Bug 1471165 - P1. Simulate required MediaCapabilities members in optional dictionary. r=bz

Summary:
In order to allow for optional dictionaries with required members
See https://github.com/heycam/webidl/issues/76 for more information.

Reviewers: bzbarsky

Tags: #secure-revision

Bug #: 1471165

Differential Revision: https://phabricator.services.mozilla.com/D1833

dom/media/MediaMIMETypes.cpp

@@ -262,10 +262,16 @@ MakeMediaExtendedMIMEType(const nsAString& aType)
 Maybe<MediaExtendedMIMEType>
 MakeMediaExtendedMIMEType(const dom::VideoConfiguration& aConfig)
 {
-  if (aConfig.mContentType.IsEmpty()) {
+  MOZ_ASSERT(aConfig.mContentType.WasPassed() &&
+             aConfig.mFramerate.WasPassed() &&
+             aConfig.mWidth.WasPassed() &&
+             aConfig.mHeight.WasPassed() &&
+             aConfig.mBitrate.WasPassed(),
+             "All dictionary members must be present");
+  if (aConfig.mContentType.Value().IsEmpty()) {
     return Nothing();
   }
-  nsContentTypeParser parser(aConfig.mContentType);
+  nsContentTypeParser parser(aConfig.mContentType.Value());
   nsAutoString mime;
   nsresult rv = parser.GetType(mime);
   if (!NS_SUCCEEDED(rv) || mime.IsEmpty()) {
@@ -282,28 +288,30 @@ MakeMediaExtendedMIMEType(const dom::VideoConfiguration& aConfig)
   bool haveCodecs = NS_SUCCEEDED(rv);
 
   auto framerate =
-    MediaExtendedMIMEType::ComputeFractionalString(aConfig.mFramerate);
+    MediaExtendedMIMEType::ComputeFractionalString(aConfig.mFramerate.Value());
   if (!framerate) {
     return Nothing();
   }
 
-  return Some(MediaExtendedMIMEType(NS_ConvertUTF16toUTF8(aConfig.mContentType),
+  return Some(
-                                    mime8,
+    MediaExtendedMIMEType(NS_ConvertUTF16toUTF8(aConfig.mContentType.Value()),
-                                    haveCodecs,
+                          mime8,
-                                    codecs,
+                          haveCodecs,
-                                    aConfig.mWidth,
+                          codecs,
-                                    aConfig.mHeight,
+                          aConfig.mWidth.Value(),
-                                    framerate.ref(),
+                          aConfig.mHeight.Value(),
-                                    aConfig.mBitrate));
+                          framerate.ref(),
+                          aConfig.mBitrate.Value()));
 }
 
 Maybe<MediaExtendedMIMEType>
 MakeMediaExtendedMIMEType(const dom::AudioConfiguration& aConfig)
 {
-  if (aConfig.mContentType.IsEmpty()) {
+  if (!aConfig.mContentType.WasPassed() ||
+      aConfig.mContentType.Value().IsEmpty()) {
     return Nothing();
   }
-  nsContentTypeParser parser(aConfig.mContentType);
+  nsContentTypeParser parser(aConfig.mContentType.Value());
   nsAutoString mime;
   nsresult rv = parser.GetType(mime);
   if (!NS_SUCCEEDED(rv) || mime.IsEmpty()) {
@@ -335,7 +343,7 @@ MakeMediaExtendedMIMEType(const dom::AudioConfiguration& aConfig)
   }
 
   return Some(MediaExtendedMIMEType(
-    NS_ConvertUTF16toUTF8(aConfig.mContentType),
+    NS_ConvertUTF16toUTF8(aConfig.mContentType.Value()),
     mime8,
     haveCodecs,
     codecs,

dom/media/mediacapabilities/MediaCapabilities.cpp

@@ -32,6 +32,54 @@ MediaCapabilities::MediaCapabilities(nsIGlobalObject* aParent)
 {
 }
 
+static void
+ThrowWithMemberName(ErrorResult& aRv,
+                    const char* aCategory,
+                    const char* aMember)
+{
+  auto str = nsPrintfCString("'%s' member of %s", aMember, aCategory);
+  aRv.ThrowTypeError<MSG_MISSING_REQUIRED_DICTIONARY_MEMBER>(
+    NS_ConvertUTF8toUTF16(str));
+}
+
+static void
+CheckVideoConfigurationSanity(const VideoConfiguration& aConfig,
+                              const char* aCategory,
+                              ErrorResult& aRv)
+{
+  if (!aConfig.mContentType.WasPassed()) {
+    ThrowWithMemberName(aRv, "contentType", aCategory);
+    return;
+  }
+  if (!aConfig.mWidth.WasPassed()) {
+    ThrowWithMemberName(aRv, "width", aCategory);
+    return;
+  }
+  if (!aConfig.mHeight.WasPassed()) {
+    ThrowWithMemberName(aRv, "height", aCategory);
+    return;
+  }
+  if (!aConfig.mBitrate.WasPassed()) {
+    ThrowWithMemberName(aRv, "bitrate", aCategory);
+    return;
+  }
+  if (!aConfig.mFramerate.WasPassed()) {
+    ThrowWithMemberName(aRv, "framerate", aCategory);
+    return;
+  }
+}
+
+static void
+CheckAudioConfigurationSanity(const AudioConfiguration& aConfig,
+                              const char* aCategory,
+                              ErrorResult& aRv)
+{
+  if (!aConfig.mContentType.WasPassed()) {
+    ThrowWithMemberName(aRv, "contentType", aCategory);
+    return;
+  }
+}
+
 already_AddRefed<Promise>
 MediaCapabilities::DecodingInfo(
   const MediaDecodingConfiguration& aConfiguration,
@@ -52,6 +100,25 @@ MediaCapabilities::DecodingInfo(
     return nullptr;
   }
 
