google / exposure-notifications-verification-server

At present, VerificationCode.Validate returns an error for user error (e.g. invalid symptom onset date) and system error (e.g. code too short).

We need to separate these out because, upstream, it's impossible to determine if we should return a 4xx or 5xx response. Gorm also swallows the concrete error types, so we can't switch on them. However, even if we could, things like checking valid test type already exist in the controller.

/cc @mikehelmick

@whaught for you to consider in your refactor

/assign

We wind up checking most things twice (which is weird) and don't expect .BeforeSave() to fire. The test-too-old for example is checked here for client error:

exposure-notifications-verification-server/pkg/controller/issueapi/parse_date.go

Line 76 in d29ee06

} else if minDate.After(date) {

and then again here:

exposure-notifications-verification-server/pkg/database/vercode.go

Line 235 in 494b99e

minSymptomDate := timeutils.UTCMidnight(now.Add(-1 * maxAge))

Yea, I think we should explore moving all of this into the model if possible.

Refactor VerificationCode.Validate to separate user error from system error