Introduce scope tracking in the parser (#9493)

* Introduce scope tracking

* Fix tests

* Add new tests

* Remove constructor-super check from transform as it is now in parser

* Correctly handle class properties and class scope

* Fix duplicate name check

* Convert scope identifier storage to array

* Enter a new scope in typescript module blocks

* Add test for duplicate declaration

* Rename error for duplicate exports

* Treat class declarations as lexical declaration

* Update whitelist

* Add tests

* Fix scope tracking for function declarations

* Migrate try-catch duplicate error

* Fix test

* More tests

* One more test

* Make scope a separate class and fix review comments

* Do not allow new.target in top scope arrow function

* Correctly enter new scope for declare module and treat type aliases as lexical declarations

* Tests for typescript scope tracking to not mark type aliases as duplicate

* Fix flow scope tracking

* Remove ident from test names as redundant

* Add test case for var and function

* Improve error messages

* Improve literal regex

packages/babel-parser/src/parser/lval.js

@@ -16,6 +16,7 @@ import type {
 import type { Pos, Position } from "../util/location";
 import { isStrictBindReservedWord } from "../util/identifier";
 import { NodeUtils } from "./node";
+import { type BindingTypes, BIND_NONE, BIND_OUTSIDE } from "../util/scopeflags";
 
 export default class LValParser extends NodeUtils {
   // Forward-declaration: defined in expression.js
@@ -262,7 +263,7 @@ export default class LValParser extends NodeUtils {
         elts.push(this.parseAssignableListItemTypes(this.parseRest()));
         this.checkCommaAfterRest(
           close,
-          this.state.inFunction && this.state.inParameters
+          this.scope.inFunction && this.state.inParameters
             ? "parameter"
             : "element",
         );
@@ -325,7 +326,7 @@ export default class LValParser extends NodeUtils {
 
   checkLVal(
     expr: Expression,
-    isBinding: ?boolean,
+    bindingType: ?BindingTypes = BIND_NONE,
     checkClashes: ?{ [key: string]: boolean },
     contextDescription: string,
   ): void {
@@ -337,7 +338,7 @@ export default class LValParser extends NodeUtils {
         ) {
           this.raise(
             expr.start,
-            `${isBinding ? "Binding" : "Assigning to"} '${
+            `${bindingType === BIND_NONE ? "Assigning to" : "Binding"} '${
               expr.name
             }' in strict mode`,
           );
@@ -358,15 +359,20 @@ export default class LValParser extends NodeUtils {
           const key = `_${expr.name}`;
 
           if (checkClashes[key]) {
-            this.raise(expr.start, "Argument name clash in strict mode");
+            this.raise(expr.start, "Argument name clash");
           } else {
             checkClashes[key] = true;
           }
         }
+        if (bindingType !== BIND_NONE && bindingType !== BIND_OUTSIDE) {
+          this.scope.declareName(expr.name, bindingType, expr.start);
+        }
         break;
 
       case "MemberExpression":
-        if (isBinding) this.raise(expr.start, "Binding member expression");
+        if (bindingType !== BIND_NONE) {
+          this.raise(expr.start, "Binding member expression");
+        }
         break;
 
       case "ObjectPattern":
@@ -374,7 +380,7 @@ export default class LValParser extends NodeUtils {
           if (prop.type === "ObjectProperty") prop = prop.value;
           this.checkLVal(
             prop,
-            isBinding,
+            bindingType,
             checkClashes,
             "object destructuring pattern",
           );
@@ -386,7 +392,7 @@ export default class LValParser extends NodeUtils {
           if (elem) {
             this.checkLVal(
               elem,
-              isBinding,
+              bindingType,
               checkClashes,
               "array destructuring pattern",
             );
@@ -397,21 +403,26 @@ export default class LValParser extends NodeUtils {
       case "AssignmentPattern":
         this.checkLVal(
           expr.left,
-          isBinding,
+          bindingType,
           checkClashes,
           "assignment pattern",
         );
         break;
 
       case "RestElement":
-        this.checkLVal(expr.argument, isBinding, checkClashes, "rest element");
+        this.checkLVal(
+          expr.argument,
+          bindingType,
+          checkClashes,
+          "rest element",
+        );
         break;
 
       default: {
         const message =
-          (isBinding
-            ? /* istanbul ignore next */ "Binding invalid"
-            : "Invalid") +
+          (bindingType === BIND_NONE
+            ? "Invalid"
+            : /* istanbul ignore next */ "Binding invalid") +
           " left-hand side" +
           (contextDescription
             ? " in " + contextDescription