptPath,
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value: value
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};
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}
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//# sourceMappingURL=evaluation.js.map
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