Implement Array.prototype.every and Array.prototype.some in JS

Summary: Implement `Array.prototype.every` and `Array.prototype.some` in JS Reviewed By: dulinriley Differential Revision: D17619231 fbshipit-source-id: 8b85b1b74a759916ad91e45009b2d7eab947f0c9
wade1990 · Oct 10, 2019 · 32e1fc1 · 32e1fc1
1 parent 39a3126
commit 32e1fc1
Show file tree

Hide file tree

Showing 5 changed files with 277 additions and 110 deletions.
diff --git a/include/hermes/VM/NativeFunctions.def b/include/hermes/VM/NativeFunctions.def
@@ -40,7 +40,6 @@ NATIVE_FUNCTION(arrayIteratorPrototypeNext)
 NATIVE_FUNCTION(arrayOf)
 NATIVE_FUNCTION(arrayPrototypeConcat)
 NATIVE_FUNCTION(arrayPrototypeCopyWithin)
-NATIVE_FUNCTION(arrayPrototypeEvery)
 NATIVE_FUNCTION(arrayPrototypeFill)
 NATIVE_FUNCTION(arrayPrototypeFilter)
 NATIVE_FUNCTION(arrayPrototypeFind)
@@ -54,18 +53,19 @@ NATIVE_FUNCTION(arrayPrototypeReduce)
 NATIVE_FUNCTION(arrayPrototypeReduceRight)
 NATIVE_FUNCTION(arrayPrototypeShift)
 NATIVE_FUNCTION(arrayPrototypeSlice)
-NATIVE_FUNCTION(arrayPrototypeSome)
 NATIVE_FUNCTION(arrayPrototypeSort)
 NATIVE_FUNCTION(arrayPrototypeSplice)
 NATIVE_FUNCTION(arrayPrototypeToLocaleString)
 NATIVE_FUNCTION(arrayPrototypeToString)
 NATIVE_FUNCTION(arrayPrototypeUnshift)
 
 #ifndef HERMESVM_USE_JS_LIBRARY_IMPLEMENTATION
+NATIVE_FUNCTION(arrayPrototypeEvery)
 NATIVE_FUNCTION(arrayPrototypeIndexOf)
 NATIVE_FUNCTION(arrayPrototypeLastIndexOf)
 NATIVE_FUNCTION(arrayPrototypeMap)
 NATIVE_FUNCTION(arrayPrototypeReverse)
+NATIVE_FUNCTION(arrayPrototypeSome)
 #endif // HERMESVM_USE_JS_LIBRARY_IMPLEMENTATION
 
 NATIVE_FUNCTION(booleanConstructor)

diff --git a/lib/InternalBytecode/Array.js b/lib/InternalBytecode/Array.js
@@ -248,6 +248,107 @@ Array.prototype.lastIndexOf = function lastIndexOf(searchElement, fromIndex = un
   return arrayPrototypeIndexOfHelper(this, searchElement, fromIndex, arguments.length > 1, true);
 }
 