+  // Here we will throw rather than rejecting a promise in order to simulate
+  // optional dictionaries with required members (see bug 1368949)
+  if (aConfiguration.mVideo.IsAnyMemberPresent()) {
+    // Check that all VideoConfiguration required members are present.
+    CheckVideoConfigurationSanity(
+      aConfiguration.mVideo, "MediaDecodingConfiguration", aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+  if (aConfiguration.mAudio.IsAnyMemberPresent()) {
+    // Check that all AudioConfiguration required members are present.
+    CheckAudioConfigurationSanity(
+      aConfiguration.mAudio, "MediaDecodingConfiguration", aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+
   bool supported = true;
   Maybe<MediaContainerType> videoContainer;
   Maybe<MediaContainerType> audioContainer;
@@ -68,8 +135,8 @@ MediaCapabilities::DecodingInfo(
     // We have a video configuration and it is valid. Check if it is supported.
     supported &=
       aConfiguration.mType == MediaDecodingType::File
-        ? CheckTypeForFile(aConfiguration.mVideo.mContentType)
+        ? CheckTypeForFile(aConfiguration.mVideo.mContentType.Value())
-        : CheckTypeForMediaSource(aConfiguration.mVideo.mContentType);
+        : CheckTypeForMediaSource(aConfiguration.mVideo.mContentType.Value());
   }
   if (aConfiguration.mAudio.IsAnyMemberPresent()) {
     audioContainer = CheckAudioConfiguration(aConfiguration.mAudio);
@@ -80,8 +147,8 @@ MediaCapabilities::DecodingInfo(
     // We have an audio configuration and it is valid. Check if it is supported.
     supported &=
       aConfiguration.mType == MediaDecodingType::File
-        ? CheckTypeForFile(aConfiguration.mAudio.mContentType)
+        ? CheckTypeForFile(aConfiguration.mAudio.mContentType.Value())
-        : CheckTypeForMediaSource(aConfiguration.mAudio.mContentType);
+        : CheckTypeForMediaSource(aConfiguration.mAudio.mContentType.Value());
   }
 
   if (!supported) {
@@ -323,6 +390,25 @@ MediaCapabilities::EncodingInfo(
     return nullptr;
   }
 
+  // Here we will throw rather than rejecting a promise in order to simulate
+  // optional dictionaries with required members (see bug 1368949)
+  if (aConfiguration.mVideo.IsAnyMemberPresent()) {
+    // Check that all VideoConfiguration required members are present.
+    CheckVideoConfigurationSanity(
+      aConfiguration.mVideo, "MediaDecodingConfiguration", aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+  if (aConfiguration.mAudio.IsAnyMemberPresent()) {
+    // Check that all AudioConfiguration required members are present.
+    CheckAudioConfigurationSanity(
+      aConfiguration.mAudio, "MediaDecodingConfiguration", aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+
   bool supported = true;
 
   // If configuration.video is present and is not a valid video configuration,
@@ -333,7 +419,8 @@ MediaCapabilities::EncodingInfo(
       return nullptr;
     }
     // We have a video configuration and it is valid. Check if it is supported.
-    supported &= CheckTypeForEncoder(aConfiguration.mVideo.mContentType);
+    supported &=
+      CheckTypeForEncoder(aConfiguration.mVideo.mContentType.Value());
   }
   if (aConfiguration.mAudio.IsAnyMemberPresent()) {
     if (!CheckAudioConfiguration(aConfiguration.mAudio)) {
@@ -341,7 +428,8 @@ MediaCapabilities::EncodingInfo(
       return nullptr;
     }
     // We have an audio configuration and it is valid. Check if it is supported.
-    supported &= CheckTypeForEncoder(aConfiguration.mAudio.mContentType);
+    supported &=
+      CheckTypeForEncoder(aConfiguration.mAudio.mContentType.Value());
   }
 
   auto info = MakeUnique<MediaCapabilitiesInfo>(supported, supported, false);

dom/webidl/MediaCapabilities.webidl

@@ -32,16 +32,22 @@ enum MediaEncodingType {
   "transmission"
 };
 
+// all members are specified as required in the spec.
+// We enforce that requirement in the MediaCapabilities code instead
+// See https://github.com/heycam/webidl/issues/76
 dictionary VideoConfiguration {
-  required DOMString contentType;
+  DOMString contentType;
-  required unsigned long width;
+  unsigned long width;
-  required unsigned long height;
+  unsigned long height;
-  required unsigned long long bitrate;
+  unsigned long long bitrate;
-  required DOMString framerate;
+  DOMString framerate;
 };
 
+// contentType member is specified as required in the spec.
+// We enforce that requirement in the MediaCapabilities code instead
+// See https://github.com/heycam/webidl/issues/76
 dictionary AudioConfiguration {
-  required DOMString contentType;
+  DOMString contentType;
   DOMString channels;
   unsigned long long bitrate;
   unsigned long samplerate;
@@ -57,8 +63,6 @@ interface MediaCapabilitiesInfo {
 
 [Exposed=(Window, Worker), Func="mozilla::dom::MediaCapabilities::Enabled"]
 interface MediaCapabilities {
-  // As per https://github.com/WICG/media-capabilities/issues/91 we mark the
-  // methods as always returning a new object.
   [NewObject]
   Promise<MediaCapabilitiesInfo> decodingInfo(MediaDecodingConfiguration configuration);
   [NewObject]