Ensure functions that have prototype properties assigned by Object.defineProperty get marked as classes

src/compiler/binder.ts

@@ -2789,6 +2789,10 @@ namespace ts {
 
         function bindObjectDefinePrototypeProperty(node: BindableObjectDefinePropertyCall) {
             const namespaceSymbol = lookupSymbolForPropertyAccess((node.arguments[0] as PropertyAccessExpression).expression as EntityNameExpression);
+            if (namespaceSymbol) {
+                // Ensure the namespace symbol becomes class-like
+                addDeclarationToSymbol(namespaceSymbol, namespaceSymbol.valueDeclaration, SymbolFlags.Class);
+            }
             bindPotentiallyNewExpandoMemberToNamespace(node, namespaceSymbol, /*isPrototypeProperty*/ true);
         }
 

tests/baselines/reference/javascriptDefinePropertyPrototypeNonConstructor.symbols

@@ -0,0 +1,23 @@
+=== /a.js ===
+function Graphic() {
+>Graphic : Symbol(Graphic, Decl(a.js, 0, 0))
+}
+
+Object.defineProperty(Graphic.prototype, "instance", {
+>Object.defineProperty : Symbol(ObjectConstructor.defineProperty, Decl(lib.es5.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>defineProperty : Symbol(ObjectConstructor.defineProperty, Decl(lib.es5.d.ts, --, --))
+>Graphic.prototype : Symbol(Function.prototype, Decl(lib.es5.d.ts, --, --))
+>Graphic : Symbol(Graphic, Decl(a.js, 0, 0))
+>prototype : Symbol(Function.prototype, Decl(lib.es5.d.ts, --, --))
+>"instance" : Symbol(Graphic.instance, Decl(a.js, 1, 1))
+
+  get: function() {
+>get : Symbol(get, Decl(a.js, 3, 54))
+
+    return this;
+>this : Symbol(Graphic, Decl(a.js, 0, 0))
+  }
+});
+
+

tests/baselines/reference/javascriptDefinePropertyPrototypeNonConstructor.types

@@ -0,0 +1,26 @@
+=== /a.js ===
+function Graphic() {
+>Graphic : typeof Graphic
+}
+
+Object.defineProperty(Graphic.prototype, "instance", {
+>Object.defineProperty(Graphic.prototype, "instance", {  get: function() {    return this;  }}) : any
+>Object.defineProperty : (o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any
+>Object : ObjectConstructor
+>defineProperty : (o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any
+>Graphic.prototype : any
+>Graphic : typeof Graphic
+>prototype : any
+>"instance" : "instance"
+>{  get: function() {    return this;  }} : { get: () => this; }
+
+  get: function() {
+>get : () => this
+>function() {    return this;  } : () => this
+
+    return this;
+>this : this
+  }
+});
+
+

tests/cases/compiler/javascriptDefinePropertyPrototypeNonConstructor.ts

@@ -0,0 +1,14 @@
+// @allowJs: true
+// @checkJs: false
+// @noEmit: true
+// @Filename: /a.js
+
+function Graphic() {
+}
+
+Object.defineProperty(Graphic.prototype, "instance", {
+  get: function() {
+    return this;
+  }
+});
+