separate binding logic from scope to a binding class, move binding type resolution to the path so it can be used on any expression - #653

src/babel/transformation/templates/for-of-array.js

@@ -0,0 +1 @@
+for (var KEY = 0; KEY < ARR.length; KEY++) BODY;

src/babel/transformation/transformers/es6/destructuring.js

@@ -432,7 +432,7 @@ class DestructuringTransformer {
     } else {
       arrayRef = this.scope.generateUidBasedOnNode(arrayRef);
       this.nodes.push(this.buildVariableDeclaration(arrayRef, toArray));
-      this.scope.assignTypeGeneric(arrayRef.name, "Array");
+      this.getBinding(arrayRef.name).assignTypeGeneric("Array");
     }
 
     //

src/babel/transformation/transformers/es6/for-of.js

@@ -5,6 +5,12 @@ import * as t from "../../../types";
 export var check = t.isForOfStatement;
 
 export function ForOfStatement(node, parent, scope, file) {
+  if (this.get("right").isTypeGeneric("Array")) {
+    return array(node, scope, file);
+  }
+
+  //
+
   var callback = spec;
   if (file.isLoose("es6.forOf")) callback = loose;
 
@@ -36,6 +42,44 @@ export function ForOfStatement(node, parent, scope, file) {
   }
 }
 
+var array = function (node, scope, file) {
+  var nodes = [];
+  var right = node.right;
+
+  if (!t.isIdentifier(right) || !scope.hasBinding(right.name)) {
+    var uid = scope.generateUidIdentifier("arr");
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(uid, right)
+    ]));
+    right = uid;
+  }
+
+  var iterationKey = scope.generateUidIdentifier("i");
+
+  var loop = util.template("for-of-array", {
+    BODY: node.body,
+    KEY:  iterationKey,
+    ARR:  right
+  });
+
+  t.inherits(loop, node);
+  t.ensureBlock(loop);
+
+  var iterationValue = t.memberExpression(right, iterationKey, true);
+
+  var left = node.left;
+  if (t.isVariableDeclaration(left)) {
+    left.declarations[0].init = iterationValue;
+    loop.body.body.unshift(left);
+  } else {
+    loop.body.body.unshift(t.expressionStatement(t.assignmentExpression("=", left, iterationValue)));
+  }
+
+  nodes.push(loop);
+
+  return nodes;
+};
+
 var loose = function (node, parent, scope, file) {
   var left = node.left;
   var declar, id;

src/babel/transformation/transformers/es6/parameters.rest.js

@@ -127,8 +127,6 @@ exports.Function = function (node, parent, scope, file) {
     );
   }
 
-  scope.assignTypeGeneric(rest.name, "Array");
-
   var loop = util.template("rest", {
     ARGUMENTS: argsId,
     ARRAY_KEY: arrKey,
@@ -136,7 +134,7 @@ exports.Function = function (node, parent, scope, file) {
     START:     start,
     ARRAY:     rest,
     KEY:       key,
-    LEN: len,
+    LEN:       len
   });
   loop._blockHoist = node.params.length + 1;
   node.body.body.unshift(loop);

src/babel/transformation/transformers/es6/tail-call.js

@@ -142,7 +142,7 @@ class TailCallTransformer {
   hasDeopt() {
     // check if the ownerId has been reassigned, if it has then it's not safe to
     // perform optimisations
-    var ownerIdInfo = this.scope.getBindingInfo(this.ownerId.name);
+    var ownerIdInfo = this.scope.getBinding(this.ownerId.name);
     return ownerIdInfo && ownerIdInfo.reassigned;
   }
 

src/babel/transformation/transformers/index.js

@@ -20,7 +20,6 @@ export default {
   "playground.objectGetterMemoization":    require("./playground/object-getter-memoization"),
 
   reactCompat:                             require("./other/react-compat"),
-  flow:                                    require("./other/flow"),
   react:                                   require("./other/react"),
 