+/**
+ * Helper function for Array.prototype.every and Array.prototypr.some,
+ * see their docuemntations for more details.
+ * @this an array-like value.
+ * @param callbackfn function to be invoked on the elements.
+ * @param thisArg parameter which will be used as the <this> value
+ *                for each invocation of callbackfn.
+ * @return In case of every, return true if callbackfn returns true for
+ *         all elements in the array, false otherwise.
+ *         In case of some, return false if callbackfn returns false for
+ *         all elements in the array, true otherwise.
+ * @throw TypeError if callbackfn is not a function
+ */
+function arrayPrototypeEverySomeHelper(arr, callbackfn, thisArg, isEvery) {
+  // Array.prototype.every and Array.prototype.some cannot be used as constructors
+  if (new.target) throw _TypeError('This function cannot be used as a constructor.');
+
+  // 1. Let O be ? ToObject(this value).
+  var O = HermesInternal.toObject(arr);
+  // 2. Let len be ? ToLength(? Get(O, "length")).
+  var len = HermesInternal.toLength(O.length);
+
+  // 3. If IsCallable(callbackfn) is false, throw a TypeError exception.
+  if (typeof callbackfn !== 'function') {
+    if (isEvery) throw _TypeError('Array.prototype.every() requires a callable argument');
+    throw _TypeError('Array.prototype.some() requires a callable argument');
+  }
+
+  // 4. If thisArg is present, let T be thisArg; else let T be undefined.
+
+  // 5. Let k be 0.
+  var k = 0;
+
+  // fast path which calls the function directly when thisArg is undefined
+  if (thisArg === undefined) {
+    while (k < len) {
+      if (k in O) {
+        var testResult = callbackfn(O[k], k, O);
+        if (isEvery && !testResult) return false;
+        if (!isEvery && testResult) return true;
+      }
+      k += 1;
+    }
+    return isEvery ? true : false;
+  }
+
+  // 6. Repeat, while k < len
+  while (k < len) {
+    // a. Let Pk be ! ToString(k).
+    // b. Let kPresent be ? HasProperty(O, Pk).
+    // c. If kPresent is true, then
+    if (k in O) {
+      // i. Let kValue be ? Get(O, Pk).
+      // ii. Let Let testResult be ToBoolean(? Call(callbackfn, T, « kValue, k, O »)).
+      var testResult = !!HermesInternal.executeCall(callbackfn, thisArg, O[k], k, O);
+      // iii. If testResult is false, return false. (every)
+      //      If testResult is false, return false. (some)
+      if (isEvery && !testResult) return false;
+      if (!isEvery && testResult) return true;
+    }
+    // d. Increase k by 1.
+    k += 1;
+  }
+
+  // 7. Return true. (every)
+  //    Return false. (some)
+  return isEvery;
+}
+
+/**
+ * ES10.0 22.1.3.5
+ * Invoke a callback function on elements in an array-like object until
+ * a return value is falsy or there's no more elments.
+ * @this an array-like value.
+ * @param callbackfn function to be invoked on the elements.
+ * @param [thisArg] optional parameter which will be used as the <this> value
+ *                  for each invocation of callbackfn.
+ * @return true if callbackfn returns true for all elements in the array,
+ *         false otherwise.
+ * @throw TypeError if callbackfn is not a function
+ */
+Array.prototype.every = function every(callbackfn, thisArg = undefined) {
+  return arrayPrototypeEverySomeHelper(this, callbackfn, thisArg, true);
+}
+
+/**
+ * ES10.0 22.1.3.26
+ * Invoke a callback function on elements in an array-like object until
+ * a return value is truthy or there's no more elments.
+ * @this an array-like value.
+ * @param callbackfn function to be invoked on the elements.
+ * @param [thisArg] optional parameter which will be used as the <this> value
+ *                  for each invocation of callbackfn.
+ * @return false if callbackfn returns false for all elements in the array,
+ *         true otherwise.
+ * @throw TypeError if callbackfn is not a function
+ */
+Array.prototype.some = function some(callbackfn, thisArg = undefined) {
+  return arrayPrototypeEverySomeHelper(this, callbackfn, thisArg, false);
+}
+
 var arrayFuncDescriptor = {
   configurable: true,
   enumerable: false,
@@ -258,8 +359,12 @@ Object.defineProperty(Array.prototype, 'reverse', arrayFuncDescriptor);
 Object.defineProperty(Array.prototype, 'map', arrayFuncDescriptor);
 Object.defineProperty(Array.prototype, 'indexOf', arrayFuncDescriptor);
 Object.defineProperty(Array.prototype, 'lastIndexOf', arrayFuncDescriptor);
+Object.defineProperty(Array.prototype, 'every', arrayFuncDescriptor);
+Object.defineProperty(Array.prototype, 'some', arrayFuncDescriptor);
 
 Array.prototype.reverse.prototype = undefined;
 Array.prototype.map.prototype = undefined;
 Array.prototype.indexOf.prototype = undefined;
 Array.prototype.lastIndexOf.prototype = undefined;
+Array.prototype.every.prototype = undefined;
+Array.prototype.some.prototype = undefined;
diff --git a/lib/VM/JSLib/Array.cpp b/lib/VM/JSLib/Array.cpp
@@ -110,20 +110,6 @@ Handle<JSObject> createArrayConstructor(Runtime *runtime) {
       nullptr,
       arrayPrototypeUnshift,
       1);
-  defineMethod(
-      runtime,
-      arrayPrototype,
-      Predefined::getSymbolID(Predefined::every),
-      nullptr,
-      arrayPrototypeEvery,
-      1);
-  defineMethod(
-      runtime,
-      arrayPrototype,
-      Predefined::getSymbolID(Predefined::some),
-      nullptr,
-      arrayPrototypeSome,
-      1);
   defineMethod(
       runtime,
       arrayPrototype,
@@ -218,6 +204,20 @@ Handle<JSObject> createArrayConstructor(Runtime *runtime) {
       nullptr,
       arrayPrototypeLastIndexOf,
       1);
+  defineMethod(
+      runtime,
+      arrayPrototype,
+      Predefined::getSymbolID(Predefined::every),
+      nullptr,
+      arrayPrototypeEvery,
+      1);
+  defineMethod(
+      runtime,
+      arrayPrototype,
+      Predefined::getSymbolID(Predefined::some),
+      nullptr,
+      arrayPrototypeSome,
+      1);
   defineMethod(
       runtime,
       arrayPrototype,
@@ -2054,100 +2054,6 @@ arrayPrototypeUnshift(void *, Runtime *runtime, NativeArgs args) {
   return newLen;
 }
 
