Question regarding tus `OPTIONS` requests

[aradalvand]

Hi there. The tus specification includes support for an OPTIONS request, which can be used by clients to gather information about the server's capabilities, notably which extensions it supports.

Based on my testing, it looks like this library (tus-js-client) doesn't make use of that feature at all; it never sends a tus OPTIONS request — I initially mistook the automatic browser-initiated CORS preflight requests for tus OPTIONS, but they're not the same thing.

Is my observation true? And if so, why not? What's the point of the tus OPTIONS request if the official client library never even uses it? I'm a bit confused here.

Thank you.

[Acconut]

An OPTIONS request is not mandatory to perform a tus upload, especially if the client is configured to be aware of the server's capabilities, as is the case for tus-js-client. Performing an OPTIONS request before every upload would then just introduce additional overhead and delays before the upload can start.

That being said, I would be nice if tus-js-client included a method to fetch the server's capabilities via an OPTIONS request, so clients can retrieve it programmatically. But so far there has been little to no demand for this.