[webnfc] NDEFMessageInit#records is required and should not be empty

NDEFMessageInit#records is the only field of the dictionary
NDEFMessageInit, it's required, and being empty makes no sense for
constructing an NDEFMessage object.

BUG=520391

Change-Id: I87fd3fae3bbbba449d9068c0992ded2080e435b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1983435
Commit-Queue: Leon Han <leon.han@intel.com>
Reviewed-by: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Cr-Commit-Position: refs/heads/master@{#728120}

third_party/blink/renderer/modules/nfc/ndef_message.cc

@@ -17,8 +17,17 @@ namespace blink {
 NDEFMessage* NDEFMessage::Create(const ExecutionContext* execution_context,
                                  const NDEFMessageInit* init,
                                  ExceptionState& exception_state) {
+  // https://w3c.github.io/web-nfc/#creating-ndef-message
+
+  // NDEFMessageInit#records is a required field.
+  DCHECK(init->hasRecords());
+  if (init->records().IsEmpty()) {
+    exception_state.ThrowTypeError(
+        "NDEFMessageInit#records being empty makes no sense.");
+    return nullptr;
+  }
+
   NDEFMessage* message = MakeGarbageCollected<NDEFMessage>();
-  if (init->hasRecords()) {
     for (const NDEFRecordInit* record_init : init->records()) {
       NDEFRecord* record =
           NDEFRecord::Create(execution_context, record_init, exception_state);
@@ -27,7 +36,6 @@ NDEFMessage* NDEFMessage::Create(const ExecutionContext* execution_context,
       DCHECK(record);
       message->records_.push_back(record);
     }
-  }
   return message;
 }
 
@@ -35,6 +43,7 @@ NDEFMessage* NDEFMessage::Create(const ExecutionContext* execution_context,
 NDEFMessage* NDEFMessage::Create(const ExecutionContext* execution_context,
                                  const NDEFMessageSource& source,
                                  ExceptionState& exception_state) {
+  // https://w3c.github.io/web-nfc/#creating-ndef-message
   if (source.IsString()) {
     NDEFMessage* message = MakeGarbageCollected<NDEFMessage>();
     message->records_.push_back(MakeGarbageCollected<NDEFRecord>(

third_party/blink/renderer/modules/nfc/ndef_message_init.idl

@@ -5,5 +5,5 @@
 // https://w3c.github.io/web-nfc/#dom-ndefmessageinit
 
 dictionary NDEFMessageInit {
-    sequence<NDEFRecordInit> records;
+    required sequence<NDEFRecordInit> records;
 };

third_party/blink/renderer/modules/nfc/ndef_writer.cc

@@ -66,7 +66,7 @@ ScriptPromise NDEFWriter::push(ScriptState* script_state,
     return ScriptPromise();
   }
 
-  // Step 10.10.1: Run "create NDEF message", if this throws an exception,
+  // Step 11.2: Run "create NDEF message", if this throws an exception,
   // reject p with that exception and abort these steps.
   NDEFMessage* ndef_message =
       NDEFMessage::Create(execution_context, push_message, exception_state);
@@ -74,12 +74,6 @@ ScriptPromise NDEFWriter::push(ScriptState* script_state,
     return ScriptPromise();
   }
 
-  // If NDEFMessage.records is empty, reject promise with TypeError
-  if (ndef_message->records().size() == 0) {
-    exception_state.ThrowTypeError("Empty NDEFMessage was provided.");
-    return ScriptPromise();
-  }
-
   auto message = device::mojom::blink::NDEFMessage::From(ndef_message);
   DCHECK(message);
 

third_party/blink/web_tests/external/wpt/web-nfc/NDEFMessage_constructor.https.html

@@ -12,10 +12,20 @@
   }, 'NDEFMessage constructor without init dict');
 
   test(() => {
-    const message = new NDEFMessage(null);
-    assert_equals(message.records.length, 0, 'empty records');
+    assert_throws(new TypeError, () => new NDEFMessage(null),
+        'NDEFMessageInit#records is a required field.');
   }, 'NDEFMessage constructor with null init dict');
 
+  test(() => {
+    assert_throws(new TypeError, () => new NDEFMessage({dummy_key: 'dummy_value'}),
+        'NDEFMessageInit#records is a required field.');
+  }, 'NDEFMessage constructor without NDEFMessageInit#records field');
+
+  test(() => {
+    assert_throws(new TypeError, () => new NDEFMessage({records: []}),
+        'NDEFMessageInit#records should not be empty.');
+  }, 'NDEFMessage constructor with NDEFMessageInit#records being empty');
+
   test(() => {
     const message = new NDEFMessage(
         createMessage([createTextRecord(test_text_data)]));

third_party/blink/web_tests/external/wpt/web-nfc/NDEFReadingEvent_constructor.https.html

@@ -11,6 +11,12 @@
     assert_throws(new TypeError, () => new NDEFReadingEvent('message'));
   }, 'NDEFReadingEvent constructor without init dict');
 
+  test(() => {
+    assert_throws(new TypeError, () => new NDEFReadingEvent('type',
+          {serialNumber: '', message: null}),
+        'NDEFMessageInit#records is a required field.');
+  }, 'NDEFReadingEvent constructor failed to construct its NDEFMessage');
+
   test(() => {
     const message = createMessage([createMimeRecordFromJson(test_buffer_data)]);
     const event = new NDEFReadingEvent('type', {serialNumber: null, message: message});
@@ -23,11 +29,6 @@
     assert_equals(event.serialNumber, '', 'serialNumber');
   }, 'NDEFReadingEvent constructor with serialNumber not present');
 
-  test(() => {
-    const event = new NDEFReadingEvent('type', {serialNumber: '', message: null});
-    assert_equals(0, event.message.records.length, 'no records');
-  }, 'NDEFReadingEvent constructor with null message');
-
   test(() => {
     const message = createMessage([createMimeRecord(test_buffer_data)]);
     const event = new NDEFReadingEvent('type', {serialNumber: '', message: message});