Revert namespace

Author: jakebailey

src/compiler/checker.ts

@@ -2734,7 +2734,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
 
         function addDeclarationDiagnostic(id: string, message: DiagnosticMessage) {
             return (declaration: Declaration) => {
-                if (!isTypeDeclaration(declaration) && declaration.kind !== SyntaxKind.ClassDeclaration && declaration.kind !== SyntaxKind.ModuleDeclaration) {
+                if (!isTypeDeclaration(declaration) && declaration.kind !== SyntaxKind.ClassDeclaration) {
                     diagnostics.add(createDiagnosticForNode(declaration, message, id));
                 }
             };
@@ -45641,10 +45641,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             }
         }
 
-        if (node.name.kind === SyntaxKind.Identifier) {
-            checkTypeNameIsReserved(node.name, Diagnostics.Namespace_name_cannot_be_0);
-        }
-
         addLazyDiagnostic(checkModuleDeclarationDiagnostics);
 
         function checkModuleDeclarationDiagnostics() {

tests/baselines/reference/parserModuleDeclaration11.errors.txt

@@ -1,14 +1,10 @@
-typeNamedUndefined2.ts(2,22): error TS2819: Namespace name cannot be 'undefined'.
 typeNamedUndefined2.ts(4,21): error TS2457: Type alias name cannot be 'undefined'.
-typeNamedUndefined2.ts(15,18): error TS2819: Namespace name cannot be 'undefined'.
 typeNamedUndefined2.ts(17,17): error TS2457: Type alias name cannot be 'undefined'.
 
 
-==== typeNamedUndefined2.ts (4 errors) ====
+==== typeNamedUndefined2.ts (2 errors) ====
     export namespace ns {
         export namespace undefined {
-                         ~~~~~~~~~
-!!! error TS2819: Namespace name cannot be 'undefined'.
             export const s = Symbol();
             export type undefined = typeof s;
                         ~~~~~~~~~
@@ -24,8 +20,6 @@ typeNamedUndefined2.ts(17,17): error TS2457: Type alias name cannot be 'undefine
     }
 
     export namespace undefined {
-                     ~~~~~~~~~
-!!! error TS2819: Namespace name cannot be 'undefined'.
         export const s = Symbol();
         export type undefined = typeof s;
                     ~~~~~~~~~

tests/baselines/reference/parserModuleDeclaration12.errors.txt

@@ -1,6 +1,6 @@
 undefinedTypeAssignment4.ts(1,7): error TS2414: Class name cannot be 'undefined'.
 undefinedTypeAssignment4.ts(4,11): error TS2427: Interface name cannot be 'undefined'.
-undefinedTypeAssignment4.ts(7,11): error TS2819: Namespace name cannot be 'undefined'.
+undefinedTypeAssignment4.ts(7,11): error TS2397: Declaration name conflicts with built-in global identifier 'undefined'.
 
 
 ==== undefinedTypeAssignment4.ts (3 errors) ====
@@ -16,7 +16,7 @@ undefinedTypeAssignment4.ts(7,11): error TS2819: Namespace name cannot be 'undef
     }
     namespace undefined {
               ~~~~~~~~~
-!!! error TS2819: Namespace name cannot be 'undefined'.
+!!! error TS2397: Declaration name conflicts with built-in global identifier 'undefined'.
     	export var x = 42;
     }
     var x: undefined;