canonical/node_modules/babel-traverse/lib/scope/index.js

Canonical code style linter and formatter for JavaScript, SCSS, CSS and JSON.

"use strict";

var _classCallCheck = require("babel-runtime/helpers/class-call-check")["default"];

var _Symbol = require("babel-runtime/core-js/symbol")["default"];

var _getIterator = require("babel-runtime/core-js/get-iterator")["default"];

var _Object$create = require("babel-runtime/core-js/object/create")["default"];

var _interopRequireDefault = require("babel-runtime/helpers/interop-require-default")["default"];

var _interopRequireWildcard = require("babel-runtime/helpers/interop-require-wildcard")["default"];

exports.__esModule = true;

var _lodashCollectionIncludes = require("lodash/collection/includes");

var _lodashCollectionIncludes2 = _interopRequireDefault(_lodashCollectionIncludes);

var _repeating = require("repeating");

var _repeating2 = _interopRequireDefault(_repeating);

var _libRenamer = require("./lib/renamer");

var _libRenamer2 = _interopRequireDefault(_libRenamer);

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

var _index2 = _interopRequireDefault(_index);

var _lodashObjectDefaults = require("lodash/object/defaults");

var _lodashObjectDefaults2 = _interopRequireDefault(_lodashObjectDefaults);

var _babelMessages = require("babel-messages");

var messages = _interopRequireWildcard(_babelMessages);

var _binding = require("./binding");

var _binding2 = _interopRequireDefault(_binding);

var _globals = require("globals");

var _globals2 = _interopRequireDefault(_globals);

var _babelTypes = require("babel-types");

var t = _interopRequireWildcard(_babelTypes);

//

/*:: import type NodePath from "../path";*/var CACHE_SINGLE_KEY = _Symbol();
var CACHE_MULTIPLE_KEY = _Symbol();

/**
 * 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.
 *
 * We also optimise for the case of there being only a single scope associated with a node.
 */

function getCache(node, parentScope, self) {
  var singleCache = node[CACHE_SINGLE_KEY];

  if (singleCache) {
    // we've only ever associated one scope with this node so let's check it
    if (matchesParent(singleCache, parentScope)) {
      return singleCache;
    }
  } else if (!node[CACHE_MULTIPLE_KEY]) {
    // no scope has ever been associated with this node
    node[CACHE_SINGLE_KEY] = self;
    return;
  }

  // looks like we have either a single scope association that was never matched or
  // multiple assocations, let's find the right one!
  return getCacheMultiple(node, parentScope, self, singleCache);
}

function matchesParent(scope, parentScope) {
  if (scope.parent === parentScope) {
    return true;
  }
}

function getCacheMultiple(node, parentScope, self, singleCache) {
  var scopes /*: Array<Scope>*/ = node[CACHE_MULTIPLE_KEY] = node[CACHE_MULTIPLE_KEY] || [];

  if (singleCache) {
    // we have a scope assocation miss so push it onto our scopes
    scopes.push(singleCache);
    node[CACHE_SINGLE_KEY] = null;
  }

  // loop through and check each scope to see if it matches our parent
  for (var _iterator = scopes, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _getIterator(_iterator);;) {
    var _ref;

    if (_isArray) {
      if (_i >= _iterator.length) break;
      _ref = _iterator[_i++];
    } else {
      _i = _iterator.next();
      if (_i.done) break;
      _ref = _i.value;
    }

    var scope = _ref;

    if (matchesParent(scope, parentScope)) return scope;
  }

  scopes.push(self);
}

//

var collectorVisitor = {
  For: function For(path) {
    for (var _iterator2 = (t.FOR_INIT_KEYS /*: Array*/), _isArray2 = Array.isArray(_iterator2), _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : _getIterator(_iterator2);;) {
      var _ref2;

      if (_isArray2) {
        if (_i2 >= _iterator2.length) break;
        _ref2 = _iterator2[_i2++];
      } else {
        _i2 = _iterator2.next();
        if (_i2.done) break;
        _ref2 = _i2.value;
      }

      var key = _ref2;

      var declar = path.get(key);
      if (declar.isVar()) path.scope.getFunctionParent().registerBinding("var", declar);
    }
  },

  Declaration: function Declaration(path) {
    // delegate block scope handling to the `blockVariableVisitor`
    if (path.isBlockScoped()) return;

    // this will be hit again once we traverse into it after this iteration
    if (path.isExportDeclaration() && path.get("declaration").isDeclaration()) return;

    // we've ran into a declaration!
    path.scope.getFunctionParent().registerDeclaration(path);
  },

  ReferencedIdentifier: function ReferencedIdentifier(path, state) {
    state.references.push(path);
  },

