Transform namespaces declared with module keyword to namespace keyword in d.ts files

src/compiler/factory/nodeFactory.ts

@@ -146,6 +146,7 @@ import {
     InterfaceDeclaration,
     InternalEmitFlags,
     IntersectionTypeNode,
+    isAmbientModule,
     isArray,
     isArrayLiteralExpression,
     isArrowFunction,
@@ -765,6 +766,7 @@ export function createNodeFactory(flags: NodeFactoryFlags, baseFactory: BaseNode
         updateEnumDeclaration,
         createModuleDeclaration,
         updateModuleDeclaration,
+        updateModuleDeclarationAndKeyword,
         createModuleBlock,
         updateModuleBlock,
         createCaseBlock,
@@ -4476,6 +4478,20 @@ export function createNodeFactory(flags: NodeFactoryFlags, baseFactory: BaseNode
             : node;
     }
 
+    // @api
+    function updateModuleDeclarationAndKeyword(
+        node: ModuleDeclaration,
+        modifiers: readonly ModifierLike[] | undefined,
+        name: ModuleName,
+        body: ModuleBody | undefined
+    ) {
+        if (isAmbientModule(node)) {
+            return updateModuleDeclaration(node, modifiers, name, body);
+        }
+
+        return update(createModuleDeclaration(modifiers, name, body, node.flags | NodeFlags.Namespace), node);
+    }
+
     // @api
     function createModuleBlock(statements: readonly Statement[]) {
         const node = createBaseNode<ModuleBlock>(SyntaxKind.ModuleBlock);

src/compiler/transformers/declarations.ts

@@ -1595,7 +1595,7 @@ export function transformDeclarations(context: TransformationContext) {
                     needsScopeFixMarker = oldNeedsScopeFix;
                     resultHasScopeMarker = oldHasScopeFix;
                     const mods = ensureModifiers(input);
-                    return cleanup(factory.updateModuleDeclaration(
+                    return cleanup(factory.updateModuleDeclarationAndKeyword(
                         input,
                         mods,
                         isExternalModuleAugmentation(input) ? rewriteModuleSpecifier(input, input.name) : input.name,
@@ -1611,7 +1611,7 @@ export function transformDeclarations(context: TransformationContext) {
                     const id = getOriginalNodeId(inner!); // TODO: GH#18217
                     const body = lateStatementReplacementMap.get(id);
                     lateStatementReplacementMap.delete(id);
-                    return cleanup(factory.updateModuleDeclaration(
+                    return cleanup(factory.updateModuleDeclarationAndKeyword(
                         input,
                         mods,
                         input.name,

src/compiler/types.ts

@@ -8587,6 +8587,7 @@ export interface NodeFactory {
     updateEnumDeclaration(node: EnumDeclaration, modifiers: readonly ModifierLike[] | undefined, name: Identifier, members: readonly EnumMember[]): EnumDeclaration;
     createModuleDeclaration(modifiers: readonly ModifierLike[] | undefined, name: ModuleName, body: ModuleBody | undefined, flags?: NodeFlags): ModuleDeclaration;
     updateModuleDeclaration(node: ModuleDeclaration, modifiers: readonly ModifierLike[] | undefined, name: ModuleName, body: ModuleBody | undefined): ModuleDeclaration;
+    /** @internal */ updateModuleDeclarationAndKeyword(node: ModuleDeclaration, modifiers: readonly ModifierLike[] | undefined, name: ModuleName, body: ModuleBody | undefined): ModuleDeclaration;
     createModuleBlock(statements: readonly Statement[]): ModuleBlock;
     updateModuleBlock(node: ModuleBlock, statements: readonly Statement[]): ModuleBlock;
     createCaseBlock(clauses: readonly CaseOrDefaultClause[]): CaseBlock;

tests/baselines/reference/aliasInaccessibleModule.js

@@ -12,8 +12,8 @@ var M;
 
 
 //// [aliasInaccessibleModule.d.ts]
-declare module M {
-    module N {
+declare namespace M {
+    namespace N {
     }
     export import X = N;
     export {};

tests/baselines/reference/aliasInaccessibleModule2.js

@@ -26,8 +26,8 @@ var M;
 