   _modules:                                require("./internal/modules"),
@@ -110,5 +109,6 @@ export default {
   "utility.inlineExpressions":             require("./utility/inline-expressions"),
   "utility.deadCodeElimination":           require("./utility/dead-code-elimination"),
 
+  flow:                                    require("./other/flow"),
   _cleanUp:                                require("./internal/cleanup")
 };

src/babel/traversal/binding.js

@@ -0,0 +1,92 @@
+import * as t from "../types";
+
+export default class Binding {
+  constructor({ identifier, scope, path, kind }) {
+    this.identifier = identifier;
+    this.reassigned = false;
+    this.scope      = scope;
+    this.path       = path;
+    this.kind       = kind;
+  }
+
+  /**
+   * Description
+   */
+
+   setTypeAnnotation() {
+    var typeInfo = this.path.getTypeAnnotation();
+    this.typeAnnotationInferred = typeInfo.inferred;
+    this.typeAnnotation         = typeInfo.annotation;
+   }
+
+  /**
+   * Description
+   */
+
+  isTypeGeneric(): boolean {
+    return this.path.isTypeGeneric(...arguments);
+  }
+
+  /**
+   * Description
+   */
+
+  assignTypeGeneric(type: Object, params?) {
+    var typeParams = null;
+    if (params) params = t.typeParameterInstantiation(params);
+    this.assignType(t.genericTypeAnnotation(t.identifier(type), typeParams));
+  }
+
+  /**
+   * Description
+   */
+
+  assignType(type: Object) {
+    this.typeAnnotation = type;
+  }
+
+  /**
+   * Description
+   */
+
+  reassign() {
+    this.reassigned = true;
+
+    if (this.typeAnnotationInferred) {
+      // destroy the inferred typeAnnotation
+      this.typeAnnotation = null;
+    }
+  }
+
+  /**
+   * Description
+   */
+
+  getValueIfImmutable() {
+    // can't guarantee this value is the same
+    if (this.reassigned) return;
+
+    var node = this.path.node;
+    if (t.isVariableDeclarator(node)) {
+      if (t.isIdentifier(node.id)) {
+        node = node.init;
+      } else {
+        // otherwise it's probably a destructuring like:
+        // var { foo } = "foo";
+        return;
+      }
+    }
+
+    if (t.isImmutable(node)) {
+      return node;
+    }
+  }
+
+  /**
+   * Description
+   */
+
+  isCompatibleWithType(newType): boolean {
+    return false;
+  }
+}

src/babel/traversal/index.js

@@ -42,7 +42,6 @@ traverse.node = function (node, opts, scope, state, parentPath) {
 function clearNode(node) {
   node._declarations = null;
   node.extendedRange = null;
-  node._scopeInfo    = null;
   node._paths        = null;
   node.tokens        = null;
   node.range         = null;

src/babel/traversal/path.js

@@ -1,3 +1,7 @@
+import isBoolean from "lodash/lang/isBoolean";
+import isNumber from "lodash/lang/isNumber";
+import isRegExp from "lodash/lang/isRegExp";
+import isString from "lodash/lang/isString";
 import traverse from "./index";
 import includes from "lodash/collection/includes";
 import Scope from "./scope";
@@ -200,7 +204,104 @@ export default class TraversalPath {
   }
 