  ForXStatement: function ForXStatement(path, state) {
    var left = path.get("left");
    if (left.isPattern() || left.isIdentifier()) {
      state.constantViolations.push(left);
    }
  },

  ExportDeclaration: {
    exit: function exit(_ref20) {
      var node = _ref20.node;
      var scope = _ref20.scope;

      var declar = node.declaration;
      if (t.isClassDeclaration(declar) || t.isFunctionDeclaration(declar)) {
        var _id = declar.id;
        if (!_id) return;

        var binding = scope.getBinding(_id.name);
        if (binding) binding.reference();
      } else if (t.isVariableDeclaration(declar)) {
        for (var _iterator3 = (declar.declarations /*: Array<Object>*/), _isArray3 = Array.isArray(_iterator3), _i3 = 0, _iterator3 = _isArray3 ? _iterator3 : _getIterator(_iterator3);;) {
          var _ref3;

          if (_isArray3) {
            if (_i3 >= _iterator3.length) break;
            _ref3 = _iterator3[_i3++];
          } else {
            _i3 = _iterator3.next();
            if (_i3.done) break;
            _ref3 = _i3.value;
          }

          var decl = _ref3;

          var ids = t.getBindingIdentifiers(decl);
          for (var _name in ids) {
            var binding = scope.getBinding(_name);
            if (binding) binding.reference();
          }
        }
      }
    }
  },

  LabeledStatement: function LabeledStatement(path) {
    path.scope.getProgramParent().addGlobal(path.node);
    path.scope.getBlockParent().registerDeclaration(path);
  },

  AssignmentExpression: function AssignmentExpression(path, state) {
    state.assignments.push(path);
  },

  UpdateExpression: function UpdateExpression(path, state) {
    state.constantViolations.push(path.get("argument"));
  },

  UnaryExpression: function UnaryExpression(path, state) {
    if (path.node.operator === "delete") {
      state.constantViolations.push(path.get("argument"));
    }
  },

  BlockScoped: function BlockScoped(path) {
    var scope = path.scope;
    if (scope.path === path) scope = scope.parent;
    scope.getBlockParent().registerDeclaration(path);
  },

  ClassDeclaration: function ClassDeclaration(path) {
    var id = path.node.id;
    if (!id) return;

    var name = id.name;
    path.scope.bindings[name] = path.scope.getBinding(name);
  },

  Block: function Block(path) {
    var paths = path.get("body");
    for (var _iterator4 = (paths /*: Array*/), _isArray4 = Array.isArray(_iterator4), _i4 = 0, _iterator4 = _isArray4 ? _iterator4 : _getIterator(_iterator4);;) {
      var _ref4;

      if (_isArray4) {
        if (_i4 >= _iterator4.length) break;
        _ref4 = _iterator4[_i4++];
      } else {
        _i4 = _iterator4.next();
        if (_i4.done) break;
        _ref4 = _i4.value;
      }

      var bodyPath = _ref4;

      if (bodyPath.isFunctionDeclaration()) {
        path.scope.getBlockParent().registerDeclaration(bodyPath);
      }
    }
  }
};

var uid = 0;

var Scope = (function () {

  /**
   * This searches the current "scope" and collects all references/bindings
   * within.
   */

  function Scope(path /*: NodePath*/, parentScope /*:: ?: Scope*/) {
    _classCallCheck(this, Scope);

    if (parentScope && parentScope.block === path.node) {
      return parentScope;
    }

    var cached = getCache(path.node, parentScope, this);
    if (cached) return cached;

    this.uid = uid++;
    this.parent = parentScope;
    this.hub = path.hub;

    this.parentBlock = path.parent;
    this.block = path.node;
    this.path = path;
  }

  /**
   * Globals.
   */

  /**
   * Traverse node with current scope and path.
   */

  Scope.prototype.traverse = function traverse(node /*: Object*/, opts /*: Object*/, state /*:: ?*/) {
    _index2["default"](node, opts, this, state, this.path);
  };

  /**
   * Generate a unique identifier and add it to the current scope.
   */

  Scope.prototype.generateDeclaredUidIdentifier = function generateDeclaredUidIdentifier() {
    var name /*: string*/ = arguments.length <= 0 || arguments[0] === undefined ? "temp" : arguments[0];

    var id = this.generateUidIdentifier(name);
    this.push({ id: id });
    return id;
  };

  /**
   * Generate a unique identifier.
   */

  Scope.prototype.generateUidIdentifier = function generateUidIdentifier() {
    var name /*: string*/ = arguments.length <= 0 || arguments[0] === undefined ? "temp" : arguments[0];

    return t.identifier(this.generateUid(name));
  };

