Fix private properties not being allowed in optional chains

src/compiler/diagnosticMessages.json

@@ -8322,10 +8322,6 @@
         "category": "Error",
         "code": 18029
     },
-    "An optional chain cannot contain private identifiers.": {
-        "category": "Error",
-        "code": 18030
-    },
     "The intersection '{0}' was reduced to 'never' because property '{1}' has conflicting types in some constituents.": {
         "category": "Error",
         "code": 18031

src/compiler/parser.ts

@@ -159,7 +159,6 @@ import {
     isMetaProperty,
     isModifierKind,
     isNonNullExpression,
-    isPrivateIdentifier,
     isSetAccessorDeclaration,
     isStringOrNumericLiteralLike,
     isTaggedTemplateExpression,
@@ -6405,9 +6404,6 @@ namespace Parser {
         const propertyAccess = isOptionalChain ?
             factoryCreatePropertyAccessChain(expression, questionDotToken, name) :
             factoryCreatePropertyAccessExpression(expression, name);
-        if (isOptionalChain && isPrivateIdentifier(propertyAccess.name)) {
-            parseErrorAtRange(propertyAccess.name, Diagnostics.An_optional_chain_cannot_contain_private_identifiers);
-        }
         if (isExpressionWithTypeArguments(expression) && expression.typeArguments) {
             const pos = expression.typeArguments.pos - 1;
             const end = skipTrivia(sourceText, expression.typeArguments.end) + 1;

tests/baselines/reference/privateIdentifierChain.1.js

@@ -8,9 +8,11 @@ class A {
         return new A();
     }
     constructor() {
-        this?.#b;           // Error
-        this?.a.#b;         // Error
-        this?.getA().#b;    // Error
+        this.a = this;
+        // None of these should error
+        this?.#b;
+        this?.a.#b;
+        this?.getA().#b;
     }
 }
 
@@ -23,8 +25,10 @@ class A {
         return new A();
     }
     constructor() {
-        this?.#b; // Error
-        this?.a.#b; // Error
-        this?.getA().#b; // Error
+        this.a = this;
+        // None of these should error
+        this?.#b;
+        this?.a.#b;
+        this?.getA().#b;
     }
 }

tests/baselines/reference/privateIdentifierChain.1.symbols

@@ -20,17 +20,24 @@ class A {
 >A : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))
     }
     constructor() {
-        this?.#b;           // Error
+        this.a = this;
+>this.a : Symbol(A.a, Decl(privateIdentifierChain.1.ts, 0, 9))
+>this : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))
+>a : Symbol(A.a, Decl(privateIdentifierChain.1.ts, 0, 9))
+>this : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))
+
+        // None of these should error
+        this?.#b;
 >this?.#b : Symbol(A.#b, Decl(privateIdentifierChain.1.ts, 1, 9))
 >this : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))
 
-        this?.a.#b;         // Error
+        this?.a.#b;
 >this?.a.#b : Symbol(A.#b, Decl(privateIdentifierChain.1.ts, 1, 9))
 >this?.a : Symbol(A.a, Decl(privateIdentifierChain.1.ts, 0, 9))
 >this : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))
 >a : Symbol(A.a, Decl(privateIdentifierChain.1.ts, 0, 9))
 
-        this?.getA().#b;    // Error
+        this?.getA().#b;
 >this?.getA().#b : Symbol(A.#b, Decl(privateIdentifierChain.1.ts, 1, 9))
 >this?.getA : Symbol(A.getA, Decl(privateIdentifierChain.1.ts, 2, 11))
 >this : Symbol(A, Decl(privateIdentifierChain.1.ts, 0, 0))

tests/baselines/reference/privateIdentifierChain.1.types

@@ -24,23 +24,36 @@ class A {
 >  : ^^^^^^^^
     }
     constructor() {
-        this?.#b;           // Error
+        this.a = this;
+>this.a = this : this
+>              : ^^^^
+>this.a : A | undefined
+>       : ^^^^^^^^^^^^^
+>this : this
+>     : ^^^^
+>a : A | undefined
+>  : ^^^^^^^^^^^^^
+>this : this
+>     : ^^^^
+
+        // None of these should error
+        this?.#b;
 >this?.#b : A | undefined
 >         : ^^^^^^^^^^^^^
 >this : this
 >     : ^^^^
 
-        this?.a.#b;         // Error
+        this?.a.#b;
 >this?.a.#b : A | undefined
 >           : ^^^^^^^^^^^^^
->this?.a : A | undefined
->        : ^^^^^^^^^^^^^
+>this?.a : A
+>        : ^
 >this : this
 >     : ^^^^
->a : A | undefined
->  : ^^^^^^^^^^^^^
+>a : A
+>  : ^
 
-        this?.getA().#b;    // Error
+        this?.getA().#b;
 >this?.getA().#b : A | undefined
 >                : ^^^^^^^^^^^^^
 >this?.getA() : A

tests/baselines/reference/privateNameUncheckedJsOptionalChain.types

@@ -7,18 +7,15 @@ class C {
 
     #bar;
 >#bar : any
->     : ^^^
 
     constructor () {
         this?.#foo;
->this?.#foo : any
->           : ^^^
+>this?.#foo : error
 >this : this
 >     : ^^^^
 
         this?.#bar;
 >this?.#bar : any
->           : ^^^
 >this : this
 >     : ^^^^
     }

tests/cases/conformance/expressions/optionalChaining/privateIdentifierChain/privateIdentifierChain.1.ts

@@ -9,8 +9,10 @@ class A {
         return new A();
     }
     constructor() {
-        this?.#b;           // Error
-        this?.a.#b;         // Error
-        this?.getA().#b;    // Error
+        this.a = this;
+        // None of these should error
+        this?.#b;
+        this?.a.#b;
+        this?.getA().#b;
     }
 }