prepack/lib/evaluators/UpdateExpression.js

Execute a JS bundle, serialize global state and side effects to a snapshot that can be quickly restored.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});

exports.default = function (ast, strictCode, env, realm) {
  // ECMA262 12.4 Update Expressions

  // Let expr be the result of evaluating UnaryExpression.
  let expr = env.evaluate(ast.argument, strictCode);

  // Let oldValue be ? ToNumber(? GetValue(expr)).
  let oldExpr = _singletons.Environment.GetValue(realm, expr);
  if (oldExpr instanceof _index2.AbstractValue) {
    if (!_singletons.To.IsToNumberPure(realm, oldExpr)) {
      let error = new _errors.CompilerDiagnostic("might be a symbol or an object with an unknown valueOf or toString or Symbol.toPrimitive method", ast.argument.loc, "PP0008", "RecoverableError");
      if (realm.handleError(error) === "Fail") throw new _errors.FatalError();
    }
    (0, _invariant2.default)(ast.operator === "++" || ast.operator === "--"); // As per BabelNodeUpdateExpression
    let op = ast.operator === "++" ? "+" : "-";
    let newAbstractValue = _index2.AbstractValue.createFromBinaryOp(realm, op, oldExpr, new _index2.NumberValue(realm, 1), ast.loc);
    _singletons.Properties.PutValue(realm, expr, newAbstractValue);
    if (ast.prefix) {
      return newAbstractValue;
    } else {
      return oldExpr;
    }
  }
  let oldValue = _singletons.To.ToNumber(realm, oldExpr);

  if (ast.prefix) {
    if (ast.operator === "++") {
      // ECMA262 12.4.6.1

      // 3. Let newValue be the result of adding the value 1 to oldValue, using the same rules as for the + operator (see 12.8.5)
      let newValue = (0, _index.Add)(realm, oldValue, 1);

      // 4. Perform ? PutValue(expr, newValue).
      _singletons.Properties.PutValue(realm, expr, newValue);

      // 5. Return newValue.
      return newValue;
    } else if (ast.operator === "--") {
      // ECMA262 12.4.7.1

      // 3. Let newValue be the result of subtracting the value 1 from oldValue, using the same rules as for the - operator (see 12.8.5).
      let newValue = (0, _index.Add)(realm, oldValue, -1);

      // 4. Perform ? PutValue(expr, newValue).
      _singletons.Properties.PutValue(realm, expr, newValue);

      // 5. Return newValue.
      return newValue;
    }
    (0, _invariant2.default)(false);
  } else {
    if (ast.operator === "++") {
      // ECMA262 12.4.4.1

      // 3. Let newValue be the result of adding the value 1 to oldValue, using the same rules as for the + operator (see 12.8.5).
      let newValue = (0, _index.Add)(realm, oldValue, 1);

      // 4. Perform ? PutValue(lhs, newValue).
      _singletons.Properties.PutValue(realm, expr, newValue);

      // 5. Return oldValue.
      return _index2.IntegralValue.createFromNumberValue(realm, oldValue);
    } else if (ast.operator === "--") {
      // ECMA262 12.4.5.1

      // 3. Let newValue be the result of subtracting the value 1 from oldValue, using the same rules as for the - operator (see 12.8.5).
      let newValue = (0, _index.Add)(realm, oldValue, -1);

      // 4. Perform ? PutValue(lhs, newValue).
      _singletons.Properties.PutValue(realm, expr, newValue);

      // 5. Return oldValue.
      return _index2.IntegralValue.createFromNumberValue(realm, oldValue);
    }
    (0, _invariant2.default)(false);
  }
};

var _errors = require("../errors.js");

var _index = require("../methods/index.js");

var _index2 = require("../values/index.js");

var _singletons = require("../singletons.js");

var _invariant = require("../invariant.js");

var _invariant2 = _interopRequireDefault(_invariant);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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