Bug 1216751 part 4. Implement forEach for iterable interfaces. r=qdot

dom/bindings/Codegen.py

@@ -2289,7 +2289,7 @@ class MethodDefiner(PropertyDefiner):
             maplikeOrSetlikeOrIterable and
             maplikeOrSetlikeOrIterable.isIterable() and
             maplikeOrSetlikeOrIterable.isValueIterator()):
-            # Add our keys/values/entries
+            # Add our keys/values/entries/forEach
             self.regular.append({
                 "name": "keys",
                 "methodInfo": False,
@@ -2317,6 +2317,15 @@ class MethodDefiner(PropertyDefiner):
                 "condition": PropertyDefiner.getControllingCondition(m,
                                                                      descriptor)
             })
+            self.regular.append({
+                "name": "forEach",
+                "methodInfo": False,
+                "selfHostedName": "ArrayForEach",
+                "length": 0,
+                "flags": "JSPROP_ENUMERATE",
+                "condition": PropertyDefiner.getControllingCondition(m,
+                                                                     descriptor)
+            })
 
         if not static:
             stringifier = descriptor.operations['Stringifier']
@@ -15811,6 +15820,31 @@ class CGIterableMethodGenerator(CGGeneric):
     using CGCallGenerator.
     """
     def __init__(self, descriptor, iterable, methodName):
+        if methodName == "forEach":
+            CGGeneric.__init__(self, fill(
+                """
+                if (!JS::IsCallable(arg0)) {
+                  ThrowErrorMessage(cx, MSG_NOT_CALLABLE, "Argument 1 of ${ifaceName}.forEach");
+                  return false;
+                }
+                JS::AutoValueArray<3> callArgs(cx);
+                callArgs[2].setObject(*obj);
+                JS::Rooted<JS::Value> ignoredReturnVal(cx);
+                for (size_t i = 0; i < self->GetIterableLength(); ++i) {
+                  if (!ToJSValue(cx, self->GetValueAtIndex(i), callArgs[0])) {
+                    return false;
+                  }
+                  if (!ToJSValue(cx, self->GetKeyAtIndex(i), callArgs[1])) {
+                    return false;
+                  }
+                  if (!JS::Call(cx, arg1, arg0, JS::HandleValueArray(callArgs),
+                                &ignoredReturnVal)) {
+                    return false;
+                  }
+                }
+                """,
+                ifaceName=descriptor.interface.identifier.name))
+            return
         CGGeneric.__init__(self, fill(
             """
             typedef ${iterClass} itrType;

dom/bindings/parser/WebIDL.py

@@ -3617,6 +3617,17 @@ class IDLMaplikeOrSetlikeOrIterableBase(IDLInterfaceMember):
             deps.add(self.valueType)
         return deps
 
+    def getForEachArguments(self):
+        return [IDLArgument(self.location,
+                            IDLUnresolvedIdentifier(BuiltinLocation("<auto-generated-identifier>"),
+                                                    "callback"),
+                            BuiltinTypes[IDLBuiltinType.Types.object]),
+                IDLArgument(self.location,
+                            IDLUnresolvedIdentifier(BuiltinLocation("<auto-generated-identifier>"),
+                                                    "thisArg"),
+                            BuiltinTypes[IDLBuiltinType.Types.any],
+                            optional=True)]
+
 # Iterable adds ES6 iterator style functions and traits
 # (keys/values/entries/@@iterator) to an interface.
 class IDLIterable(IDLMaplikeOrSetlikeOrIterableBase):
@@ -3652,6 +3663,11 @@ class IDLIterable(IDLMaplikeOrSetlikeOrIterableBase):
         self.addMethod("values", members, False, self.iteratorType,
                        affectsNothing=True, newObject=True)
 
+        # void forEach(callback(valueType, keyType), optional any thisArg)
+        self.addMethod("forEach", members, False,
+                       BuiltinTypes[IDLBuiltinType.Types.void],
+                       self.getForEachArguments())
+
     def isValueIterator(self):
         return not self.isPairIterator()
 
@@ -3703,17 +3719,8 @@ class IDLMaplikeOrSetlike(IDLMaplikeOrSetlikeOrIterableBase):
                        affectsNothing=True, isIteratorAlias=self.isSetlike())
 
