LibWeb: Partially implement MediaSource.isTypeSupported()

Author: https://github.com/gmta
Commit: 24069d55bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2588
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/MediaSourceExtensions/MediaSource.cpp

@@ -8,6 +8,7 @@
 #include <LibWeb/Bindings/MediaSourcePrototype.h>
 #include <LibWeb/MediaSourceExtensions/EventNames.h>
 #include <LibWeb/MediaSourceExtensions/MediaSource.h>
+#include <LibWeb/MimeSniff/MimeType.h>
 
 namespace Web::MediaSourceExtensions {
 
@@ -67,4 +68,28 @@ GC::Ptr<WebIDL::CallbackType> MediaSource::onsourceclose()
     return event_handler_attribute(EventNames::sourceclose);
 }
 
+// https://w3c.github.io/media-source/#dom-mediasource-istypesupported
+bool MediaSource::is_type_supported(JS::VM&, String const& type)
+{
+    // 1. If type is an empty string, then return false.
+    if (type.is_empty())
+        return false;
+
+    // 2. If type does not contain a valid MIME type string, then return false.
+    auto mime_type = MimeSniff::MimeType::parse(type);
+    if (!mime_type.has_value())
+        return false;
+
+    // FIXME: 3. If type contains a media type or media subtype that the MediaSource does not support, then
+    //    return false.
+
+    // FIXME: 4. If type contains a codec that the MediaSource does not support, then return false.
+
+    // FIXME: 5. If the MediaSource does not support the specified combination of media type, media
+    //    subtype, and codecs then return false.
+
+    // 6. Return true.
+    return true;
+}
+
 }