add extra test case

Author: Andarist

tests/baselines/reference/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.js

@@ -0,0 +1,45 @@
+//// [tests/cases/conformance/expressions/nullishCoalescingOperator/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts] ////
+
+//// [nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts]
+// https://github.com/microsoft/TypeScript/issues/61109
+
+class Cls {
+  #privateProp: number | undefined;
+
+  problem() {
+    this.#privateProp ??= false ? neverThis() : 20;
+  }
+}
+
+function neverThis(): never {
+  throw new Error("This should really really never happen!");
+}
+
+
+//// [nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.js]
+"use strict";
+// https://github.com/microsoft/TypeScript/issues/61109
+var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
+    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
+};
+var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
+    if (kind === "m") throw new TypeError("Private method is not writable");
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
+    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
+};
+var _Cls_privateProp;
+class Cls {
+    constructor() {
+        _Cls_privateProp.set(this, void 0);
+    }
+    problem() {
+        __classPrivateFieldSet(this, _Cls_privateProp, __classPrivateFieldGet(this, _Cls_privateProp, "f") ?? (false ? neverThis() : 20), "f");
+    }
+}
+_Cls_privateProp = new WeakMap();
+function neverThis() {
+    throw new Error("This should really really never happen!");
+}

tests/baselines/reference/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.symbols

@@ -0,0 +1,28 @@
+//// [tests/cases/conformance/expressions/nullishCoalescingOperator/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts] ////
+
+=== nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts ===
+// https://github.com/microsoft/TypeScript/issues/61109
+
+class Cls {
+>Cls : Symbol(Cls, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 0, 0))
+
+  #privateProp: number | undefined;
+>#privateProp : Symbol(Cls.#privateProp, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 2, 11))
+
+  problem() {
+>problem : Symbol(Cls.problem, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 3, 35))
+
+    this.#privateProp ??= false ? neverThis() : 20;
+>this.#privateProp : Symbol(Cls.#privateProp, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 2, 11))
+>this : Symbol(Cls, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 0, 0))
+>neverThis : Symbol(neverThis, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 8, 1))
+  }
+}
+
+function neverThis(): never {
+>neverThis : Symbol(neverThis, Decl(nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts, 8, 1))
+
+  throw new Error("This should really really never happen!");
+>Error : Symbol(Error, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+}
+

tests/baselines/reference/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.types

@@ -0,0 +1,50 @@
+//// [tests/cases/conformance/expressions/nullishCoalescingOperator/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts] ////
+
+=== nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts ===
+// https://github.com/microsoft/TypeScript/issues/61109
+
+class Cls {
+>Cls : Cls
+>    : ^^^
+
+  #privateProp: number | undefined;
+>#privateProp : number | undefined
+>             : ^^^^^^^^^^^^^^^^^^
+
+  problem() {
+>problem : () => void
+>        : ^^^^^^^^^^
+
+    this.#privateProp ??= false ? neverThis() : 20;
+>this.#privateProp ??= false ? neverThis() : 20 : number
+>                                               : ^^^^^^
+>this.#privateProp : number | undefined
+>                  : ^^^^^^^^^^^^^^^^^^
+>this : this
+>     : ^^^^
+>false ? neverThis() : 20 : 20
+>                         : ^^
+>false : false
+>      : ^^^^^
+>neverThis() : never
+>            : ^^^^^
+>neverThis : () => never
+>          : ^^^^^^     
+>20 : 20
+>   : ^^
+  }
+}
+
+function neverThis(): never {
+>neverThis : () => never
+>          : ^^^^^^     
+
+  throw new Error("This should really really never happen!");
+>new Error("This should really really never happen!") : Error
+>                                                     : ^^^^^
+>Error : ErrorConstructor
+>      : ^^^^^^^^^^^^^^^^
+>"This should really really never happen!" : "This should really really never happen!"
+>                                          : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+}
+

tests/cases/conformance/expressions/nullishCoalescingOperator/nullishCoalescingAssignmentVsPrivateFieldsJsEmit1.ts

@@ -0,0 +1,16 @@
+// @strict: true
+// @target: es2021
+
+// https://github.com/microsoft/TypeScript/issues/61109
+
+class Cls {
+  #privateProp: number | undefined;
+
+  problem() {
+    this.#privateProp ??= false ? neverThis() : 20;
+  }
+}
+
+function neverThis(): never {
+  throw new Error("This should really really never happen!");
+}