Add HermesInternal.hasPromise

Summary: Add HermesInternal.hasPromise() which always returns false (for now).

Reviewed By: dulinriley

Differential Revision: D23486049

fbshipit-source-id: 9a3fdc7fda6a92ec521219224410546a4a62c76b

include/hermes/VM/NativeFunctions.def

@@ -151,6 +151,7 @@ NATIVE_FUNCTION(hermesInternalGetInstrumentedStats)
 NATIVE_FUNCTION(hermesInternalGetRuntimeProperties)
 NATIVE_FUNCTION(hermesInternalGetWeakSize)
 NATIVE_FUNCTION(hermesInternalIsProxy)
+NATIVE_FUNCTION(hermesInternalHasPromise)
 NATIVE_FUNCTION(hermesInternalTTIReached)
 NATIVE_FUNCTION(hermesInternalTTRCReached)
 

include/hermes/VM/PredefinedStrings.def

@@ -384,6 +384,7 @@ STR(revoke, "revoke")
 STR(HermesInternal, "HermesInternal")
 STR(detachArrayBuffer, "detachArrayBuffer")
 STR(createHeapSnapshot, "createHeapSnapshot")
+STR(hasPromise, "hasPromise")
 STR(getEpilogues, "getEpilogues")
 STR(getWeakSize, "getWeakSize")
 STR(silentSetPrototypeOf, "silentSetPrototypeOf")

lib/VM/JSLib/HermesInternal.cpp

@@ -546,6 +546,11 @@ hermesInternalIsProxy(void *, Runtime *runtime, NativeArgs args) {
   return HermesValue::encodeBoolValue(obj && obj->isProxyObject());
 }
 
+CallResult<HermesValue>
+hermesInternalHasPromise(void *, Runtime *runtime, NativeArgs args) {
+  return HermesValue::encodeBoolValue(false);
+}
+
 #ifdef HERMESVM_EXCEPTION_ON_OOM
 /// Gets the current call stack as a JS String value.  Intended (only)
 /// to allow testing of Runtime::callStack() from JS code.
@@ -795,6 +800,7 @@ Handle<JSObject> createHermesInternalObject(
       "Failed to set HermesInternal.concat.");
   (void)putRes;
 
+  defineInternMethod(P::hasPromise, hermesInternalHasPromise);
   defineInternMethod(
       P::setPromiseRejectionTrackingHook,
       hermesInternalSetPromiseRejectionTrackingHook);

test/hermes/internal-test-methods.js

@@ -11,9 +11,10 @@
 // RUN: %hermes -Xhermes-internal-test-methods=false %s | %FileCheck --match-full-lines --check-prefix=CHKIMD %s
 
 // concat
+// hasPromise
 // setPromiseRejectionTrackingHook
 // enablePromiseRejectionTracker
-var SAFE_FIELDS_COUNT = 3;
+var SAFE_FIELDS_COUNT = 4;
 
 // Check that we can disable unsafe fields of HermesInternal.
 print(Object.getOwnPropertyNames(HermesInternal).length !== SAFE_FIELDS_COUNT);

test/hermes/promise-disable.js

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// RUN: %hermes %s | %FileCheck --match-full-lines %s
+// RUN: %hermesc -O -emit-binary -out %t.hbc %s && %hermes %t.hbc | %FileCheck --match-full-lines %s
+
+print('promise-disable');
+// CHECK-LABEL: promise-disable
+
+print(HermesInternal.hasPromise());
+// CHECK-NEXT: false
+
+print(typeof Promise);
+// CHECK-NEXT: undefined