 
 //// [aliasInaccessibleModule2.d.ts]
-declare module M {
-    module N {
+declare namespace M {
+    namespace N {
     }
     import R = N;
     export import X = R;

tests/baselines/reference/classConstructorAccessibility.js

@@ -98,5 +98,5 @@ declare class E {
 declare var c: C;
 declare var d: any;
 declare var e: any;
-declare module Generic {
+declare namespace Generic {
 }

tests/baselines/reference/classDoesNotDependOnPrivateMember.js

@@ -19,7 +19,7 @@ var M;
 
 
 //// [classDoesNotDependOnPrivateMember.d.ts]
-declare module M {
+declare namespace M {
     class C {
         private x;
     }

tests/baselines/reference/classdecl.js

@@ -233,14 +233,14 @@ declare class a {
 }
 declare class b extends a {
 }
-declare module m1 {
+declare namespace m1 {
     class b {
     }
     interface ib {
     }
 }
-declare module m2 {
-    module m3 {
+declare namespace m2 {
+    namespace m3 {
         class c extends b {
         }
         class ib2 implements m1.ib {

tests/baselines/reference/commentsDottedModuleName.js

@@ -30,7 +30,7 @@ define(["require", "exports"], function (require, exports) {
 
 //// [commentsDottedModuleName.d.ts]
 /** this is multi declare module*/
-export declare module outerModule.InnerModule {
+export declare namespace outerModule.InnerModule {
     class b {
     }
 }

tests/baselines/reference/commentsExternalModules.js

@@ -139,11 +139,11 @@ define(["require", "exports", "commentsExternalModules_0"], function (require, e
 
 //// [commentsExternalModules_0.d.ts]
 /** Module comment*/
-export declare module m1 {
+export declare namespace m1 {
     /** b's comment*/
     var b: number;
     /** m2 comments*/
-    module m2 {
+    namespace m2 {
         /** class comment;*/
         class c {
         }
@@ -154,12 +154,12 @@ export declare module m1 {
     function fooExport(): number;
 }
 /** Module comment */
-export declare module m4 {
+export declare namespace m4 {
     /** b's comment */
     var b: number;
     /** m2 comments
     */
-    module m2 {
+    namespace m2 {
         /** class comment; */
         class c {
         }

tests/baselines/reference/commentsExternalModules2.js

@@ -140,11 +140,11 @@ define(["require", "exports", "commentsExternalModules2_0"], function (require,
 
 //// [commentsExternalModules2_0.d.ts]
 /** Module comment*/
-export declare module m1 {
+export declare namespace m1 {
     /** b's comment*/
     var b: number;
     /** m2 comments*/
-    module m2 {
+    namespace m2 {
         /** class comment;*/
         class c {
         }
@@ -155,12 +155,12 @@ export declare module m1 {
     function fooExport(): number;
 }
 /** Module comment */
-export declare module m4 {
+export declare namespace m4 {
     /** b's comment */
     var b: number;
     /** m2 comments
     */
-    module m2 {
+    namespace m2 {
         /** class comment; */
         class c {
         }

tests/baselines/reference/commentsExternalModules3.js

@@ -138,11 +138,11 @@ exports.newVar2 = new extMod.m4.m2.c();
 
 //// [commentsExternalModules2_0.d.ts]
 /** Module comment*/
-export declare module m1 {
+export declare namespace m1 {
     /** b's comment*/
     var b: number;
     /** m2 comments*/
-    module m2 {
+    namespace m2 {
         /** class comment;*/
         class c {
         }
@@ -153,12 +153,12 @@ export declare module m1 {
     function fooExport(): number;
 }
 /** Module comment */
-export declare module m4 {
+export declare namespace m4 {
     /** b's comment */
     var b: number;
     /** m2 comments
     */
-    module m2 {
+    namespace m2 {
         /** class comment; */
         class c {
         }

tests/baselines/reference/commentsFormatting.js

@@ -188,7 +188,7 @@ this is 4 spaces left aligned but above line is empty
 
 
 //// [commentsFormatting.d.ts]
-declare module m {
+declare namespace m {
     /** this is first line - aligned to class declaration
 * this is 4 spaces left aligned
  * this is 3 spaces left aligned

tests/baselines/reference/commentsModules.js

@@ -270,11 +270,11 @@ new m7.m8.m9.c();
 
