fix(48487): allow using private names as the self-assignment entity name

src/compiler/utilities.ts

@@ -2338,18 +2338,13 @@ namespace ts {
         if (isPropertyNameLiteral(name) && isPropertyNameLiteral(initializer)) {
             return getTextOfIdentifierOrLiteral(name) === getTextOfIdentifierOrLiteral(initializer);
         }
-        if (isIdentifier(name) && isLiteralLikeAccess(initializer) &&
+        if (isMemberName(name) && isLiteralLikeAccess(initializer) &&
             (initializer.expression.kind === SyntaxKind.ThisKeyword ||
                 isIdentifier(initializer.expression) &&
                 (initializer.expression.escapedText === "window" ||
                     initializer.expression.escapedText === "self" ||
                     initializer.expression.escapedText === "global"))) {
-
-            const nameOrArgument = getNameOrArgument(initializer);
-            if (isPrivateIdentifier(nameOrArgument)) {
-                Debug.fail("Unexpected PrivateIdentifier in name expression with literal-like access.");
-            }
-            return isSameEntityName(name, nameOrArgument);
+            return isSameEntityName(name, getNameOrArgument(initializer));
         }
         if (isLiteralLikeAccess(name) && isLiteralLikeAccess(initializer)) {
             return getElementOrPropertyAccessName(name) === getElementOrPropertyAccessName(initializer)

tests/baselines/reference/typeFromPrivatePropertyAssignment.js

@@ -0,0 +1,23 @@
+//// [typeFromPrivatePropertyAssignment.ts]
+type Foo = { foo?: string };
+
+class C {
+    #a?: Foo;
+    #b?: Foo;
+
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}
+
+
+//// [typeFromPrivatePropertyAssignment.js]
+class C {
+    #a;
+    #b;
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}

tests/baselines/reference/typeFromPrivatePropertyAssignment.symbols

@@ -0,0 +1,32 @@
+=== tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignment.ts ===
+type Foo = { foo?: string };
+>Foo : Symbol(Foo, Decl(typeFromPrivatePropertyAssignment.ts, 0, 0))
+>foo : Symbol(foo, Decl(typeFromPrivatePropertyAssignment.ts, 0, 12))
+
+class C {
+>C : Symbol(C, Decl(typeFromPrivatePropertyAssignment.ts, 0, 28))
+
+    #a?: Foo;
+>#a : Symbol(C.#a, Decl(typeFromPrivatePropertyAssignment.ts, 2, 9))
+>Foo : Symbol(Foo, Decl(typeFromPrivatePropertyAssignment.ts, 0, 0))
+
+    #b?: Foo;
+>#b : Symbol(C.#b, Decl(typeFromPrivatePropertyAssignment.ts, 3, 13))
+>Foo : Symbol(Foo, Decl(typeFromPrivatePropertyAssignment.ts, 0, 0))
+
+    m() {
+>m : Symbol(C.m, Decl(typeFromPrivatePropertyAssignment.ts, 4, 13))
+
+        const a = this.#a || {};
+>a : Symbol(a, Decl(typeFromPrivatePropertyAssignment.ts, 7, 13))
+>this.#a : Symbol(C.#a, Decl(typeFromPrivatePropertyAssignment.ts, 2, 9))
+>this : Symbol(C, Decl(typeFromPrivatePropertyAssignment.ts, 0, 28))
+
+        this.#b = this.#b || {};
+>this.#b : Symbol(C.#b, Decl(typeFromPrivatePropertyAssignment.ts, 3, 13))
+>this : Symbol(C, Decl(typeFromPrivatePropertyAssignment.ts, 0, 28))
+>this.#b : Symbol(C.#b, Decl(typeFromPrivatePropertyAssignment.ts, 3, 13))
+>this : Symbol(C, Decl(typeFromPrivatePropertyAssignment.ts, 0, 28))
+    }
+}
+

tests/baselines/reference/typeFromPrivatePropertyAssignment.types

@@ -0,0 +1,35 @@
+=== tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignment.ts ===
+type Foo = { foo?: string };
+>Foo : Foo
+>foo : string
+
+class C {
+>C : C
+
+    #a?: Foo;
+>#a : Foo
+
+    #b?: Foo;
+>#b : Foo
+
+    m() {
+>m : () => void
+
+        const a = this.#a || {};
+>a : Foo
+>this.#a || {} : Foo
+>this.#a : Foo
+>this : this
+>{} : {}
+
+        this.#b = this.#b || {};
+>this.#b = this.#b || {} : Foo
+>this.#b : Foo
+>this : this
+>this.#b || {} : Foo
+>this.#b : Foo
+>this : this
+>{} : {}
+    }
+}
+