  /**
   * Generate a unique `_id1` binding.
   */

  Scope.prototype.generateUid = function generateUid() {
    var name /*: string*/ = arguments.length <= 0 || arguments[0] === undefined ? "temp" : arguments[0];

    name = t.toIdentifier(name).replace(/^_+/, "").replace(/[0-9]+$/g, "");

    var uid = undefined;
    var i = 0;
    do {
      uid = this._generateUid(name, i);
      i++;
    } while (this.hasBinding(uid) || this.hasGlobal(uid) || this.hasReference(uid));

    var program = this.getProgramParent();
    program.references[uid] = true;
    program.uids[uid] = true;

    return uid;
  };

  /**
   * Generate an `_id1`.
   */

  Scope.prototype._generateUid = function _generateUid(name, i) {
    var id = name;
    if (i > 1) id += i;
    return "_" + id;
  };

  /**
   * Generate a unique identifier based on a node.
   */

  Scope.prototype.generateUidIdentifierBasedOnNode = function generateUidIdentifierBasedOnNode(parent /*: Object*/, defaultName /*:: ?: String*/) /*:  Object*/ {
    var node = parent;

    if (t.isAssignmentExpression(parent)) {
      node = parent.left;
    } else if (t.isVariableDeclarator(parent)) {
      node = parent.id;
    } else if (t.isObjectProperty(node) || t.isObjectMethod(node)) {
      node = node.key;
    }

    var parts = [];

    var add = function add(node) {
      if (t.isModuleDeclaration(node)) {
        if (node.source) {
          add(node.source);
        } else if (node.specifiers && node.specifiers.length) {
          for (var _iterator5 = (node.specifiers /*: Array*/), _isArray5 = Array.isArray(_iterator5), _i5 = 0, _iterator5 = _isArray5 ? _iterator5 : _getIterator(_iterator5);;) {
            var _ref5;

            if (_isArray5) {
              if (_i5 >= _iterator5.length) break;
              _ref5 = _iterator5[_i5++];
            } else {
              _i5 = _iterator5.next();
              if (_i5.done) break;
              _ref5 = _i5.value;
            }

            var specifier = _ref5;

            add(specifier);
          }
        } else if (node.declaration) {
          add(node.declaration);
        }
      } else if (t.isModuleSpecifier(node)) {
        add(node.local);
      } else if (t.isMemberExpression(node)) {
        add(node.object);
        add(node.property);
      } else if (t.isIdentifier(node)) {
        parts.push(node.name);
      } else if (t.isLiteral(node)) {
        parts.push(node.value);
      } else if (t.isCallExpression(node)) {
        add(node.callee);
      } else if (t.isObjectExpression(node) || t.isObjectPattern(node)) {
        for (var _iterator6 = (node.properties /*: Array*/), _isArray6 = Array.isArray(_iterator6), _i6 = 0, _iterator6 = _isArray6 ? _iterator6 : _getIterator(_iterator6);;) {
          var _ref6;

          if (_isArray6) {
            if (_i6 >= _iterator6.length) break;
            _ref6 = _iterator6[_i6++];
          } else {
            _i6 = _iterator6.next();
            if (_i6.done) break;
            _ref6 = _i6.value;
          }

          var prop = _ref6;

          add(prop.key || prop.argument);
        }
      }
    };

    add(node);

    var id = parts.join("$");
    id = id.replace(/^_/, "") || defaultName || "ref";

    return this.generateUidIdentifier(id.slice(0, 20));
  };

  /**
   * Determine whether evaluating the specific input `node` is a consequenceless reference. ie.
   * evaluating it wont result in potentially arbitrary code from being ran. The following are
   * whitelisted and determined not to cause side effects:
   *
   *  - `this` expressions
   *  - `super` expressions
   *  - Bound identifiers
   */

  Scope.prototype.isStatic = function isStatic(node /*: Object*/) /*: boolean*/ {
    if (t.isThisExpression(node) || t.isSuper(node)) {
      return true;
    }

    if (t.isIdentifier(node)) {
      var binding = this.getBinding(node.name);
      if (binding) {
        return binding.constant;
      } else {
        return this.hasBinding(node.name);
      }
    }

    return false;
  };

  /**
   * Possibly generate a memoised identifier if it is not static and has consequences.
   */

  Scope.prototype.maybeGenerateMemoised = function maybeGenerateMemoised(node /*: Object*/, dontPush /*:: ?: boolean*/) /*: ?Object*/ {
    if (this.isStatic(node)) {
      return null;
    } else {
      var _id2 = this.generateUidIdentifierBasedOnNode(node);
      if (!dontPush) this.push({ id: _id2 });
      return _id2;
    }
  };

  Scope.prototype.checkBlockScopedCollisions = function checkBlockScopedCollisions(local, kind /*: string*/, name /*: string*/, id /*: Object*/) {
    // ignore parameters
    if (kind === "param") return;

