Add test case for nested object spread / methods

See microsoft#16765.

Author: Yogu

tests/baselines/reference/objectSpreadWithinMethodWithinObjectWithSpread.js

@@ -0,0 +1,26 @@
+//// [objectSpreadWithinMethodWithinObjectWithSpread.ts]
+const obj = {};
+const a = {
+    ...obj,
+    prop() {
+        return {
+            ...obj,
+            metadata: 213
+        };
+    }
+};
+
+
+//// [objectSpreadWithinMethodWithinObjectWithSpread.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var obj = {};
+var a = __assign({}, obj, { prop: function () {
+        return __assign({}, obj, { metadata: 213 });
+    } });

tests/baselines/reference/objectSpreadWithinMethodWithinObjectWithSpread.symbols

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/objectSpreadWithinMethodWithinObjectWithSpread.ts ===
+const obj = {};
+>obj : Symbol(obj, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 0, 5))
+
+const a = {
+>a : Symbol(a, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 1, 5))
+
+    ...obj,
+>obj : Symbol(obj, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 0, 5))
+
+    prop() {
+>prop : Symbol(prop, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 2, 11))
+
+        return {
+            ...obj,
+>obj : Symbol(obj, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 0, 5))
+
+            metadata: 213
+>metadata : Symbol(metadata, Decl(objectSpreadWithinMethodWithinObjectWithSpread.ts, 5, 19))
+
+        };
+    }
+};
+

tests/baselines/reference/objectSpreadWithinMethodWithinObjectWithSpread.types

@@ -0,0 +1,29 @@
+=== tests/cases/compiler/objectSpreadWithinMethodWithinObjectWithSpread.ts ===
+const obj = {};
+>obj : {}
+>{} : {}
+
+const a = {
+>a : { prop(): { metadata: number; }; }
+>{    ...obj,    prop() {        return {            ...obj,            metadata: 213        };    }} : { prop(): { metadata: number; }; }
+
+    ...obj,
+>obj : {}
+
+    prop() {
+>prop : () => { metadata: number; }
+
+        return {
+>{            ...obj,            metadata: 213        } : { metadata: number; }
+
+            ...obj,
+>obj : {}
+
+            metadata: 213
+>metadata : number
+>213 : 213
+
+        };
+    }
+};
+

tests/cases/compiler/objectSpreadWithinMethodWithinObjectWithSpread.ts

@@ -0,0 +1,10 @@
+const obj = {};
+const a = {
+    ...obj,
+    prop() {
+        return {
+            ...obj,
+            metadata: 213
+        };
+    }
+};