404 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			404 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| "use strict";
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| 
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| Object.defineProperty(exports, "__esModule", {
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|   value: true
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| });
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| exports.evaluateTruthy = evaluateTruthy;
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| exports.evaluate = evaluate;
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| const VALID_CALLEES = ["String", "Number", "Math"];
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| const INVALID_METHODS = ["random"];
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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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| 
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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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| 
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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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| 
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|   if (seen.has(node)) {
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|     const existing = seen.get(node);
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| 
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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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| 
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|     const val = _evaluate(path, state);
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| 
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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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| 
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|     return val;
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|   }
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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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|   const {
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|     node
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|   } = path;
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| 
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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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| 
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|   if (path.isStringLiteral() || path.isNumericLiteral() || path.isBooleanLiteral()) {
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|     return node.value;
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|   }
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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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| 
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|   if (path.isTemplateLiteral()) {
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|     return evaluateQuasis(path, node.quasis, state);
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|   }
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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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| 
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|     if (object.isIdentifier() && name === "String" && !path.scope.getBinding(name, true) && property.isIdentifier && property.node.name === "raw") {
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|       return evaluateQuasis(path, node.quasi.quasis, state, true);
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|     }
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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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| 
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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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| 
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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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| 
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|   if (path.isMemberExpression() && !path.parentPath.isCallExpression({
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|     callee: 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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| 
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|     if (object.isLiteral() && property.isIdentifier()) {
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|       const value = object.node.value;
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|       const type = typeof value;
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| 
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|       if (type === "number" || type === "string") {
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|         return value[property.node.name];
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|       }
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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(node.name);
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| 
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|     if (binding && binding.constantViolations.length > 0) {
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|       return deopt(binding.path, state);
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|     }
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| 
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|     if (binding && path.node.start < binding.path.node.end) {
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|       return deopt(binding.path, state);
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|     }
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| 
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|     if (binding && binding.hasValue) {
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|       return binding.value;
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|     } else {
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|       if (node.name === "undefined") {
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|         return binding ? deopt(binding.path, state) : undefined;
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|       } else if (node.name === "Infinity") {
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|         return binding ? deopt(binding.path, state) : Infinity;
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|       } else if (node.name === "NaN") {
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|         return binding ? deopt(binding.path, state) : NaN;
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|       }
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| 
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|       const resolved = path.resolve();
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| 
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|       if (resolved === path) {
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|         return deopt(path, state);
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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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|   }
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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 (node.operator === "void") {
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|       return undefined;
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|     }
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| 
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|     const argument = path.get("argument");
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| 
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|     if (node.operator === "typeof" && (argument.isFunction() || argument.isClass())) {
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|       return "function";
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|     }
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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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| 
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|     switch (node.operator) {
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|       case "!":
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|         return !arg;
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| 
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|       case "+":
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|         return +arg;
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| 
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|       case "-":
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|         return -arg;
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| 
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|       case "~":
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|         return ~arg;
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| 
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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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| 
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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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| 
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|     for (const elem of elems) {
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|       const elemValue = elem.evaluate();
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| 
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|       if (elemValue.confident) {
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|         arr.push(elemValue.value);
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|       } else {
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|         return deopt(elem, state);
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|       }
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|     }
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| 
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|     return arr;
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|   }
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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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| 
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|     for (const prop of props) {
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|       if (prop.isObjectMethod() || prop.isSpreadElement()) {
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|         return deopt(prop, state);
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|       }
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| 
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|       const keyPath = prop.get("key");
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|       let key = keyPath;
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| 
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|       if (prop.node.computed) {
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|         key = key.evaluate();
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| 
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|         if (!key.confident) {
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|           return deopt(keyPath, state);
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|         }
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| 
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|         key = key.value;
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|       } else if (key.isIdentifier()) {
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|         key = key.node.name;
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|       } else {
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|         key = key.node.value;
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|       }
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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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| 
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|       if (!value.confident) {
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|         return deopt(valuePath, state);
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|       }
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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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| 
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|     return obj;
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|   }
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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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| 
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|     switch (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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| 
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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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|     }
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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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| 
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|     switch (node.operator) {
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|       case "-":
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|         return left - right;
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| 
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|       case "+":
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|         return left + right;
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| 
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|       case "/":
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|         return left / right;
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| 
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|       case "*":
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|         return left * right;
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| 
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|       case "%":
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|         return left % right;
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| 
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|       case "**":
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|         return Math.pow(left, right);
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| 
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|       case "<":
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|         return left < right;
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| 
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|       case ">":
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|         return left > right;
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| 
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|       case "<=":
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|         return left <= right;
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| 
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|       case ">=":
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|         return left >= right;
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| 
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|       case "==":
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|         return left == right;
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| 
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|       case "!=":
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|         return left != right;
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| 
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|       case "===":
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|         return left === right;
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| 
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|       case "!==":
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|         return left !== right;
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| 
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|       case "|":
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|         return left | right;
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| 
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|       case "&":
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|         return left & right;
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| 
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|       case "^":
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|         return left ^ right;
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| 
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|       case "<<":
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|         return left << right;
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| 
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|       case ">>":
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|         return left >> right;
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| 
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|       case ">>>":
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|         return left >>> right;
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|     }
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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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| 
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|     if (callee.isIdentifier() && !path.scope.getBinding(callee.node.name, true) && VALID_CALLEES.indexOf(callee.node.name) >= 0) {
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|       func = global[node.callee.name];
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|     }
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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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| 
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|       if (object.isIdentifier() && property.isIdentifier() && VALID_CALLEES.indexOf(object.node.name) >= 0 && INVALID_METHODS.indexOf(property.node.name) < 0) {
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|         context = global[object.node.name];
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|         func = context[property.node.name];
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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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| 
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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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| 
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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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| 
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|   deopt(path, state);
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| }
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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.get("expressions");
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| 
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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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| 
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|   if (!state.confident) return;
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|   return str;
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| }
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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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| } |