    // ignore hoisted functions if there's also a local let
    if (kind === "hoisted" && local.kind === "let") return;

    var duplicate = false;

    // don't allow duplicate bindings to exist alongside
    if (!duplicate) duplicate = kind === "let" || local.kind === "let" || local.kind === "const" || local.kind === "module";

    // don't allow a local of param with a kind of let
    if (!duplicate) duplicate = local.kind === "param" && (kind === "let" || kind === "const");

    if (duplicate) {
      throw this.hub.file.buildCodeFrameError(id, messages.get("scopeDuplicateDeclaration", name), TypeError);
    }
  };

  Scope.prototype.rename = function rename(oldName /*: string*/, newName /*: string*/, block /*:: ?*/) {
    var binding = this.getBinding(oldName);
    if (binding) {
      newName = newName || this.generateUidIdentifier(oldName).name;
      return new _libRenamer2["default"](binding, oldName, newName).rename(block);
    }
  };

  Scope.prototype._renameFromMap = function _renameFromMap(map, oldName, newName, value) {
    if (map[oldName]) {
      map[newName] = value;
      map[oldName] = null;
    }
  };

  Scope.prototype.dump = function dump() {
    var sep = _repeating2["default"]("-", 60);
    console.log(sep);
    var scope = this;
    do {
      console.log("#", scope.block.type);
      for (var _name2 in scope.bindings) {
        var binding = scope.bindings[_name2];
        console.log(" -", _name2, {
          constant: binding.constant,
          references: binding.references,
          violations: binding.constantViolations.length,
          kind: binding.kind
        });
      }
    } while (scope = scope.parent);
    console.log(sep);
  };

  Scope.prototype.toArray = function toArray(node /*: Object*/, i /*:: ?: number*/) {
    var file = this.hub.file;

    if (t.isIdentifier(node)) {
      var binding = this.getBinding(node.name);
      if (binding && binding.constant && binding.path.isGenericType("Array")) return node;
    }

    if (t.isArrayExpression(node)) {
      return node;
    }

    if (t.isIdentifier(node, { name: "arguments" })) {
      return t.callExpression(t.memberExpression(t.memberExpression(t.memberExpression(t.identifier("Array"), t.identifier("prototype")), t.identifier("slice")), t.identifier("call")), [node]);
    }

    var helperName = "toArray";
    var args = [node];
    if (i === true) {
      helperName = "toConsumableArray";
    } else if (i) {
      args.push(t.numericLiteral(i));
      helperName = "slicedToArray";
      // TODO if (this.hub.file.isLoose("es6.forOf")) helperName += "-loose";
    }
    return t.callExpression(file.addHelper(helperName), args);
  };

  Scope.prototype.registerDeclaration = function registerDeclaration(path /*: NodePath*/) {
    if (path.isLabeledStatement()) {
      this.registerBinding("label", path);
    } else if (path.isFunctionDeclaration()) {
      this.registerBinding("hoisted", path.get("id"), path);
    } else if (path.isVariableDeclaration()) {
      var declarations = path.get("declarations");
      for (var _iterator7 = (declarations /*: Array*/), _isArray7 = Array.isArray(_iterator7), _i7 = 0, _iterator7 = _isArray7 ? _iterator7 : _getIterator(_iterator7);;) {
        var _ref7;

        if (_isArray7) {
          if (_i7 >= _iterator7.length) break;
          _ref7 = _iterator7[_i7++];
        } else {
          _i7 = _iterator7.next();
          if (_i7.done) break;
          _ref7 = _i7.value;
        }

        var declar = _ref7;

        this.registerBinding(path.node.kind, declar);
      }
    } else if (path.isClassDeclaration()) {
      this.registerBinding("let", path);
    } else if (path.isImportDeclaration()) {
      var specifiers = path.get("specifiers");
      for (var _iterator8 = (specifiers /*: Array*/), _isArray8 = Array.isArray(_iterator8), _i8 = 0, _iterator8 = _isArray8 ? _iterator8 : _getIterator(_iterator8);;) {
        var _ref8;

        if (_isArray8) {
          if (_i8 >= _iterator8.length) break;
          _ref8 = _iterator8[_i8++];
        } else {
          _i8 = _iterator8.next();
          if (_i8.done) break;
          _ref8 = _i8.value;
        }

        var specifier = _ref8;

        this.registerBinding("module", specifier);
      }
    } else if (path.isExportDeclaration()) {
      var declar = path.get("declaration");
      if (declar.isClassDeclaration() || declar.isFunctionDeclaration() || declar.isVariableDeclaration()) {
        this.registerDeclaration(declar);
      }
    } else {
      this.registerBinding("unknown", path);
    }
  };