   get(key) {
-    return TraversalPath.get(this, this.context, this.node, this.node, key);
+    var node = this.node;
+    var container = node[key];
+    if (Array.isArray(container)) {
+      return container.map((_, i) => {
+        return TraversalPath.get(this, this.context, node, container, i);
+      });
+    } else {
+      return TraversalPath.get(this, this.context, node, node, key);
+    }
+  }
+
+  has(key) {
+    return !!this.node[key];
+  }
+
+  getTypeAnnotation(): Object {
+    if (this.typeInfo) {
+      return this.typeInfo;
+    }
+
+    var info = this.typeInfo = {
+      inferred: false,
+      annotation: null
+    };
+
+    var type = this.node.typeAnnotation;
+
+    if (!type) {
+      info.inferred = true;
+      type = this.inferType(this);
+    }
+
+    if (type) {
+      if (t.isTypeAnnotation(type)) type = type.typeAnnotation;
+      info.annotation = type;
+    }
+
+    return info;
+  }
+
+  resolve(): ?TraversalPath {
+    if (this.isVariableDeclarator()) {
+      return this.get("init").resolve();
+    } else if (this.isIdentifier()) {
+      var binding = this.scope.getBinding(this.node.name);
+      if (!binding) return;
+
+      if (binding.path === this) {
+        return this;
+      } else {
+        return binding.path.resolve();;
+      }
+    } else if (this.isMemberExpression()) {
+      var targetKey = t.toComputedKey(this.node);
+      if (!t.isLiteral(targetKey)) return;
+      var targetName = targetKey.value;
+
+      var target = this.get("object").resolve();
+      if (!target || !target.isObjectExpression()) return;
+
+      var props = target.get("properties");
+      for (var i = 0; i < props.length; i++) {
+        var prop = props[i];
+        if (!prop.isProperty()) continue;
+
+        var key = prop.get("key");
+        if (key.isIdentifier({ name: targetName }) || key.isLiteral({ value: targetName })) {
+          return prop.get("value");
+        }
+      }
+    } else {
+      return this;
+    }
+  }
+
+  inferType(path: TraversalPath) {
+    path = path.resolve();
+    if (!path) return;
+
+    if (path.isRestElement() || path.isArrayExpression()) {
+      return t.genericTypeAnnotation(t.identifier("Array"));
+    }
+
+    if (path.isObjectExpression()) {
+      return t.genericTypeAnnotation(t.identifier("Object"));
+    }
+
+    if (path.isLiteral()) {
+      var value = path.node.value;
+      if (isString(value)) return t.stringTypeAnnotation();
+      if (isNumber(value)) return t.numberTypeAnnotation();
+      if (isBoolean(value)) return t.booleanTypeAnnotation();
+    }
+
+    if (path.isCallExpression()) {
+      var callee = path.get("callee").resolve();
+      if (callee && callee.isFunction()) return callee.node.returnType;
+    }
   }
 
   isScope() {
@@ -215,13 +316,40 @@ export default class TraversalPath {
     return t.isReferenced(this.node, this.parent);
   }
 
+  isBlockScoped() {
+    return t.isBlockScoped(this.node);
+  }
+
+  isVar() {
+    return t.isVar(this.node);
+  }
+
   isScope() {
     return t.isScope(this.node, this.parent);
   }
 
+  isTypeGeneric(genericName: string, hasTypeParameters?): boolean {
+    var type = this.getTypeAnnotation().annotation;
+    if (!type) return false;
+
+    if (!t.isGenericTypeAnnotation(type) || !t.isIdentifier(type.id, { name: genericName })) {
+      return false;
+    }
+
+    if (hasTypeParameters && !type.typeParameters) {
+      return false;
+    }
+
+    return true;
+  }
+
   getBindingIdentifiers() {
     return t.getBindingIdentifiers(this.node);
   }
+
+  traverse(opts, state) {
+    traverse(this.node, opts, this.scope, state);
+  }
 }
 
 for (var i = 0; i < t.TYPES.length; i++) {

src/babel/traversal/scope.js

@@ -2,6 +2,7 @@ import includes from "lodash/collection/includes";
 import traverse from "./index";
 import defaults from "lodash/object/defaults";
 import * as messages from "../messages";
+import Binding from "./binding";
 import globals from "globals";
 import flatten from "lodash/array/flatten";
 import extend from "lodash/object/extend";
@@ -12,27 +13,27 @@ import * as t from "../types";
 var functionVariableVisitor = {
   enter(node, parent, scope, state) {
     if (t.isFor(node)) {
-      each(t.FOR_INIT_KEYS, function (key) {
+      each(t.FOR_INIT_KEYS, (key) => {
-        var declar = node[key];
+        var declar = this.get(key);
-        if (t.isVar(declar)) state.scope.registerBinding("var", declar);
+        if (declar.isVar()) state.scope.registerBinding("var", declar);
       });
     }
 