tests/baselines/reference/typeFromPrivatePropertyAssignmentJs.js

@@ -0,0 +1,29 @@
+//// [tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignmentJs.ts] ////
+
+//// [typeFromPrivatePropertyAssignmentJs.js]
+
+//// [a.js]
+class C {
+    /** @type {{ foo?: string } | undefined } */
+    #a;
+    /** @type {{ foo?: string } | undefined } */
+    #b;
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}
+
+
+//// [typeFromPrivatePropertyAssignmentJs.js]
+//// [a.js]
+class C {
+    /** @type {{ foo?: string } | undefined } */
+    #a;
+    /** @type {{ foo?: string } | undefined } */
+    #b;
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}

tests/baselines/reference/typeFromPrivatePropertyAssignmentJs.symbols

@@ -0,0 +1,30 @@
+=== tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignmentJs.js ===
+
+No type information for this code.=== tests/cases/conformance/classes/members/privateNames/a.js ===
+class C {
+>C : Symbol(C, Decl(a.js, 0, 0))
+
+    /** @type {{ foo?: string } | undefined } */
+    #a;
+>#a : Symbol(C.#a, Decl(a.js, 0, 9))
+
+    /** @type {{ foo?: string } | undefined } */
+    #b;
+>#b : Symbol(C.#b, Decl(a.js, 2, 7))
+
+    m() {
+>m : Symbol(C.m, Decl(a.js, 4, 7))
+
+        const a = this.#a || {};
+>a : Symbol(a, Decl(a.js, 6, 13))
+>this.#a : Symbol(C.#a, Decl(a.js, 0, 9))
+>this : Symbol(C, Decl(a.js, 0, 0))
+
+        this.#b = this.#b || {};
+>this.#b : Symbol(C.#b, Decl(a.js, 2, 7))
+>this : Symbol(C, Decl(a.js, 0, 0))
+>this.#b : Symbol(C.#b, Decl(a.js, 2, 7))
+>this : Symbol(C, Decl(a.js, 0, 0))
+    }
+}
+

tests/baselines/reference/typeFromPrivatePropertyAssignmentJs.types

@@ -0,0 +1,35 @@
+=== tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignmentJs.js ===
+
+No type information for this code.=== tests/cases/conformance/classes/members/privateNames/a.js ===
+class C {
+>C : C
+
+    /** @type {{ foo?: string } | undefined } */
+    #a;
+>#a : { foo?: string; }
+
+    /** @type {{ foo?: string } | undefined } */
+    #b;
+>#b : { foo?: string; }
+
+    m() {
+>m : () => void
+
+        const a = this.#a || {};
+>a : { foo?: string; }
+>this.#a || {} : { foo?: string; }
+>this.#a : { foo?: string; }
+>this : this
+>{} : {}
+
+        this.#b = this.#b || {};
+>this.#b = this.#b || {} : { foo?: string; }
+>this.#b : { foo?: string; }
+>this : this
+>this.#b || {} : { foo?: string; }
+>this.#b : { foo?: string; }
+>this : this
+>{} : {}
+    }
+}
+

tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignment.ts

@@ -0,0 +1,13 @@
+// @target: esnext
+
+type Foo = { foo?: string };
+
+class C {
+    #a?: Foo;
+    #b?: Foo;
+
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}

tests/cases/conformance/classes/members/privateNames/typeFromPrivatePropertyAssignmentJs.ts

@@ -0,0 +1,17 @@
+// @target: esnext
+// @allowJs: true
+// @checkJs: true
+// @outDir: ./out
+// @filename: typeFromPrivatePropertyAssignmentJs.js
+
+// @filename: a.js
+class C {
+    /** @type {{ foo?: string } | undefined } */
+    #a;
+    /** @type {{ foo?: string } | undefined } */
+    #b;
+    m() {
+        const a = this.#a || {};
+        this.#b = this.#b || {};
+    }
+}