Consistent const violations (#6100)

* Changed updateExpression to report itself as violation instead of its argument

* Update getBindingIdentifiers to work with forXStatement and return proper node as violation

* Updated unaryExpression violation to be consistent with changes.

packages/babel-plugin-check-es2015-constants/src/index.js

@@ -36,13 +36,13 @@ export default function({ messages, types: t }) {
                     violation.get("right").node,
                   ),
                 );
-            } else if (violation.parentPath.isUpdateExpression()) {
-              violation.parentPath.replaceWith(
-                statementBeforeExpression(throwNode, violation.parent),
+            } else if (violation.isUpdateExpression()) {
+              violation.replaceWith(
+                statementBeforeExpression(throwNode, violation.node),
               );
-            } else if (violation.parentPath.isForXStatement()) {
-              violation.parentPath.ensureBlock();
-              violation.parentPath.node.body.body.unshift(throwNode);
+            } else if (violation.isForXStatement()) {
+              violation.ensureBlock();
+              violation.node.body.body.unshift(throwNode);
             }
           }
         }

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

@@ -104,7 +104,7 @@ const collectorVisitor = {
   ForXStatement(path, state) {
     const left = path.get("left");
     if (left.isPattern() || left.isIdentifier()) {
-      state.constantViolations.push(left);
+      state.constantViolations.push(path);
     }
   },
 
@@ -140,12 +140,12 @@ const collectorVisitor = {
   },
 
   UpdateExpression(path, state) {
-    state.constantViolations.push(path.get("argument"));
+    state.constantViolations.push(path);
   },
 
   UnaryExpression(path, state) {
     if (path.node.operator === "delete") {
-      state.constantViolations.push(path.get("argument"));
+      state.constantViolations.push(path);
     }
   },
 

packages/babel-types/src/retrievers.js

@@ -89,6 +89,9 @@ getBindingIdentifiers.keys = {
   FunctionDeclaration: ["id", "params"],
   FunctionExpression: ["id", "params"],
 
+  ForInStatement: ["left"],
+  ForOfStatement: ["left"],
+
   ClassDeclaration: ["id"],
   ClassExpression: ["id"],