Add diagnostic for private identifiers in destructuring patterns

tsc/internal/checker/checker.go

@@ -5902,6 +5902,11 @@ func (c *Checker) checkVariableLikeDeclaration(node *ast.Node) {
 	}
 	if ast.IsBindingElement(node) {
 		propName := node.PropertyName()
+
+		if propName != nil && ast.IsPrivateIdentifier(propName) {
+			c.grammarErrorOnNode(propName, diagnostics.Private_identifiers_cannot_be_used_in_destructuring_patterns)
+		}
+
 		if propName != nil && ast.IsIdentifier(node.Name()) && ast.IsPartOfParameterDeclaration(node) && ast.NodeIsMissing(ast.GetContainingFunction(node).Body()) {
 			// type F = ({a: string}) => void;
 			//               ^^^^^^
@@ -12693,6 +12698,11 @@ func (c *Checker) checkObjectLiteralDestructuringPropertyAssignment(node *ast.No
 	property := properties[propertyIndex]
 	if ast.IsPropertyAssignment(property) || ast.IsShorthandPropertyAssignment(property) {
 		name := property.Name()
+
+		if name != nil && ast.IsPrivateIdentifier(name) {
+			c.grammarErrorOnNode(name, diagnostics.Private_identifiers_cannot_be_used_in_destructuring_patterns)
+		}
+
 		exprType := c.getLiteralTypeFromPropertyName(name)
 		if isTypeUsableAsPropertyName(exprType) {
 			text := getPropertyNameFromType(exprType)

tsc/internal/diagnostics/diagnosticMessages.json

@@ -8555,5 +8555,9 @@
     "'{0}' is not a valid meta-property for keyword 'import'. Did you mean 'meta' or 'defer'?": {
         "category": "Error",
         "code": 18061
+    },
+    "Private identifiers cannot be used in destructuring patterns.": {
+        "category": "Error",
+        "code": 18064
     }
 }

tsc/testdata/baselines/reference/conformance/privateNamesNotAllowedAsDestructuringPatterns.errors.txt

@@ -0,0 +1,18 @@
+privateNamesNotAllowedAsDestructuringPatterns.ts(4,17): error TS18064: Private identifiers cannot be used in destructuring patterns.
+privateNamesNotAllowedAsDestructuringPatterns.ts(6,12): error TS18064: Private identifiers cannot be used in destructuring patterns.
+
+
+==== privateNamesNotAllowedAsDestructuringPatterns.ts (2 errors) ====
+    class A {
+        #foo = 1;
+        bar() {
+            const { #foo: foo } = this;
+                    ~~~~
+!!! error TS18064: Private identifiers cannot be used in destructuring patterns.
+            let bar;
+            ({ #foo: bar } = this);
+               ~~~~
+!!! error TS18064: Private identifiers cannot be used in destructuring patterns.
+        }
+    }
+

tsc/testdata/baselines/reference/conformance/privateNamesNotAllowedAsDestructuringPatterns.js

@@ -0,0 +1,23 @@
+//// [tests/cases/conformance/classes/members/privateNames/privateNamesNotAllowedAsDestructuringPatterns.ts] ////
+
+//// [privateNamesNotAllowedAsDestructuringPatterns.ts]
+class A {
+    #foo = 1;
+    bar() {
+        const { #foo: foo } = this;
+        let bar;
+        ({ #foo: bar } = this);
+    }
+}
+
+
+//// [privateNamesNotAllowedAsDestructuringPatterns.js]
+"use strict";
+class A {
+    #foo = 1;
+    bar() {
+        const { #foo: foo } = this;
+        let bar;
+        ({ #foo: bar } = this);
+    }
+}

tsc/testdata/baselines/reference/conformance/privateNamesNotAllowedAsDestructuringPatterns.symbols

@@ -0,0 +1,26 @@
+//// [tests/cases/conformance/classes/members/privateNames/privateNamesNotAllowedAsDestructuringPatterns.ts] ////
+
+=== privateNamesNotAllowedAsDestructuringPatterns.ts ===
+class A {
+>A : Symbol(A, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 0, 0))
+
+    #foo = 1;
+>#foo : Symbol(A.#foo, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 0, 9))
+
+    bar() {
+>bar : Symbol(A.bar, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 1, 13))
+
+        const { #foo: foo } = this;
+>foo : Symbol(foo, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 3, 15))
+>this : Symbol(A, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 0, 0))
+
+        let bar;
+>bar : Symbol(bar, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 4, 11))
+
+        ({ #foo: bar } = this);
+>#foo : Symbol(#foo, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 5, 10))
+>bar : Symbol(bar, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 4, 11))
+>this : Symbol(A, Decl(privateNamesNotAllowedAsDestructuringPatterns.ts, 0, 0))
+    }
+}
+

tsc/testdata/baselines/reference/conformance/privateNamesNotAllowedAsDestructuringPatterns.types

@@ -0,0 +1,30 @@
+//// [tests/cases/conformance/classes/members/privateNames/privateNamesNotAllowedAsDestructuringPatterns.ts] ////
+
+=== privateNamesNotAllowedAsDestructuringPatterns.ts ===
+class A {
+>A : A
+
+    #foo = 1;
+>#foo : number
+>1 : 1
+
+    bar() {
+>bar : () => void
+
+        const { #foo: foo } = this;
+>foo : never
+>this : this
+
+        let bar;
+>bar : any
+
+        ({ #foo: bar } = this);
+>({ #foo: bar } = this) : this
+>{ #foo: bar } = this : this
+>{ #foo: bar } : { #foo: any; }
+>#foo : any
+>bar : any
+>this : this
+    }
+}
+

tsc/testdata/tests/cases/conformance/classes/members/privateNames/privateNamesNotAllowedAsDestructuringPatterns.ts

@@ -0,0 +1,10 @@
+// @target: es2022
+
+class A {
+    #foo = 1;
+    bar() {
+        const { #foo: foo } = this;
+        let bar;
+        ({ #foo: bar } = this);
+    }
+}