[Intl] Add "position" to the return of next()

Add position to the return of %SegmentIterator%.next()
which newly added to the spec in
https://github.com/tc39/proposal-intl-segmenter/pull/42

Bug: v8:8305
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I8de7102acb670a6c529ab3e35601c78a8dc7703c
Reviewed-on: https://chromium-review.googlesource.com/c/1278636Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56963}

src/objects/js-segment-iterator.cc

@@ -143,33 +143,6 @@ Handle<Object> JSSegmentIterator::Position(
   return isolate->factory()->NewNumberFromInt(icu_break_iterator->current());
 }
 
-namespace {
-
-Handle<JSReceiver> CreateResultForNext(Isolate* isolate, Handle<String> segment,
-                                       Handle<Object> break_type) {
-  Factory* factory = isolate->factory();
-  // Step 10-13 of %SegmentIteratorPrototype%.next( )
-  // ecma402 #sec-segment-iterator-prototype-next
-  // 10. Let result be ! ObjectCreate(%ObjectPrototype%).
-  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
-
-  // 11. Perform ! CreateDataProperty(result "segment", segment).
-  CHECK(JSReceiver::CreateDataProperty(
-            isolate, result, factory->segment_string(), segment, kDontThrow)
-            .FromJust());
-
-  // 12. Perform ! CreateDataProperty(result, "breakType", breakType).
-  CHECK(JSReceiver::CreateDataProperty(isolate, result,
-                                       factory->breakType_string(), break_type,
-                                       kDontThrow)
-            .FromJust());
-
-  // 13. Return CreateIterResultObject(result, false).
-  return factory->NewJSIteratorResult(result, false);
-}
-
-}  // namespace
-
 // ecma402 #sec-segment-iterator-prototype-next
 MaybeHandle<JSReceiver> JSSegmentIterator::Next(
     Isolate* isolate, Handle<JSSegmentIterator> segment_iterator) {
@@ -185,6 +158,8 @@ MaybeHandle<JSReceiver> JSSegmentIterator::Next(
     return factory->NewJSIteratorResult(isolate->factory()->undefined_value(),
                                         true);
   }
+  // 6. Let newPosition be iterator.[[SegmentIteratorPosition]].
+  Handle<Object> new_position = factory->NewNumberFromInt(position);
 
   // 8. Let segment be the substring of string from previousPosition to
   // newPosition, inclusive of previousPosition and exclusive of newPosition.
@@ -192,8 +167,32 @@ MaybeHandle<JSReceiver> JSSegmentIterator::Next(
   ASSIGN_RETURN_ON_EXCEPTION(
       isolate, segment, segment_iterator->GetSegment(isolate, prev, position),
       JSReceiver);
+
+  // 9. Let breakType be iterator.[[SegmentIteratorBreakType]].
   Handle<Object> break_type = segment_iterator->BreakType();
-  return CreateResultForNext(isolate, segment, break_type);
+
+  // 10. Let result be ! ObjectCreate(%ObjectPrototype%).
+  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
+
+  // 11. Perform ! CreateDataProperty(result "segment", segment).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, result, factory->segment_string(), segment, kDontThrow)
+            .FromJust());
+
+  // 12. Perform ! CreateDataProperty(result, "breakType", breakType).
+  CHECK(JSReceiver::CreateDataProperty(isolate, result,
+                                       factory->breakType_string(), break_type,
+                                       kDontThrow)
+            .FromJust());
+
+  // 13. Perform ! CreateDataProperty(result, "position", newPosition).
+  CHECK(JSReceiver::CreateDataProperty(isolate, result,
+                                       factory->position_string(), new_position,
+                                       kDontThrow)
+            .FromJust());
+
+  // 14. Return CreateIterResultObject(result, false).
+  return factory->NewJSIteratorResult(result, false);
 }
 
 // ecma402 #sec-segment-iterator-prototype-following

test/intl/segmenter/segment-grapheme-next.js

@@ -25,12 +25,16 @@ for (const text of [
     ]) {
   const iter = seg.segment(text);
   let segments = [];
+  let oldPos = -1;
   for (let result = iter.next(); !result.done; result = iter.next()) {
     const v = result.value;
     assertEquals(undefined, v.breakType);
     assertEquals("string", typeof v.segment);
     assertTrue(v.segment.length > 0);
     segments.push(v.segment);
+    assertEquals("number", typeof v.position);
+    assertTrue(oldPos < v.position);
+    oldPos = v.position;
   }
   assertEquals(text, segments.join(''));
 }

test/intl/segmenter/segment-iterator-ownPropertyDescriptor.js

@@ -73,3 +73,19 @@ for (let rec of otherReceivers) {
    assertThrows(() => prototype.following.call(rec), TypeError);
    assertThrows(() => prototype.preceding.call(rec), TypeError);
 }
+
+// Check the property of the return object of next()
+let nextReturn = segmentIterator.next();
+
+function checkProperty(obj, property) {
+  let desc = Object.getOwnPropertyDescriptor(obj, property);
+  assertTrue(desc.writable);
+  assertTrue(desc.enumerable);
+  assertTrue(desc.configurable);
+}
+
+checkProperty(nextReturn, 'done');
+checkProperty(nextReturn, 'value');
+checkProperty(nextReturn.value, 'segment');
+checkProperty(nextReturn.value, 'breakType');
+checkProperty(nextReturn.value, 'position');

test/intl/segmenter/segment-line-next.js

@@ -25,12 +25,16 @@ for (const text of [
     ]) {
   const iter = seg.segment(text);
   let segments = [];
+  let oldPos = -1;
   for (let result = iter.next(); !result.done; result = iter.next()) {
     const v = result.value;
     assertTrue(["soft", "hard"].includes(iter.breakType), iter.breakType);
     assertEquals("string", typeof v.segment);
     assertTrue(v.segment.length > 0);
     segments.push(v.segment);
-   }
-   assertEquals(text, segments.join(''));
+    assertEquals("number", typeof v.position);
+    assertTrue(oldPos < v.position);
+    oldPos = v.position;
+  }
+  assertEquals(text, segments.join(''));
 }

test/intl/segmenter/segment-sentence-next.js

@@ -25,12 +25,16 @@ for (const text of [
     ]) {
   const iter = seg.segment(text);
   let segments = [];
+  let oldPos = -1;
   for (let result = iter.next(); !result.done; result = iter.next()) {
     const v = result.value;
     assertTrue(["sep", "term"].includes(iter.breakType), iter.breakType);
     assertEquals("string", typeof v.segment);
     assertTrue(v.segment.length > 0);
     segments.push(v.segment);
+    assertEquals("number", typeof v.position);
+    assertTrue(oldPos < v.position);
+    oldPos = v.position;
   }
   assertEquals(text, segments.join(''));
 }

test/intl/segmenter/segment-word-next.js

@@ -25,12 +25,16 @@ for (const text of [
     ]) {
   const iter = seg.segment(text);
   let segments = [];
+  let oldPos = -1;
   for (let result = iter.next(); !result.done; result = iter.next()) {
     const v = result.value;
     assertTrue(["word", "none"].includes(iter.breakType), iter.breakType);
     assertEquals("string", typeof v.segment);
     assertTrue(v.segment.length > 0);
     segments.push(v.segment);
+    assertEquals("number", typeof v.position);
+    assertTrue(oldPos < v.position);
+    oldPos = v.position;
   }
   assertEquals(text, segments.join(''));
 }