  Scope.prototype.buildUndefinedNode = function buildUndefinedNode() {
    if (this.hasBinding("undefined")) {
      return t.unaryExpression("void", t.numericLiteral(0), true);
    } else {
      return t.identifier("undefined");
    }
  };

  Scope.prototype.registerConstantViolation = function registerConstantViolation(path /*: NodePath*/) {
    var ids = path.getBindingIdentifiers();
    for (var _name3 in ids) {
      var binding = this.getBinding(_name3);
      if (binding) binding.reassign(path);
    }
  };

  Scope.prototype.registerBinding = function registerBinding(kind /*: string*/, path /*: NodePath*/) {
    var bindingPath = arguments.length <= 2 || arguments[2] === undefined ? path : arguments[2];
    return (function () {
      if (!kind) throw new ReferenceError("no `kind`");

      if (path.isVariableDeclaration()) {
        var declarators /*: Array<NodePath>*/ = path.get("declarations");
        for (var _iterator9 = declarators, _isArray9 = Array.isArray(_iterator9), _i9 = 0, _iterator9 = _isArray9 ? _iterator9 : _getIterator(_iterator9);;) {
          var _ref9;

          if (_isArray9) {
            if (_i9 >= _iterator9.length) break;
            _ref9 = _iterator9[_i9++];
          } else {
            _i9 = _iterator9.next();
            if (_i9.done) break;
            _ref9 = _i9.value;
          }

          var declar = _ref9;

          this.registerBinding(kind, declar);
        }
        return;
      }

      var parent = this.getProgramParent();
      var ids = path.getBindingIdentifiers(true);

      for (var _name4 in ids) {
        for (var _iterator10 = (ids[_name4] /*: Array<Object>*/), _isArray10 = Array.isArray(_iterator10), _i10 = 0, _iterator10 = _isArray10 ? _iterator10 : _getIterator(_iterator10);;) {
          var _ref10;

          if (_isArray10) {
            if (_i10 >= _iterator10.length) break;
            _ref10 = _iterator10[_i10++];
          } else {
            _i10 = _iterator10.next();
            if (_i10.done) break;
            _ref10 = _i10.value;
          }

          var _id3 = _ref10;

          var local = this.getOwnBinding(_name4);
          if (local) {
            // same identifier so continue safely as we're likely trying to register it
            // multiple times
            if (local.identifier === _id3) continue;

            this.checkBlockScopedCollisions(local, kind, _name4, _id3);
          }

          parent.references[_name4] = true;

          this.bindings[_name4] = new _binding2["default"]({
            identifier: _id3,
            existing: local,
            scope: this,
            path: bindingPath,
            kind: kind
          });
        }
      }
    }).apply(this, arguments);
  };

  Scope.prototype.addGlobal = function addGlobal(node /*: Object*/) {
    this.globals[node.name] = node;
  };

  Scope.prototype.hasUid = function hasUid(name) /*: boolean*/ {
    var scope = this;

    do {
      if (scope.uids[name]) return true;
    } while (scope = scope.parent);

    return false;
  };

  Scope.prototype.hasGlobal = function hasGlobal(name /*: string*/) /*: boolean*/ {
    var scope = this;

    do {
      if (scope.globals[name]) return true;
    } while (scope = scope.parent);

    return false;
  };

  Scope.prototype.hasReference = function hasReference(name /*: string*/) /*: boolean*/ {
    var scope = this;

    do {
      if (scope.references[name]) return true;
    } while (scope = scope.parent);

    return false;
  };

  Scope.prototype.isPure = function isPure(node, constantsOnly /*:: ?: boolean*/) {
    if (t.isIdentifier(node)) {
      var binding = this.getBinding(node.name);
      if (!binding) return false;
      if (constantsOnly) return binding.constant;
      return true;
    } else if (t.isClass(node)) {
      if (node.superClass && !this.isPure(node.superClass, constantsOnly)) return false;
      return this.isPure(node.body, constantsOnly);
    } else if (t.isClassBody(node)) {
      for (var _iterator11 = node.body, _isArray11 = Array.isArray(_iterator11), _i11 = 0, _iterator11 = _isArray11 ? _iterator11 : _getIterator(_iterator11);;) {
        var _ref11;

        if (_isArray11) {
          if (_i11 >= _iterator11.length) break;
          _ref11 = _iterator11[_i11++];
        } else {
          _i11 = _iterator11.next();
          if (_i11.done) break;
          _ref11 = _i11.value;
        }

        var method = _ref11;