-/// Helper function for every/some.
-/// \param every true if calling every(), false if calling some().
-static inline CallResult<HermesValue>
-everySomeHelper(Runtime *runtime, NativeArgs args, const bool every) {
-  GCScope gcScope(runtime);
-  auto objRes = toObject(runtime, args.getThisHandle());
-  if (LLVM_UNLIKELY(objRes == ExecutionStatus::EXCEPTION)) {
-    return ExecutionStatus::EXCEPTION;
-  }
-  auto O = runtime->makeHandle<JSObject>(objRes.getValue());
-
-  auto propRes = JSObject::getNamed_RJS(
-      O, runtime, Predefined::getSymbolID(Predefined::length));
-  if (LLVM_UNLIKELY(propRes == ExecutionStatus::EXCEPTION)) {
-    return ExecutionStatus::EXCEPTION;
-  }
-  auto intRes = toLengthU64(runtime, runtime->makeHandle(*propRes));
-  if (LLVM_UNLIKELY(intRes == ExecutionStatus::EXCEPTION)) {
-    return ExecutionStatus::EXCEPTION;
-  }
-  uint64_t len = *intRes;
-
-  auto callbackFn = args.dyncastArg<Callable>(0);
-  if (!callbackFn) {
-    return runtime->raiseTypeError(
-        "Array.prototype.every() requires a callable argument");
-  }
-
-  // Index to check the callback on.
-  MutableHandle<> k{runtime, HermesValue::encodeDoubleValue(0)};
-
-  // Value at index k;
-  MutableHandle<JSObject> descObjHandle{runtime};
-  MutableHandle<> kValue{runtime};
-
-  // Loop through and run the callback.
-  auto marker = gcScope.createMarker();
-  while (k->getDouble() < len) {
-    gcScope.flushToMarker(marker);
-
-    ComputedPropertyDescriptor desc;
-    JSObject::getComputedPrimitiveDescriptor(
-        O, runtime, k, descObjHandle, desc);
-
-    if (descObjHandle) {
-      // kPresent is true, call the callback on the kth element.
-      if ((propRes = JSObject::getComputedPropertyValue(
-               O, runtime, descObjHandle, desc)) ==
-          ExecutionStatus::EXCEPTION) {
-        return ExecutionStatus::EXCEPTION;
-      }
-      kValue = propRes.getValue();
-      auto callRes = Callable::executeCall3(
-          callbackFn,
-          runtime,
-          args.getArgHandle(1),
-          kValue.get(),
-          k.get(),
-          O.getHermesValue());
-      if (LLVM_UNLIKELY(callRes == ExecutionStatus::EXCEPTION)) {
-        return ExecutionStatus::EXCEPTION;
-      }
-      auto testResult = *callRes;
-      if (every) {
-        // Done if one is false.
-        if (!toBoolean(testResult)) {
-          return HermesValue::encodeBoolValue(false);
-        }
-      } else {
-        // Done if one is true.
-        if (toBoolean(testResult)) {
-          return HermesValue::encodeBoolValue(true);
-        }
-      }
-    }
-
-    k = HermesValue::encodeDoubleValue(k->getDouble() + 1);
-  }
-
-  // If we're looking for every, then we finished without returning true.
-  // If we're looking for some, then we finished without returning false.
-  return HermesValue::encodeBoolValue(every);
-}
-
-CallResult<HermesValue>
-arrayPrototypeEvery(void *, Runtime *runtime, NativeArgs args) {
-  return everySomeHelper(runtime, args, true);
-}
-
-CallResult<HermesValue>
-arrayPrototypeSome(void *, Runtime *runtime, NativeArgs args) {
-  return everySomeHelper(runtime, args, false);
-}
-
 inline CallResult<HermesValue>
 arrayPrototypeForEach(void *, Runtime *runtime, NativeArgs args) {
   GCScope gcScope(runtime);
@@ -3013,6 +2919,100 @@ arrayPrototypeLastIndexOf(void *, Runtime *runtime, NativeArgs args) {
   return indexOfHelper(runtime, args, true);
 }
 
