Bug 1472170- Added description as a property for Symbol and updated tests262. r=anba

js/src/builtin/Symbol.cpp

@@ -31,6 +31,7 @@ SymbolObject::create(JSContext* cx, JS::HandleSymbol symbol)
 }
 
 const JSPropertySpec SymbolObject::properties[] = {
+    JS_PSG("description", descriptionGetter, 0),
     JS_PS_END
 };
 
@@ -231,6 +232,31 @@ SymbolObject::toPrimitive(JSContext* cx, unsigned argc, Value* vp)
     return CallNonGenericMethod<IsSymbol, valueOf_impl>(cx, args);
 }
 
+bool
+SymbolObject::descriptionGetter_impl(JSContext* cx, const CallArgs& args)
+{
+    // Get symbol object pointer.
+    HandleValue thisv = args.thisv();
+    MOZ_ASSERT(IsSymbol(thisv));
+    Rooted<Symbol*> sym(cx, thisv.isSymbol()
+                            ? thisv.toSymbol()
+                            : thisv.toObject().as<SymbolObject>().unbox());
+
+    // Return the symbol's description if present, otherwise return undefined.
+    if (JSString* str = sym->description())
+        args.rval().setString(str);
+    else
+        args.rval().setUndefined();
+    return true;
+}
+
+bool
+SymbolObject::descriptionGetter(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsSymbol, descriptionGetter_impl>(cx, args);
+}
+
 JSObject*
 js::InitSymbolClass(JSContext* cx, Handle<GlobalObject*> global)
 {

js/src/builtin/Symbol.h

@@ -54,6 +54,10 @@ class SymbolObject : public NativeObject
     static MOZ_MUST_USE bool valueOf(JSContext* cx, unsigned argc, Value* vp);
     static MOZ_MUST_USE bool toPrimitive(JSContext* cx, unsigned argc, Value* vp);
 
+    // Properties defined on Symbol.prototype.
+    static MOZ_MUST_USE bool descriptionGetter_impl(JSContext* cx, const CallArgs& args);
+    static MOZ_MUST_USE bool descriptionGetter(JSContext* cx, unsigned argc, Value *vp);
+
     static const JSPropertySpec properties[];
     static const JSFunctionSpec methods[];
     static const JSFunctionSpec staticMethods[];

js/src/tests/test262-update.py

@@ -30,7 +30,6 @@ UNSUPPORTED_FEATURES = set([
     "Intl.Locale",
     "String.prototype.matchAll",
     "Symbol.matchAll",
-    "Symbol.prototype.description",
     "global",
     "export-star-as-namespace-from-module",
 ])

js/src/tests/test262/built-ins/Symbol/prototype/description/description-symboldescriptivestring.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // Copyright (C) 2018 the V8 project authors. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.

js/src/tests/test262/built-ins/Symbol/prototype/description/descriptor.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 

js/src/tests/test262/built-ins/Symbol/prototype/description/get.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 

js/src/tests/test262/built-ins/Symbol/prototype/description/is-not-own-property.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 

js/src/tests/test262/built-ins/Symbol/prototype/description/this-val-non-symbol.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 

js/src/tests/test262/built-ins/Symbol/prototype/description/this-val-symbol.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 

js/src/tests/test262/built-ins/Symbol/prototype/description/wrapper.js

@@ -1,4 +1,3 @@
-// |reftest| skip -- Symbol.prototype.description is not supported
 // Copyright 2018 Igalia, S.L. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.