        if (!this.isPure(method, constantsOnly)) return false;
      }
      return true;
    } else if (t.isBinary(node)) {
      return this.isPure(node.left, constantsOnly) && this.isPure(node.right, constantsOnly);
    } else if (t.isArrayExpression(node)) {
      for (var _iterator12 = (node.elements /*: Array<Object>*/), _isArray12 = Array.isArray(_iterator12), _i12 = 0, _iterator12 = _isArray12 ? _iterator12 : _getIterator(_iterator12);;) {
        var _ref12;

        if (_isArray12) {
          if (_i12 >= _iterator12.length) break;
          _ref12 = _iterator12[_i12++];
        } else {
          _i12 = _iterator12.next();
          if (_i12.done) break;
          _ref12 = _i12.value;
        }

        var elem = _ref12;

        if (!this.isPure(elem, constantsOnly)) return false;
      }
      return true;
    } else if (t.isObjectExpression(node)) {
      for (var _iterator13 = (node.properties /*: Array<Object>*/), _isArray13 = Array.isArray(_iterator13), _i13 = 0, _iterator13 = _isArray13 ? _iterator13 : _getIterator(_iterator13);;) {
        var _ref13;

        if (_isArray13) {
          if (_i13 >= _iterator13.length) break;
          _ref13 = _iterator13[_i13++];
        } else {
          _i13 = _iterator13.next();
          if (_i13.done) break;
          _ref13 = _i13.value;
        }

        var prop = _ref13;

        if (!this.isPure(prop, constantsOnly)) return false;
      }
      return true;
    } else if (t.isClassMethod(node)) {
      if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
      if (node.kind === "get" || node.kind === "set") return false;
      return true;
    } else if (t.isClassProperty(node) || t.isObjectProperty(node)) {
      if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
      return this.isPure(node.value, constantsOnly);
    } else if (t.isUnaryExpression(node)) {
      return this.isPure(node.argument, constantsOnly);
    } else {
      return t.isPureish(node);
    }
  };

  /**
   * Set some arbitrary data on the current scope.
   */

  Scope.prototype.setData = function setData(key, val) {
    return this.data[key] = val;
  };

  /**
   * Recursively walk up scope tree looking for the data `key`.
   */

  Scope.prototype.getData = function getData(key) {
    var scope = this;
    do {
      var data = scope.data[key];
      if (data != null) return data;
    } while (scope = scope.parent);
  };

  /**
   * Recursively walk up scope tree looking for the data `key` and if it exists,
   * remove it.
   */

  Scope.prototype.removeData = function removeData(key) {
    var scope = this;
    do {
      var data = scope.data[key];
      if (data != null) scope.data[key] = null;
    } while (scope = scope.parent);
  };

  Scope.prototype.init = function init() {
    if (!this.references) this.crawl();
  };

  Scope.prototype.crawl = function crawl() {
    var path = this.path;

    //

    this.references = _Object$create(null);
    this.bindings = _Object$create(null);
    this.globals = _Object$create(null);
    this.uids = _Object$create(null);
    this.data = _Object$create(null);

    // ForStatement - left, init

    if (path.isLoop()) {
      for (var _iterator14 = (t.FOR_INIT_KEYS /*: Array<string>*/), _isArray14 = Array.isArray(_iterator14), _i14 = 0, _iterator14 = _isArray14 ? _iterator14 : _getIterator(_iterator14);;) {
        var _ref14;

        if (_isArray14) {
          if (_i14 >= _iterator14.length) break;
          _ref14 = _iterator14[_i14++];
        } else {
          _i14 = _iterator14.next();
          if (_i14.done) break;
          _ref14 = _i14.value;
        }

        var key = _ref14;

        var node = path.get(key);
        if (node.isBlockScoped()) this.registerBinding(node.node.kind, node);
      }
    }

    // FunctionExpression - id

    if (path.isFunctionExpression() && path.has("id")) {
      if (!path.get("id").node[t.NOT_LOCAL_BINDING]) {
        this.registerBinding("local", path.get("id"), path);
      }
    }

    // Class

    if (path.isClassExpression() && path.has("id")) {
      if (!path.get("id").node[t.NOT_LOCAL_BINDING]) {
        this.registerBinding("local", path);
      }
    }

    // Function - params, rest

    if (path.isFunction()) {
      var params /*: Array<NodePath>*/ = path.get("params");
      for (var _iterator15 = params, _isArray15 = Array.isArray(_iterator15), _i15 = 0, _iterator15 = _isArray15 ? _iterator15 : _getIterator(_iterator15);;) {
        var _ref15;

        if (_isArray15) {
          if (_i15 >= _iterator15.length) break;
          _ref15 = _iterator15[_i15++];
        } else {
          _i15 = _iterator15.next();
          if (_i15.done) break;
          _ref15 = _i15.value;
        }

        var param = _ref15;

        this.registerBinding("param", param);
      }
    }

    // CatchClause - param

    if (path.isCatchClause()) {
      this.registerBinding("let", path);
    }

    // Program

    var parent = this.getProgramParent();
    if (parent.crawling) return;

    var state = {
      references: [],
      constantViolations: [],
      assignments: []
    };

    this.crawling = true;
    path.traverse(collectorVisitor, state);
    this.crawling = false;

