Feature Request: Support multiple expectations per endpoint (parity with Bypass expect/2)

[fishtreesugar]

The add API currently behaves like Bypass’s expect_once; we’d like an option that matches Bypass’s expect/2, allowing multiple expectations for the same endpoint.

[danschultzer]

I decided against having something like this as I want to encourage explicit testing. TestServer is built up around FIFO and this would break that assumption. If you need to test numerous times with the same response you can just do:

for _n <- 1..10 do
  TestServer.add("/", to: fn conn ->
    Plug.Conn.send_resp(conn, 200, "OK")
  end)
end

But I think the real need to have something like multiple expectations is to be able to just mock the response and not care about how many times it gets called to prevent race condition issues. In that case I would recommend against using any mock server at all and instead mock the boundary as detailed here: https://dashbit.co/blog/req-api-client-testing

The benefit of using TestServer is to ensure the HTTP connection works properly, e.g. if you must ensure HTTPS connection and such.