     // this block is a function so we'll stop since none of the variables
     // declared within are accessible
-    if (t.isFunction(node)) return this.skip();
+    if (this.isFunction()) return this.skip();
 
     // function identifier doesn't belong to this scope
     if (state.blockId && node === state.blockId) return;
 
     // delegate block scope handling to the `blockVariableVisitor`
-    if (t.isBlockScoped(node)) return;
+    if (this.isBlockScoped()) return;
 
     // this will be hit again once we traverse into it after this iteration
-    if (t.isExportDeclaration(node) && t.isDeclaration(node.declaration)) return;
+    if (this.isExportDeclaration() && t.isDeclaration(node.declaration)) return;
 
     // we've ran into a declaration!
-    if (t.isDeclaration(node)) state.scope.registerDeclaration(node);
+    if (this.isDeclaration()) state.scope.registerDeclaration(this);
   }
 };
 
@@ -42,16 +43,20 @@ var programReferenceVisitor = {
       state.addGlobal(node);
     } else if (t.isLabeledStatement(node)) {
       state.addGlobal(node);
-    } else if (t.isAssignmentExpression(node) || t.isUpdateExpression(node) || (t.isUnaryExpression(node) && node.operator === "delete")) {
+    } else if (t.isAssignmentExpression(node)) {
-      scope.registerBindingReassignment(node);
+      scope.registerBindingReassignment(this.get("left"), this.get("right"));
+    } else if (t.isUpdateExpression(node)) {
+      // TODO
+    } else if (t.isUnaryExpression(node) && node.operator === "delete") {
+      scope.registerBindingReassignment(this.get("left"), null);
     }
   }
 };
 
 var blockVariableVisitor = {
   enter(node, parent, scope, state) {
-    if (t.isFunctionDeclaration(node) || t.isBlockScoped(node)) {
+    if (this.isFunctionDeclaration() || this.isBlockScoped()) {
-      state.registerDeclaration(node);
+      state.registerDeclaration(this);
     } else if (t.isScope(node, parent)) {
       this.skip();
     }
@@ -112,9 +117,7 @@ export default class Scope {
    */
 
   generateUidIdentifier(name: string) {
-    var id = t.identifier(this.generateUid(name));
+    return t.identifier(this.generateUid(name));
-    this.getFunctionParent().registerBinding("uid", id);
-    return id;
   }
 
   /**
@@ -129,7 +132,8 @@ export default class Scope {
     do {
       uid = this._generateUid(name, i);
       i++;
-    } while (this.hasBinding(uid) || this.hasGlobal(uid));
+    } while (this.hasBinding(uid) || this.hasGlobal(uid) || this.hasUid(uid));
+    this.uids[uid] = true;
     return uid;
   }
 
@@ -139,6 +143,19 @@ export default class Scope {
     return `_${id}`;
   }
 
+  /**
+   * Description
+   */
+
+  hasUid(name): boolean {
+    var scope = this;
+    do {
+      if (scope.uids[name]) return true;
+      scope = scope.parent;
+    } while (scope);
+    return false;
+  }
+
   /*
    * Description
    */
@@ -217,7 +234,7 @@ export default class Scope {
   rename(oldName: string, newName: string) {
     newName ||= this.generateUidIdentifier(oldName).name;
 
-    var info = this.getBindingInfo(oldName);
+    var info = this.getBinding(oldName);
     if (!info) return;
 
     var binding = info.identifier;
@@ -246,102 +263,6 @@ export default class Scope {
     binding.name = newName;
   }
 
