An interesting thing I am observing, somewhat related to @Kevin’s earlier question about searching files, as today, I am also looking to search for files within a specific folder. In the documentation for search.Type (the enumeration of the types of searches we can perform), there is NO entry for "FILE"... only for "FOLDER".
However, search.create({type:'file', name:'name of filecabinet file.pdf'}) is working for me.
All to say, there is an undocumented, important search.Type value of "file" if indeed, we want to search for a file.