There are two important changes in this commit.
Constraints are now producing an error tuple. This error tuple
in turn can be provided to a function for formatting a human
readable error message. Both the error tuple and the formatting
code are controlled by and part of the constraint function.
Constraints now also implement the reverse operation.
When constraint functions only validate, the reverse operation
will be the same as the forward operation. When they also do
some conversion then the reverse operation will reverse it.
Since constraints are now performing 3 different operations
(forward, reverse and format_error), they now take the form
of a function accepting two separate arguments. The operation
is the first argument.
In addition, the return value was changed to take the form
of {ok, Value} | {error, Reason}. The value must be returned
as-is if it was not modified.
They are now cowboy:start_clear/3 and cowboy:start_tls/3.
The NumAcceptors argument can be specified via the
num_acceptor transport option. Ranch has been updated
to 1.4.0 to that effect.
This option allows customizing the compacting of the Req object
when using Websocket. By default it will keep most public fields
excluding headers of course, since those can be large.
The inactivity timeout is used to close the connection in the absence of
any data from the client.
Since this is not part or the rfc7540 spec, a new http2_SUITE module has
been created with a test for the inactivity_timeout.
This callback is called when an error occurs before the request
(including headers, excluding body) was fully received. The
init/3 callback will not be called. The callback receives the
partial Req object (possibly empty), the reason for the error
and the response command that the server will send. It allows
you to be aware of the error and possibly modify the response
before it is sent.
These tests cover frame sizes. It's mostly edge cases for sure
(ie misbehaving clients and us having to reject them properly).
I had these almost ready for a long time, so I'm glad I can
push them out.
This requires updating Cowlib too (we currently track master).
The Opts value is put last, to be more consistent with the
rest of the cowboy_req module.
Additionally a test handler was fixed which reduced the number
of errors in http_SUITE.