         # void forEach(callback(valueType, keyType), thisVal)
-        foreachArguments = [IDLArgument(self.location,
-                                        IDLUnresolvedIdentifier(BuiltinLocation("<auto-generated-identifier>"),
-                                                                "callback"),
-                                        BuiltinTypes[IDLBuiltinType.Types.object]),
-                            IDLArgument(self.location,
-                                        IDLUnresolvedIdentifier(BuiltinLocation("<auto-generated-identifier>"),
-                                                                "thisArg"),
-                                        BuiltinTypes[IDLBuiltinType.Types.any],
-                                        optional=True)]
         self.addMethod("forEach", members, False, BuiltinTypes[IDLBuiltinType.Types.void],
-                       foreachArguments)
+                       self.getForEachArguments())
 
         def getKeyArg():
             return IDLArgument(self.location,

dom/bindings/parser/tests/test_interface_maplikesetlikeiterable.py

@@ -45,8 +45,8 @@ def WebIDLTest(parser, harness):
                        prefix + " - Interface failed but not as a WebIDLError exception: %s" % e)
 
     iterableMembers = [(x, WebIDL.IDLMethod) for x in ["entries", "keys",
-                                                       "values"]]
+                                                       "values", "forEach"]]
-    setROMembers = ([(x, WebIDL.IDLMethod) for x in ["has", "forEach"]] +
+    setROMembers = ([(x, WebIDL.IDLMethod) for x in ["has"]] +
                     [("__setlike", WebIDL.IDLMaplikeOrSetlike)] +
                     iterableMembers)
     setROMembers.extend([("size", WebIDL.IDLAttribute)])
@@ -62,7 +62,7 @@ def WebIDLTest(parser, harness):
                                                            "__clear",
                                                            "__delete"]] +
                           setRWMembers)
-    mapROMembers = ([(x, WebIDL.IDLMethod) for x in ["get", "has", "forEach"]] +
+    mapROMembers = ([(x, WebIDL.IDLMethod) for x in ["get", "has"]] +
                     [("__maplike", WebIDL.IDLMaplikeOrSetlike)] +
                     iterableMembers)
     mapROMembers.extend([("size", WebIDL.IDLAttribute)])

dom/bindings/test/test_iterable.html

@@ -14,7 +14,8 @@
 
        base_properties = [["entries", "function", 0],
                           ["keys", "function", 0],
-                          ["values", "function", 0]]
+                          ["values", "function", 0],
+                          ["forEach", "function", 1]]
        var testExistence = function testExistence(prefix, obj, properties) {
          for (var [name, type, args] of properties) {
            // Properties are somewhere up the proto chain, hasOwnProperty won't work
@@ -58,6 +59,8 @@
           "IterableSingle: Should be using %ArrayIterator% for 'entries'");
        is(itr.values, itr[Symbol.iterator],
           "IterableSingle: Should be using @@iterator for 'values'");
+       is(itr.forEach, Array.prototype.forEach,
+          "IterableSingle: Should be using %ArrayIterator% for 'forEach'");
        var keys = [...itr.keys()];
        var values = [...itr.values()];
        var entries = [...itr.entries()];
@@ -81,6 +84,23 @@
          is(entry.value[1], entries[i][1],
             "IterableSingle: Entry iterator value 1 should match destructuring " + i);
        }
+
+       var callsToForEachCallback = 0;
+       var thisArg = {};
+       itr.forEach(function(value, index, obj) {
+         is(index, callsToForEachCallback,
+            `IterableSingle: Should have the right index at ${callsToForEachCallback} calls to forEach callback`);
+         is(value, values[index],
+            `IterableSingle: Should have the right value at ${callsToForEachCallback} calls to forEach callback`);
+         is(this, thisArg,
+            "IterableSingle: Should have the right this value for forEach callback");
+         is(obj, itr,
+            "IterableSingle: Should have the right third arg for forEach callback");
+         ++callsToForEachCallback;
+       }, thisArg);
+       is(callsToForEachCallback, 3,
+          "IterableSingle: Should have right total number of calls to forEach callback");
+
        var key = key_itr.next();
        var value = value_itr.next();
        var entry = entries_itr.next();
@@ -124,6 +144,23 @@
          is(entry.value[1], entries[i][1],
             "IterableDouble: Entry iterator value 1 should match destructuring " + i);
        }
+
+       callsToForEachCallback = 0;
+       thisArg = {};
+       itr.forEach(function(value, key, obj) {
+         is(key, keys[callsToForEachCallback],
+            `IterableDouble: Should have the right key at ${callsToForEachCallback} calls to forEach callback`);
+         is(value, values[callsToForEachCallback],
+            `IterableDouble: Should have the right value at ${callsToForEachCallback} calls to forEach callback`);
+         is(this, thisArg,
+            "IterableDouble: Should have the right this value for forEach callback");
+         is(obj, itr,
+            "IterableSingle: Should have the right third arg for forEach callback");
+         ++callsToForEachCallback;
+       }, thisArg);
+       is(callsToForEachCallback, 3,
+          "IterableDouble: Should have right total number of calls to forEach callback");
+
        var key = key_itr.next();
        var value = value_itr.next();
        var entry = entries_itr.next()