Fix bad Scope#parent caching (#6155)

* Fix bad Scope#parent caching

Now, we traverse the path until we find a parent scope.

Fixes #6057.

* Fix bad merge

* Remove cached data

* I need to stop using Github editor

* Fix infinite loops due to scopable paths being moved up

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-expanded/actual.js

@@ -0,0 +1,9 @@
+import args from 'utils/url/args';
+
+export default class App extends Component {
+  exportType = ''
+
+  componentDidMount() {
+    this.exportType = args.get('type', window.location.href);
+  }
+}

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-expanded/expected.js

@@ -0,0 +1,56 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+
+var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };
+
+var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
+
+var _args = require("utils/url/args");
+
+var _args2 = _interopRequireDefault(_args);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }
+
+var App = function (_Component) {
+  _inherits(App, _Component);
+
+  function App() {
+    var _ref;
+
+    var _temp, _this;
+
+    _classCallCheck(this, App);
+
+    for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
+      args[_key] = arguments[_key];
+    }
+
+    return _possibleConstructorReturn(_this, (_temp = _this = _possibleConstructorReturn(this, (_ref = App.__proto__ || Object.getPrototypeOf(App)).call.apply(_ref, [this].concat(args))), Object.defineProperty(_this, "exportType", {
+      configurable: true,
+      enumerable: true,
+      writable: true,
+      value: ''
+    }), _temp));
+  }
+
+  _createClass(App, [{
+    key: "componentDidMount",
+    value: function componentDidMount() {
+      this.exportType = _args2.default.get('type', window.location.href);
+    }
+  }]);
+
+  return App;
+}(Component);
+
+exports.default = App;

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-expanded/options.json

@@ -0,0 +1,4 @@
+{
+  "presets": ["es2015"],
+  "plugins": ["transform-class-properties"]
+}

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-simple/actual.js

@@ -0,0 +1,5 @@
+const a = 'bar';
+function foo(...a) {
+  return a;
+}
+

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-simple/expected.js

@@ -0,0 +1,9 @@
+const a = 'bar';
+
+function foo() {
+  for (var _len = arguments.length, a = Array(_len), _key = 0; _key < _len; _key++) {
+    a[_key] = arguments[_key];
+  }
+
+  return a;
+}

packages/babel-plugin-transform-es2015-parameters/test/fixtures/regression/6057-simple/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-es2015-parameters"]
+}

packages/babel-traverse/src/path/index.js

@@ -105,14 +105,7 @@ export default class NodePath {
   }
 
   getScope(scope: Scope) {
-    let ourScope = scope;
-
-    // we're entering a new scope so let's construct it!
-    if (this.isScope()) {
-      ourScope = new Scope(this, scope);
-    }
-
-    return ourScope;
+    return this.isScope() ? new Scope(this) : scope;
   }
 
   setData(key: string, val: any): any {

packages/babel-traverse/src/scope/index.js

@@ -16,25 +16,6 @@ import { scope as scopeCache } from "../cache";
 // See `warnOnFlowBinding`.
 let _crawlCallsCount = 0;
 
-/**
- * To avoid creating a new Scope instance for each traversal, we maintain a cache on the
- * node itself containing all scopes it has been associated with.
- */
-
-function getCache(path, parentScope, self) {
-  const scopes: Array<Scope> = scopeCache.get(path.node) || [];
-
-  for (const scope of scopes) {
-    if (scope.parent === parentScope && scope.path === path) return scope;
-  }
-
-  scopes.push(self);
-
-  if (!scopeCache.has(path.node)) {
-    scopeCache.set(path.node, scopes);
-  }
-}
-
 // Recursively gathers the identifying names of a node.
 function gatherNodeParts(node: Object, parts: Array) {
   if (t.isModuleDeclaration(node)) {
@@ -181,20 +162,19 @@ export default class Scope {
    * within.
    */
 
-  constructor(path: NodePath, parentScope?: Scope) {
-    if (parentScope && parentScope.block === path.node) {
-      return parentScope;
+  constructor(path: NodePath) {
+    const { node } = path;
+    const cached = scopeCache.get(node);
+    // Sometimes, a scopable path is placed higher in the AST tree.
+    // In these cases, have to create a new Scope.
+    if (cached && cached.path === path) {
+      return cached;
     }
-
-    const cached = getCache(path, parentScope, this);
-    if (cached) return cached;
+    scopeCache.set(node, this);
 
     this.uid = uid++;
-    this.parent = parentScope;
-    this.hub = path.hub;
 
-    this.parentBlock = path.parent;
-    this.block = path.node;
+    this.block = node;
     this.path = path;
 
     this.labels = new Map();
@@ -212,6 +192,19 @@ export default class Scope {
 
   static contextVariables = ["arguments", "undefined", "Infinity", "NaN"];
 
+  get parent() {
+    const parent = this.path.findParent(p => p.isScope());
+    return parent && parent.scope;
+  }
+
+  get parentBlock() {
+    return this.path.parent;
+  }
+
+  get hub() {
+    return this.path.hub;
+  }
+
   /**
    * Traverse node with current scope and path.
    */