🤖 Pick PR #53385 (Add missing ambient check to `verba...) into release-5.0 (#53389)

Co-authored-by: Andrew Branch <andrew@wheream.io>

Author: TypeScript Bot

src/compiler/checker.ts

@@ -44164,15 +44164,15 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 if (getAllSymbolFlags(sym) & SymbolFlags.Value) {
                     // However if it is a value, we need to check it's being used correctly
                     checkExpressionCached(id);
-                    if (!isIllegalExportDefaultInCJS && compilerOptions.verbatimModuleSyntax && getTypeOnlyAliasDeclaration(sym, SymbolFlags.Value)) {
+                    if (!isIllegalExportDefaultInCJS && !(node.flags & NodeFlags.Ambient) && compilerOptions.verbatimModuleSyntax && getTypeOnlyAliasDeclaration(sym, SymbolFlags.Value)) {
                         error(id,
                             node.isExportEquals
                                 ? Diagnostics.An_export_declaration_must_reference_a_real_value_when_verbatimModuleSyntax_is_enabled_but_0_resolves_to_a_type_only_declaration
                                 : Diagnostics.An_export_default_must_reference_a_real_value_when_verbatimModuleSyntax_is_enabled_but_0_resolves_to_a_type_only_declaration,
                             idText(id));
                     }
                 }
-                else if (!isIllegalExportDefaultInCJS && compilerOptions.verbatimModuleSyntax) {
+                else if (!isIllegalExportDefaultInCJS && !(node.flags & NodeFlags.Ambient) && compilerOptions.verbatimModuleSyntax) {
                     error(id,
                         node.isExportEquals
                             ? Diagnostics.An_export_declaration_must_reference_a_value_when_verbatimModuleSyntax_is_enabled_but_0_only_refers_to_a_type

tests/baselines/reference/verbatimModuleSyntaxDeclarationFile.symbols

@@ -0,0 +1,24 @@
+=== tests/cases/conformance/externalModules/type1.d.ts ===
+declare namespace NS {
+>NS : Symbol(NS, Decl(type1.d.ts, 0, 0))
+
+    type A = object;
+>A : Symbol(A, Decl(type1.d.ts, 0, 22))
+}
+
+export = NS;
+>NS : Symbol(NS, Decl(type1.d.ts, 0, 0))
+
+export as namespace MyTypes;
+>MyTypes : Symbol(MyTypes, Decl(type1.d.ts, 4, 12))
+
+=== tests/cases/conformance/externalModules/type2.d.ts ===
+import type * as NS from './type1';
+>NS : Symbol(NS, Decl(type2.d.ts, 0, 11))
+
+export = NS;
+>NS : Symbol(NS, Decl(type2.d.ts, 0, 11))
+
+export as namespace ModuleATypes;
+>ModuleATypes : Symbol(ModuleATypes, Decl(type2.d.ts, 2, 12))
+

tests/baselines/reference/verbatimModuleSyntaxDeclarationFile.types

@@ -0,0 +1,22 @@
+=== tests/cases/conformance/externalModules/type1.d.ts ===
+declare namespace NS {
+    type A = object;
+>A : object
+}
+
+export = NS;
+>NS : any
+
+export as namespace MyTypes;
+>MyTypes : error
+
+=== tests/cases/conformance/externalModules/type2.d.ts ===
+import type * as NS from './type1';
+>NS : error
+
+export = NS;
+>NS : any
+
+export as namespace ModuleATypes;
+>ModuleATypes : error
+

tests/baselines/reference/verbatimModuleSyntaxNoElisionCJS.errors.txt

@@ -1,7 +1,6 @@
 /a.ts(2,10): error TS1282: An 'export =' declaration must reference a value when 'verbatimModuleSyntax' is enabled, but 'I' only refers to a type.
 /b.ts(1,1): error TS1484: 'I' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
 /d.ts(3,10): error TS1283: An 'export =' declaration must reference a real value when 'verbatimModuleSyntax' is enabled, but 'J' resolves to a type-only declaration.
-/e.d.ts(2,10): error TS1282: An 'export =' declaration must reference a value when 'verbatimModuleSyntax' is enabled, but 'I' only refers to a type.
 
 
 ==== /a.ts (1 errors) ====
@@ -29,11 +28,9 @@
              ~
 !!! error TS1283: An 'export =' declaration must reference a real value when 'verbatimModuleSyntax' is enabled, but 'J' resolves to a type-only declaration.
 
-==== /e.d.ts (1 errors) ====
+==== /e.d.ts (0 errors) ====
     interface I {}
     export = I;
-             ~
-!!! error TS1282: An 'export =' declaration must reference a value when 'verbatimModuleSyntax' is enabled, but 'I' only refers to a type.
 
 ==== /f.ts (0 errors) ====
     import type I = require("./e");

tests/cases/conformance/externalModules/verbatimModuleSyntaxDeclarationFile.ts

@@ -0,0 +1,15 @@
+// @verbatimModuleSyntax: true
+
+// @Filename: type1.d.ts
+declare namespace NS {
+    type A = object;
+}
+
+export = NS;
+export as namespace MyTypes;
+
+// @Filename: type2.d.ts
+import type * as NS from './type1';
+
+export = NS;
+export as namespace ModuleATypes;