obsolete: explode if metadata contains invalid UTF-8 sequence (API)
The current metadata API can be a source of bugs since it forces callers to
process encoding conversion by themselves. So let's make it reject bad data
as a last ditch. I assume there's no metadata field which is supposed to store
arbitrary BLOB like transplant_source.
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}