Filter #private static members from js declaration emit

src/compiler/checker.ts

@@ -1133,6 +1133,7 @@ import {
     WithStatement,
     WriterContextOut,
     YieldExpression,
+    isPrivateIdentifierSymbol,
 } from "./_namespaces/ts.js";
 import * as moduleSpecifiers from "./_namespaces/ts.moduleSpecifiers.js";
 import * as performance from "./_namespaces/ts.performance.js";
@@ -9770,7 +9771,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 const publicProperties = flatMap<Symbol, ClassElement>(publicSymbolProps, p => serializePropertySymbolForClass(p, /*isStatic*/ false, baseTypes[0]));
                 // Consider static members empty if symbol also has function or module meaning - function namespacey emit will handle statics
                 const staticMembers = flatMap(
-                    filter(getPropertiesOfType(staticType), p => !(p.flags & SymbolFlags.Prototype) && p.escapedName !== "prototype" && !isNamespaceMember(p)),
+                    filter(getPropertiesOfType(staticType), p => !(p.flags & SymbolFlags.Prototype) && p.escapedName !== "prototype" && !isNamespaceMember(p) && !isPrivateIdentifierSymbol(p)),
                     p => serializePropertySymbolForClass(p, /*isStatic*/ true, staticBaseType),
                 );
                 // When we encounter an `X.prototype.y` assignment in a JS file, we bind `X` as a class regardless as to whether

tests/baselines/reference/declarationEmitJsPrivateClassStatics.js

@@ -0,0 +1,20 @@
+//// [tests/cases/compiler/declarationEmitJsPrivateClassStatics.ts] ////
+
+//// [input.js]
+class Test {
+    static #privateStaticProp = 'Not removed for JS declaration generation; is removed for TS.';
+
+    static #privateStaticFn() { return 'Not removed for JS declaration generation; is removed for TS.'; }
+
+    #privateProp = 'This is removed in JS / TS declaration generation.';
+
+    #privateFn() { return 'This is removed in JS / TS declaration generation.'; }
+}
+
+
+
+
+//// [input.d.ts]
+declare class Test {
+    #private;
+}

tests/baselines/reference/declarationEmitJsPrivateClassStatics.symbols

@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/declarationEmitJsPrivateClassStatics.ts] ////
+
+=== input.js ===
+class Test {
+>Test : Symbol(Test, Decl(input.js, 0, 0))
+
+    static #privateStaticProp = 'Not removed for JS declaration generation; is removed for TS.';
+>#privateStaticProp : Symbol(Test.#privateStaticProp, Decl(input.js, 0, 12))
+
+    static #privateStaticFn() { return 'Not removed for JS declaration generation; is removed for TS.'; }
+>#privateStaticFn : Symbol(Test.#privateStaticFn, Decl(input.js, 1, 96))
+
+    #privateProp = 'This is removed in JS / TS declaration generation.';
+>#privateProp : Symbol(Test.#privateProp, Decl(input.js, 3, 105))
+
+    #privateFn() { return 'This is removed in JS / TS declaration generation.'; }
+>#privateFn : Symbol(Test.#privateFn, Decl(input.js, 5, 72))
+}
+

tests/baselines/reference/declarationEmitJsPrivateClassStatics.types

@@ -0,0 +1,32 @@
+//// [tests/cases/compiler/declarationEmitJsPrivateClassStatics.ts] ////
+
+=== input.js ===
+class Test {
+>Test : Test
+>     : ^^^^
+
+    static #privateStaticProp = 'Not removed for JS declaration generation; is removed for TS.';
+>#privateStaticProp : string
+>                   : ^^^^^^
+>'Not removed for JS declaration generation; is removed for TS.' : "Not removed for JS declaration generation; is removed for TS."
+>                                                                : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+    static #privateStaticFn() { return 'Not removed for JS declaration generation; is removed for TS.'; }
+>#privateStaticFn : () => string
+>                 : ^^^^^^^^^^^^
+>'Not removed for JS declaration generation; is removed for TS.' : "Not removed for JS declaration generation; is removed for TS."
+>                                                                : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+    #privateProp = 'This is removed in JS / TS declaration generation.';
+>#privateProp : string
+>             : ^^^^^^
+>'This is removed in JS / TS declaration generation.' : "This is removed in JS / TS declaration generation."
+>                                                     : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+    #privateFn() { return 'This is removed in JS / TS declaration generation.'; }
+>#privateFn : () => string
+>           : ^^^^^^^^^^^^
+>'This is removed in JS / TS declaration generation.' : "This is removed in JS / TS declaration generation."
+>                                                     : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+}
+

tests/cases/compiler/declarationEmitJsPrivateClassStatics.ts

@@ -0,0 +1,14 @@
+// @allowJs: true
+// @emitDeclarationOnly: true
+// @declaration: true
+// @target: es2015
+// @filename: input.js
+class Test {
+    static #privateStaticProp = 'Not removed for JS declaration generation; is removed for TS.';
+
+    static #privateStaticFn() { return 'Not removed for JS declaration generation; is removed for TS.'; }
+
+    #privateProp = 'This is removed in JS / TS declaration generation.';
+
+    #privateFn() { return 'This is removed in JS / TS declaration generation.'; }
+}