-  /**
-   * Description
-   */
-
-  inferType(node: Object) {
-    var target;
-
-    if (t.isVariableDeclarator(node)) {
-      target = node.init;
-    }
-
-    if (t.isArrayExpression(target)) {
-      return t.genericTypeAnnotation(t.identifier("Array"));
-    }
-
-    if (t.isObjectExpression(target)) {
-      return;
-    }
-
-    if (t.isLiteral(target)) {
-      return;
-    }
-
-    if (t.isCallExpression(target) && t.isIdentifier(target.callee)) {
-      var funcInfo = this.getBindingInfo(target.callee.name);
-      if (funcInfo) {
-        var funcNode = funcInfo.node;
-        return !funcInfo.reassigned && t.isFunction(funcNode) && node.returnType;
-      }
-    }
-
-    if (t.isIdentifier(target)) {
-      return;
-    }
-  }
-
-  /**
-   * Description
-   */
-
-  isTypeGeneric(name: string, genericName: string) {
-    var info = this.getBindingInfo(name);
-    if (!info) return false;
-
-    var type = info.typeAnnotation;
-    return t.isGenericTypeAnnotation(type) && t.isIdentifier(type.id, { name: genericName });
-  }
-
-  /**
-   * Description
-   */
-
-  assignTypeGeneric(name: string, type: Object) {
-    this.assignType(name, t.genericTypeAnnotation(t.identifier(type)));
-  }
-
-  /**
-   * Description
-   */
-
-  assignType(name: string, type: Object) {
-    var info = this.getBindingInfo(name);
-    if (!info) return;
-
-    info.typeAnnotation = type;
-  }
-
-  /**
-   * Description
-   */
-
-  getTypeAnnotation(id: Object, node: Object): Object {
-    var info = {
-      annotation: null,
-      inferred: false
-    };
-
-    var type;
-
-    if (id.typeAnnotation) {
-      type = id.typeAnnotation;
-    }
-
-    if (!type) {
-      info.inferred = true;
-      type = this.inferType(node);
-    }
-
-    if (type) {
-      if (t.isTypeAnnotation(type)) type = type.typeAnnotation;
-      info.annotation = type;
-    }
-
-    return info;
-  }
-
   /**
    * Description
    */
@@ -349,8 +270,9 @@ export default class Scope {
   toArray(node: Object, i?: number) {
     var file = this.file;
 
-    if (t.isIdentifier(node) && this.isTypeGeneric(node.name, "Array")) {
+    if (t.isIdentifier(node)) {
-      return node;
+      var binding = this.getBinding(node.name);
+      if (binding && binding.isTypeGeneric("Array")) return node;
     }
 
     if (t.isArrayExpression(node)) {
@@ -376,33 +298,21 @@ export default class Scope {
    * Description
    */
 
-  refreshDeclaration(node: Object) {
+  registerDeclaration(path: TraversalPath) {
-    if (t.isBlockScoped(node)) {
+    var node = path.node;
-      this.getBlockParent().registerDeclaration(node);
-    } else if (t.isVariableDeclaration(node, { kind: "var" })) {
-      this.getFunctionParent().registerDeclaration(node);
-    } else if (node === this.block) {
-      this.recrawl();
-    }
-  }
-
-  /**
-   * Description
-   */
-
-  registerDeclaration(node: Object) {
     if (t.isFunctionDeclaration(node)) {
-      this.registerBinding("hoisted", node);
+      this.registerBinding("hoisted", path);
     } else if (t.isVariableDeclaration(node)) {
-      for (var i = 0; i < node.declarations.length; i++) {
+      var declarations = path.get("declarations");
-        this.registerBinding(node.kind, node.declarations[i]);
+      for (var i = 0; i < declarations.length; i++) {
+        this.registerBinding(node.kind, declarations[i]);
       }
     } else if (t.isClassDeclaration(node)) {
-      this.registerBinding("let", node);
+      this.registerBinding("let", path);
     } else if (t.isImportDeclaration(node) || t.isExportDeclaration(node)) {
-      this.registerBinding("module", node);
+      this.registerBinding("module", path);
     } else {
-      this.registerBinding("unknown", node);
+      this.registerBinding("unknown", path);
     }
   }
 