+/// Helper function for every/some.
+/// \param every true if calling every(), false if calling some().
+static inline CallResult<HermesValue>
+everySomeHelper(Runtime *runtime, NativeArgs args, const bool every) {
+  GCScope gcScope(runtime);
+  auto objRes = toObject(runtime, args.getThisHandle());
+  if (LLVM_UNLIKELY(objRes == ExecutionStatus::EXCEPTION)) {
+    return ExecutionStatus::EXCEPTION;
+  }
+  auto O = runtime->makeHandle<JSObject>(objRes.getValue());
+
+  auto propRes = JSObject::getNamed_RJS(
+      O, runtime, Predefined::getSymbolID(Predefined::length));
+  if (LLVM_UNLIKELY(propRes == ExecutionStatus::EXCEPTION)) {
+    return ExecutionStatus::EXCEPTION;
+  }
+  auto intRes = toLengthU64(runtime, runtime->makeHandle(*propRes));
+  if (LLVM_UNLIKELY(intRes == ExecutionStatus::EXCEPTION)) {
+    return ExecutionStatus::EXCEPTION;
+  }
+  uint64_t len = *intRes;
+
+  auto callbackFn = args.dyncastArg<Callable>(0);
+  if (!callbackFn) {
+    return runtime->raiseTypeError(
+        "Array.prototype.every() requires a callable argument");
+  }
+
+  // Index to check the callback on.
+  MutableHandle<> k{runtime, HermesValue::encodeDoubleValue(0)};
+
+  // Value at index k;
+  MutableHandle<JSObject> descObjHandle{runtime};
+  MutableHandle<> kValue{runtime};
+
+  // Loop through and run the callback.
+  auto marker = gcScope.createMarker();
+  while (k->getDouble() < len) {
+    gcScope.flushToMarker(marker);
+
+    ComputedPropertyDescriptor desc;
+    JSObject::getComputedPrimitiveDescriptor(
+        O, runtime, k, descObjHandle, desc);
+
+    if (descObjHandle) {
+      // kPresent is true, call the callback on the kth element.
+      if ((propRes = JSObject::getComputedPropertyValue(
+               O, runtime, descObjHandle, desc)) ==
+          ExecutionStatus::EXCEPTION) {
+        return ExecutionStatus::EXCEPTION;
+      }
+      kValue = propRes.getValue();
+      auto callRes = Callable::executeCall3(
+          callbackFn,
+          runtime,
+          args.getArgHandle(1),
+          kValue.get(),
+          k.get(),
+          O.getHermesValue());
+      if (LLVM_UNLIKELY(callRes == ExecutionStatus::EXCEPTION)) {
+        return ExecutionStatus::EXCEPTION;
+      }
+      auto testResult = *callRes;
+      if (every) {
+        // Done if one is false.
+        if (!toBoolean(testResult)) {
+          return HermesValue::encodeBoolValue(false);
+        }
+      } else {
+        // Done if one is true.
+        if (toBoolean(testResult)) {
+          return HermesValue::encodeBoolValue(true);
+        }
+      }
+    }
+
+    k = HermesValue::encodeDoubleValue(k->getDouble() + 1);
+  }
+
+  // If we're looking for every, then we finished without returning true.
+  // If we're looking for some, then we finished without returning false.
+  return HermesValue::encodeBoolValue(every);
+}
+
+CallResult<HermesValue>
+arrayPrototypeEvery(void *, Runtime *runtime, NativeArgs args) {
+  return everySomeHelper(runtime, args, true);
+}
+
+CallResult<HermesValue>
+arrayPrototypeSome(void *, Runtime *runtime, NativeArgs args) {
+  return everySomeHelper(runtime, args, false);
+}
+
 CallResult<HermesValue>
 arrayPrototypeMap(void *, Runtime *runtime, NativeArgs args) {
   GCScope gcScope(runtime);