Add regression tests

Author: ahejlsberg

tests/baselines/reference/excessPropertyCheckWithEmptyObject.errors.txt

@@ -0,0 +1,36 @@
+tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts(4,23): error TS2304: Cannot find name 'window'.
+tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts(4,58): error TS2345: Argument of type '{ value: string; readonly: boolean; }' is not assignable to parameter of type 'PropertyDescriptor & ThisType<any>'.
+  Object literal may only specify known properties, and 'readonly' does not exist in type 'PropertyDescriptor & ThisType<any>'.
+tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts(9,30): error TS2322: Type '{ y: number; }' is not assignable to type 'A & ThisType<any>'.
+  Object literal may only specify known properties, and 'y' does not exist in type 'A & ThisType<any>'.
+tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts(14,34): error TS2322: Type '{ y: string; }' is not assignable to type 'Empty & { x: number; }'.
+  Object literal may only specify known properties, and 'y' does not exist in type 'Empty & { x: number; }'.
+
+
+==== tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts (4 errors) ====
+    // Repro from #14910
+    
+    // Excess property error expected here
+    Object.defineProperty(window, "prop", { value: "v1.0.0", readonly: false });
+                          ~~~~~~
+!!! error TS2304: Cannot find name 'window'.
+                                                             ~~~~~~~~~~~~~~~
+!!! error TS2345: Argument of type '{ value: string; readonly: boolean; }' is not assignable to parameter of type 'PropertyDescriptor & ThisType<any>'.
+!!! error TS2345:   Object literal may only specify known properties, and 'readonly' does not exist in type 'PropertyDescriptor & ThisType<any>'.
+    
+    interface A { x?: string }
+    
+    // Excess property error expected here
+    let a: A & ThisType<any> = { y: 10 };
+                                 ~~~~~
+!!! error TS2322: Type '{ y: number; }' is not assignable to type 'A & ThisType<any>'.
+!!! error TS2322:   Object literal may only specify known properties, and 'y' does not exist in type 'A & ThisType<any>'.
+    
+    interface Empty {}
+    
+    // Excess property error expected here
+    let x: Empty & { x: number } = { y: "hello" };
+                                     ~~~~~~~~~~
+!!! error TS2322: Type '{ y: string; }' is not assignable to type 'Empty & { x: number; }'.
+!!! error TS2322:   Object literal may only specify known properties, and 'y' does not exist in type 'Empty & { x: number; }'.
+    

tests/baselines/reference/excessPropertyCheckWithEmptyObject.js

@@ -0,0 +1,25 @@
+//// [excessPropertyCheckWithEmptyObject.ts]
+// Repro from #14910
+
+// Excess property error expected here
+Object.defineProperty(window, "prop", { value: "v1.0.0", readonly: false });
+
+interface A { x?: string }
+
+// Excess property error expected here
+let a: A & ThisType<any> = { y: 10 };
+
+interface Empty {}
+
+// Excess property error expected here
+let x: Empty & { x: number } = { y: "hello" };
+
+
+//// [excessPropertyCheckWithEmptyObject.js]
+// Repro from #14910
+// Excess property error expected here
+Object.defineProperty(window, "prop", { value: "v1.0.0", readonly: false });
+// Excess property error expected here
+var a = { y: 10 };
+// Excess property error expected here
+var x = { y: "hello" };

tests/cases/compiler/excessPropertyCheckWithEmptyObject.ts

@@ -0,0 +1,14 @@
+// Repro from #14910
+
+// Excess property error expected here
+Object.defineProperty(window, "prop", { value: "v1.0.0", readonly: false });
+
+interface A { x?: string }
+
+// Excess property error expected here
+let a: A & ThisType<any> = { y: 10 };
+
+interface Empty {}
+
+// Excess property error expected here
+let x: Empty & { x: number } = { y: "hello" };