@@ -410,18 +320,16 @@ export default class Scope {
    * Description
    */
 
-  registerBindingReassignment(node: Object) {
+  registerBindingReassignment(left: TraversalPath, right: TraversalPath) {
-    var ids = t.getBindingIdentifiers(node);
+    var ids = left.getBindingIdentifiers();
     for (var name in ids) {
-      var info = this.getBindingInfo(name);
+      var binding = this.getBinding(name);
-      if (info) {
+      if (!binding) continue;
-        info.reassigned = true;
+      if (right) {
-
+        var rightType = right.typeAnnotation;
-        if (info.typeAnnotationInferred) {
+        if (rightType && binding.isCompatibleWithType(rightType)) continue;
-          // destroy the inferred typeAnnotation
-          info.typeAnnotation = null;
-        }
       }
+      binding.reassign();
     }
   }
 
@@ -429,27 +337,22 @@ export default class Scope {
    * Description
    */
 
-  registerBinding(kind: string, node: Object) {
+  registerBinding(kind: string, path: TraversalPath) {
     if (!kind) throw new ReferenceError("no `kind`");
 
-    var ids = t.getBindingIdentifiers(node);
+    var ids = path.getBindingIdentifiers();
 
     for (var name in ids) {
       var id = ids[name];
 
       this.checkBlockScopedCollisions(kind, name, id);
 
-      var typeInfo = this.getTypeAnnotation(id, node);
+      this.bindings[name] = new Binding({
-
-      this.bindings[name] = {
-        typeAnnotationInferred: typeInfo.inferred,
-        typeAnnotation:         typeInfo.annotation,
-        reassigned:             false,
         identifier: id,
         scope:      this,
-        node:                   node,
+        path:       path,
         kind:       kind
-      };
+      });
     }
   }
 
@@ -489,91 +392,92 @@ export default class Scope {
    */
 
   crawl() {
-    var block = this.block;
+    var path = this.path;
     var i;
 
     //
 
-    var info = this.path.getData("scopeInfo");
+    var info = path.getData("scopeInfo");
     if (info) {
       extend(this, info);
       return;
     }
 
-    info = this.path.setData("scopeInfo", {
+    info = path.setData("scopeInfo", {
       bindings: object(),
-      globals:  object()
+      globals:  object(),
+      uids:     object()
     });
 
     extend(this, info);
 
     // ForStatement - left, init
 
-    if (t.isLoop(block)) {
+    if (path.isLoop()) {
       for (i = 0; i < t.FOR_INIT_KEYS.length; i++) {
-        var node = block[t.FOR_INIT_KEYS[i]];
+        var node = path.get(t.FOR_INIT_KEYS[i]);
-        if (t.isBlockScoped(node)) this.registerBinding("let", node);
+        if (node.isBlockScoped()) this.registerBinding("let", node);
       }
 
-      if (t.isBlockStatement(block.body)) {
+      var body = path.get("body");
-        block = block.body;
+      if (body.isBlockStatement()) path = path.get("body");
-      }
     }
 
     // FunctionExpression - id
 
-    if (t.isFunctionExpression(block) && block.id) {
+    if (path.isFunctionExpression() && path.has("id")) {
-      if (!t.isProperty(this.parentBlock, { method: true })) {
+      if (!t.isProperty(path.parent, { method: true })) {
-        this.registerBinding("var", block.id);
+        this.registerBinding("var", path.get("id"));
       }
     }
 
     // Class
 
-    if (t.isClass(block) && block.id) {
+    if (path.isClass() && path.has("id")) {
-      this.registerBinding("var", block.id);
+      this.registerBinding("var", path.get("id"));
     }
 
     // Function - params, rest
 
-    if (t.isFunction(block)) {
+    if (path.isFunction()) {
-      for (i = 0; i < block.params.length; i++) {
+      var params = path.get("params");
-        this.registerBinding("param", block.params[i]);
+      for (i = 0; i < params.length; i++) {
+        this.registerBinding("param", params[i]);
       }
-      this.traverse(block.body, blockVariableVisitor, this);
+      this.traverse(path.get("body"), blockVariableVisitor, this);
     }
 
