const Foo = babelHelpers.enhanceClass(function(
  _defineClass,
  _initializeClass,
  _initializeInstance
) {
  _defineClass(
    class Foo {
      constructor() {
        _initializeInstance(this);
      }
    },
    [
      {
        kind: "field",
        key: "num",

        value() {
          return 2;
        },
      },
    ]
  );

  _initializeClass();
});

function _enhanceClass(factory) { var internalSlots = { F: null, elements: null, finishers: null }; factory(internalSlots, function defineClass(F, definitions) { var elements = definitions.map(_createElementDescriptor); elements = _coalesceClassElements(elements); internalSlots.F = F; internalSlots.elements = elements; }, function initializeClassElements() { _initializeClassElements(internalSlots); }, function initializeInsanceElements(O) { _initializeInstanceElements(O, internalSlots); }); return internalSlots.F; }

function _createElementDescriptor(def) { let descriptor; if (def.kind === "method") { descriptor = { value: def.value, writable: true, configurable: true }; } else if (def.kind === "get") { descriptor = { get: def.value, configurable: true }; } else if (def.kind === "set") { descriptor = { set: def.value, configurable: true }; } else if (def.kind === "field") { descriptor = { configurable: true, writable: true }; } var element = { kind: def.kind === "field" ? "field" : "method", key: def.key, placement: def.static ? "static" : def.kind === "field" ? "own" : "prototype", descriptor: descriptor }; if (def.decorators) element.decorators = def.decorators; if (def.kind === "field") element.initializer = def.value; return element; }

function _coalesceGetterSetter(element, other) { if (element.descriptor.get !== undefined) { other.descriptor.get = element.descriptor.get; } else { other.descriptor.set = element.descriptor.set; } }

function _coalesceClassElements(elements) { const newElements = []; for (var i = 0; i < elements.length; i++) { var element = elements[i]; var index = newElements.findIndex(function (other) { return other.kind === element.kind && other.key === element.key && other.placement === element.placement; }); if (element.kind === "method" && index !== -1) { var other = newElements[index]; if (element.decorators && element.decorators.length > 0) { if (other.decorators && other.decorators.length > 0) { throw new ReferenceError(); } other.decorators = element.decorators; } if (_isDataDescriptor(element.descriptor) || _isDataDescriptor(other.descriptor)) { other.descriptor = element.descriptor; } else { _coalesceGetterSetter(element, other); } } else { newElements.push(element); } } return newElements; }

function _isDataDescriptor(desc) { return desc !== undefined && !(desc.value === undefined && desc.writable === undefined); }

function _initializeClassElements(internalSlots) { var F = internalSlots.F; var proto = F.prototype; internalSlots.elements.forEach(function (element) { if (element.kind === "method") { var receiver = element.placement === "static" ? F : proto; _defineClassElement(receiver, element); } }); internalSlots.elements.forEach(function (element) { var placement = element.placement; if (element.kind === "field" && (placement === "static" || placement === "prototype")) { var receiver = placement === "static" ? F : proto; _defineClassElement(receiver, element); } }); }

function _initializeInstanceElements(O, internalSlots) { internalSlots.elements.forEach(function (element) { if (element.kind === "method" && element.placement === "own") { _defineClassElement(O, element); } }); internalSlots.elements.forEach(function (element) { if (element.kind === "field" && element.placement === "own") { _defineClassElement(O, element); } }); }

function _defineClassElement(receiver, element) { if (element.kind === "field") { var initializer = element.initializer; element.descriptor.value = initializer === void 0 ? void 0 : initializer.call(receiver); } Object.defineProperty(receiver, element.key, element.descriptor); }

const Foo = _enhanceClass(function(
  _defineClass,
  _initializeClass,
  _initializeInstance
) {
  _defineClass(
    class Foo {
      constructor() {
        _initializeInstance(this);
      }
    },
    [
      {
        kind: "field",
        key: "num",

        value() {
          return 2;
        },
      },
    ]
  );

  _initializeClass();
});

class Foo {
  constructor() {
    Object.defineProperty(this, "num", {
      configurable: true,
      enumerable: true,
      writable: true,
      value: 2,
    });
  }
}