 //// [commentsModules.d.ts]
 /** Module comment*/
-declare module m1 {
+declare namespace m1 {
     /** b's comment*/
     var b: number;
     /** m2 comments*/
-    module m2 {
+    namespace m2 {
         /** class comment;*/
         class c {
         }
@@ -291,44 +291,44 @@ declare module m1 {
 }
 declare var myvar: m1.m2.c;
 /** module comment of m2.m3*/
-declare module m2.m3 {
+declare namespace m2.m3 {
     /** Exported class comment*/
     class c {
     }
 }
 /** module comment of m3.m4.m5*/
-declare module m3.m4.m5 {
+declare namespace m3.m4.m5 {
     /** Exported class comment*/
     class c {
     }
 }
 /** module comment of m4.m5.m6*/
-declare module m4.m5.m6 {
-    module m7 {
+declare namespace m4.m5.m6 {
+    namespace m7 {
         /** Exported class comment*/
         class c {
         }
     }
 }
 /** module comment of m5.m6.m7*/
-declare module m5.m6.m7 {
+declare namespace m5.m6.m7 {
     /** module m8 comment*/
-    module m8 {
+    namespace m8 {
         /** Exported class comment*/
         class c {
         }
     }
 }
-declare module m6.m7 {
-    module m8 {
+declare namespace m6.m7 {
+    namespace m8 {
         /** Exported class comment*/
         class c {
         }
     }
 }
-declare module m7.m8 {
+declare namespace m7.m8 {
     /** module m9 comment*/
-    module m9 {
+    namespace m9 {
         /** Exported class comment*/
         class c {
         }

tests/baselines/reference/commentsMultiModuleMultiFile.js

@@ -100,12 +100,12 @@ define(["require", "exports"], function (require, exports) {
 
 //// [commentsMultiModuleMultiFile_0.d.ts]
 /** this is multi declare module*/
-export declare module multiM {
+export declare namespace multiM {
     class b {
     }
 }
 /** thi is multi module 2*/
-export declare module multiM {
+export declare namespace multiM {
     /** class c comment*/
     class c {
     }
@@ -114,7 +114,7 @@ export declare module multiM {
 }
 //// [commentsMultiModuleMultiFile_1.d.ts]
 /** this is multi module 3 comment*/
-export declare module multiM {
+export declare namespace multiM {
     /** class d comment*/
     class d {
     }

tests/baselines/reference/commentsMultiModuleSingleFile.js

@@ -65,14 +65,14 @@ new multiM.c();
 
 //// [commentsMultiModuleSingleFile.d.ts]
 /** this is multi declare module*/
-declare module multiM {
+declare namespace multiM {
     /** class b*/
     class b {
     }
     class d {
     }
 }
-declare module multiM {
+declare namespace multiM {
     /** class c comment*/
     class c {
     }

tests/baselines/reference/commentsdoNotEmitComments.js

@@ -158,12 +158,12 @@ interface i1 {
     prop: string;
 }
 declare var i1_i: i1;
-declare module m1 {
+declare namespace m1 {
     class b {
         x: number;
         constructor(x: number);
     }
-    module m2 {
+    namespace m2 {
     }
 }
 declare var x: any;

tests/baselines/reference/commentsemitComments.js

@@ -186,13 +186,13 @@ interface i1 {
 /**interface instance comments*/
 declare var i1_i: i1;
 /** this is module comment*/
-declare module m1 {
+declare namespace m1 {
     /** class b */
     class b {
         x: number;
         constructor(x: number);
     }
-    module m2 {
+    namespace m2 {
     }
 }
 declare var x: any;

tests/baselines/reference/constDeclarations2.js

@@ -18,7 +18,7 @@ var M;
 
 
 //// [constDeclarations2.d.ts]
-declare module M {
+declare namespace M {
     const c1 = false;
     const c2: number;
     const c3 = 0, c4: string, c5: any;

tests/baselines/reference/declFileAliasUseBeforeDeclaration2.js

@@ -14,7 +14,7 @@ declare module "test" {
 
 //// [declFileAliasUseBeforeDeclaration2.d.ts]
 declare module "test" {
-    module A {
+    namespace A {
         class C {
         }
     }

tests/baselines/reference/declFileAmbientExternalModuleWithSingleExportedModule.js

@@ -26,8 +26,8 @@ exports.x = void 0;
 
 //// [declFileAmbientExternalModuleWithSingleExportedModule_0.d.ts]
 declare module "SubModule" {
-    module m {
-        module m3 {
+    namespace m {
+        namespace m3 {
             interface c {
             }
         }