     // Program, BlockStatement, Function - let variables
 
-    if (t.isBlockStatement(block) || t.isProgram(block)) {
+    if (path.isBlockStatement() || path.isProgram()) {
-      this.traverse(block, blockVariableVisitor, this);
+      this.traverse(path.node, blockVariableVisitor, this);
     }
 
     // CatchClause - param
 
-    if (t.isCatchClause(block)) {
+    if (path.isCatchClause()) {
-      this.registerBinding("let", block.param);
+      this.registerBinding("let", path.get("param"));
     }
 
     // ComprehensionExpression - blocks
 
-    if (t.isComprehensionExpression(block)) {
+    if (path.isComprehensionExpression()) {
-      this.registerBinding("let", block);
+      this.registerBinding("let", path);
     }
 
     // Program, Function - var variables
 
-    if (t.isProgram(block) || t.isFunction(block)) {
+    if (path.isProgram() || path.isFunction()) {
-      this.traverse(block, functionVariableVisitor, {
+      this.traverse(path.node, functionVariableVisitor, {
-        blockId: block.id,
+        blockId: path.get("id").node,
         scope:   this
       });
     }
 
     // Program
 
-    if (t.isProgram(block)) {
+    if (path.isProgram()) {
-      this.traverse(block, programReferenceVisitor, this);
+      this.traverse(path.node, programReferenceVisitor, this);
     }
   }
 
@@ -674,7 +578,7 @@ export default class Scope {
    * Description
    */
 
-  getBindingInfo(name: string) {
+  getBinding(name: string) {
     var scope = this;
 
     do {
@@ -696,7 +600,7 @@ export default class Scope {
    */
 
   getBindingIdentifier(name: string) {
-    var info = this.getBindingInfo(name);
+    var info = this.getBinding(name);
     return info && info.identifier;
   }
 
@@ -722,29 +626,11 @@ export default class Scope {
    */
 
   getImmutableBindingValue(name: string) {
-    return this._immutableBindingInfoToValue(this.getBindingInfo(name));
+    return this._immutableBindingInfoToValue(this.getBinding(name));
   }
 
-  _immutableBindingInfoToValue(info) {
+  _immutableBindingInfoToValue(binding) {
-    if (!info) return;
+    if (binding) return binding.getValueIfImmutable();
-
-    // can't guarantee this value is the same
-    if (info.reassigned) return;
-
-    var node = info.node;
-    if (t.isVariableDeclarator(node)) {
-      if (t.isIdentifier(node.id)) {
-        node = node.init;
-      } else {
-        // otherwise it's probably a destructuring like:
-        // var { foo } = "foo";
-        return;
-      }
-    }
-
-    if (t.isImmutable(node)) {
-      return node;
-    }
   }
 
   /**
@@ -789,7 +675,7 @@ export default class Scope {
    */
 
   removeBinding(name: string) {
-    var info = this.getBindingInfo(name);
+    var info = this.getBinding(name);
     if (info) info.scope.removeOwnBinding(name);
   }
 }

src/babel/types/converters.js

@@ -10,7 +10,7 @@ import * as t from "./index";
  * Description
  */
 
-export function toComputedKey(node: Object, key: Object = node.key): Object {
+export function toComputedKey(node: Object, key: Object = node.key || node.property): Object {
   if (!node.computed) {
     if (t.isIdentifier(key)) key = t.literal(key.name);
   }

src/babel/types/index.js

@@ -281,7 +281,6 @@ export function inheritsComments(child: Object, parent: Object): Object {
 
 export function inherits(child: Object, parent: Object): Object {
   child._declarations = parent._declarations;
-  child._scopeInfo    = parent._scopeInfo;
   child.range         = parent.range;
   child.start         = parent.start;
   child.loc           = parent.loc;