    // register assignments
    for (var _iterator16 = state.assignments, _isArray16 = Array.isArray(_iterator16), _i16 = 0, _iterator16 = _isArray16 ? _iterator16 : _getIterator(_iterator16);;) {
      var _ref16;

      if (_isArray16) {
        if (_i16 >= _iterator16.length) break;
        _ref16 = _iterator16[_i16++];
      } else {
        _i16 = _iterator16.next();
        if (_i16.done) break;
        _ref16 = _i16.value;
      }

      var _path = _ref16;

      // register undeclared bindings as globals
      var ids = _path.getBindingIdentifiers();
      var programParent = undefined;
      for (var _name5 in ids) {
        if (_path.scope.getBinding(_name5)) continue;

        programParent = programParent || _path.scope.getProgramParent();
        programParent.addGlobal(ids[_name5]);
      }

      // register as constant violation
      _path.scope.registerConstantViolation(_path);
    }

    // register references
    for (var _iterator17 = state.references, _isArray17 = Array.isArray(_iterator17), _i17 = 0, _iterator17 = _isArray17 ? _iterator17 : _getIterator(_iterator17);;) {
      var _ref17;

      if (_isArray17) {
        if (_i17 >= _iterator17.length) break;
        _ref17 = _iterator17[_i17++];
      } else {
        _i17 = _iterator17.next();
        if (_i17.done) break;
        _ref17 = _i17.value;
      }

      var ref = _ref17;

      var binding = ref.scope.getBinding(ref.node.name);
      if (binding) {
        binding.reference(ref);
      } else {
        ref.scope.getProgramParent().addGlobal(ref.node);
      }
    }

    // register constant violations
    for (var _iterator18 = state.constantViolations, _isArray18 = Array.isArray(_iterator18), _i18 = 0, _iterator18 = _isArray18 ? _iterator18 : _getIterator(_iterator18);;) {
      var _ref18;

      if (_isArray18) {
        if (_i18 >= _iterator18.length) break;
        _ref18 = _iterator18[_i18++];
      } else {
        _i18 = _iterator18.next();
        if (_i18.done) break;
        _ref18 = _i18.value;
      }

      var _path2 = _ref18;

      _path2.scope.registerConstantViolation(_path2);
    }
  };

  Scope.prototype.push = function push(opts /*: {
                                                id: Object;
                                                init: ?Object;
                                                unique: ?boolean;
                                                _blockHoist: ?number;
                                                kind: "var" | "let";
                                              }*/) {
    var path = this.path;

    if (!path.isBlockStatement() && !path.isProgram()) {
      path = this.getBlockParent().path;
    }

    if (path.isSwitchStatement()) {
      path = this.getFunctionParent().path;
    }

    if (path.isLoop() || path.isCatchClause() || path.isFunction()) {
      t.ensureBlock(path.node);
      path = path.get("body");
    }

    var unique = opts.unique;
    var kind = opts.kind || "var";
    var blockHoist = opts._blockHoist == null ? 2 : opts._blockHoist;

    var dataKey = "declaration:" + kind + ":" + blockHoist;
    var declarPath = !unique && path.getData(dataKey);

    if (!declarPath) {
      var declar = t.variableDeclaration(kind, []);
      declar._generated = true;
      declar._blockHoist = blockHoist;

      var _path$unshiftContainer = path.unshiftContainer("body", [declar]);

      declarPath = _path$unshiftContainer[0];

      if (!unique) path.setData(dataKey, declarPath);
    }

    var declarator = t.variableDeclarator(opts.id, opts.init);
    declarPath.node.declarations.push(declarator);
    this.registerBinding(kind, declarPath.get("declarations").pop());
  };

  /**
   * Walk up to the top of the scope tree and get the `Program`.
   */

  Scope.prototype.getProgramParent = function getProgramParent() {
    var scope = this;
    do {
      if (scope.path.isProgram()) {
        return scope;
      }
    } while (scope = scope.parent);
    throw new Error("We couldn't find a Function or Program...");
  };

  /**
   * Walk up the scope tree until we hit either a Function or reach the
   * very top and hit Program.
   */

  Scope.prototype.getFunctionParent = function getFunctionParent() {
    var scope = this;
    do {
      if (scope.path.isFunctionParent()) {
        return scope;
      }
    } while (scope = scope.parent);
    throw new Error("We couldn't find a Function or Program...");
  };

