Fault-tolerance

[giannifiore]

User Stories

As a web server developer,
I want the middleware to not cause my server to crash unexpectedly,
So that I can make sure the server tolerates Rebrandly downtimes and errors

Acceptance tests

[should tolerate unexpected failures and silently fallback to the basic flow]
Given a router ROUTER
Given that the middleware MW is installed on ROUTER,
Given that the middleware includes a bug causing it to halt,
Given a request REQ generally causing MW to be launched,
When request REQ is processed by ROUTER,
Then the exceptions generated in MW do not halt the global routing

[should tolerate bad tokens]
Given a router ROUTER,
Given that the middleware MW is installed on ROUTER,
Given that the authentication token for MW is wrong,
When router is created upon server launch,
Then MW would print a warning without causing the global router setup crash
Then MW would produce no effects (no-op) on the global routing

[should tolerate corrupted options]
Given a router ROUTER,
Given that the middleware MW is installed on ROUTER,
Given that the options for MW are not consistent with supported options,
When router is created upon server launch,
Then MW would print a warning without causing the global router setup crash
Then MW would produce no effects (no-op) on the global routing