  /**
   * Walk up the scope tree until we hit either a BlockStatement/Loop/Program/Function/Switch or reach the
   * very top and hit Program.
   */

  Scope.prototype.getBlockParent = function getBlockParent() {
    var scope = this;
    do {
      if (scope.path.isBlockParent()) {
        return scope;
      }
    } while (scope = scope.parent);
    throw new Error("We couldn't find a BlockStatement, For, Switch, Function, Loop or Program...");
  };

  /**
   * Walks the scope tree and gathers **all** bindings.
   */

  Scope.prototype.getAllBindings = function getAllBindings() /*: Object*/ {
    var ids = _Object$create(null);

    var scope = this;
    do {
      _lodashObjectDefaults2["default"](ids, scope.bindings);
      scope = scope.parent;
    } while (scope);

    return ids;
  };

  /**
   * Walks the scope tree and gathers all declarations of `kind`.
   */

  Scope.prototype.getAllBindingsOfKind = function getAllBindingsOfKind() /*: Object*/ {
    var ids = _Object$create(null);

    for (var _iterator19 = (arguments /*: Array*/), _isArray19 = Array.isArray(_iterator19), _i19 = 0, _iterator19 = _isArray19 ? _iterator19 : _getIterator(_iterator19);;) {
      var _ref19;

      if (_isArray19) {
        if (_i19 >= _iterator19.length) break;
        _ref19 = _iterator19[_i19++];
      } else {
        _i19 = _iterator19.next();
        if (_i19.done) break;
        _ref19 = _i19.value;
      }

      var kind = _ref19;

      var scope = this;
      do {
        for (var _name6 in scope.bindings) {
          var binding = scope.bindings[_name6];
          if (binding.kind === kind) ids[_name6] = binding;
        }
        scope = scope.parent;
      } while (scope);
    }

    return ids;
  };

  Scope.prototype.bindingIdentifierEquals = function bindingIdentifierEquals(name /*: string*/, node /*: Object*/) /*: boolean*/ {
    return this.getBindingIdentifier(name) === node;
  };

  Scope.prototype.getBinding = function getBinding(name /*: string*/) {
    var scope = this;

    do {
      var binding = scope.getOwnBinding(name);
      if (binding) return binding;
    } while (scope = scope.parent);
  };

  Scope.prototype.getOwnBinding = function getOwnBinding(name /*: string*/) {
    return this.bindings[name];
  };

  Scope.prototype.getBindingIdentifier = function getBindingIdentifier(name /*: string*/) {
    var info = this.getBinding(name);
    return info && info.identifier;
  };

  Scope.prototype.getOwnBindingIdentifier = function getOwnBindingIdentifier(name /*: string*/) {
    var binding = this.bindings[name];
    return binding && binding.identifier;
  };

  Scope.prototype.hasOwnBinding = function hasOwnBinding(name /*: string*/) {
    return !!this.getOwnBinding(name);
  };

  Scope.prototype.hasBinding = function hasBinding(name /*: string*/, noGlobals /*:: ?*/) {
    if (!name) return false;
    if (this.hasOwnBinding(name)) return true;
    if (this.parentHasBinding(name, noGlobals)) return true;
    if (this.hasUid(name)) return true;
    if (!noGlobals && _lodashCollectionIncludes2["default"](Scope.globals, name)) return true;
    if (!noGlobals && _lodashCollectionIncludes2["default"](Scope.contextVariables, name)) return true;
    return false;
  };

  Scope.prototype.parentHasBinding = function parentHasBinding(name /*: string*/, noGlobals /*:: ?*/) {
    return this.parent && this.parent.hasBinding(name, noGlobals);
  };

  /**
   * Move a binding of `name` to another `scope`.
   */

  Scope.prototype.moveBindingTo = function moveBindingTo(name, scope) {
    var info = this.getBinding(name);
    if (info) {
      info.scope.removeOwnBinding(name);
      info.scope = scope;
      scope.bindings[name] = info;
    }
  };

  Scope.prototype.removeOwnBinding = function removeOwnBinding(name /*: string*/) {
    delete this.bindings[name];
  };

  Scope.prototype.removeBinding = function removeBinding(name /*: string*/) {
    // clear literal binding
    var info = this.getBinding(name);
    if (info) {
      info.scope.removeOwnBinding(name);
    }

    // clear uids with this name - https://github.com/babel/babel/issues/2101
    var scope = this;
    do {
      if (scope.uids[name]) {
        scope.uids[name] = false;
      }
    } while (scope = scope.parent);
  };

  return Scope;
})();

exports["default"] = Scope;
module.exports = exports["default"];

/**
 * Variables available in current context.
 */