Subject: RE: Default value for resultProvenance.lastDetectionTimeUtc is tricky: deferred
We actually had this problem of “what is the run’s start time” even before we amended the draft to introduce lastDetectionTimeUtc and its default value. Notice what the change draft said about firstDetectionTime:
It SHOULD specify the start time of the run in which the result was first detected, as opposed to, for example, the time within the run at which the result was actually generated.
NOTE: Using the run’s start time makes it possible to group together results that were first detected in the same run.
So somehow we need to say what we mean by “run start time”, for instance, with Option 1 or Option 2 below.
The default value logic for resultProvenance.lastDetectionTimeUtc is trickier than we imagined when we discussed it in TC #27. For now, I will not specify a default in the provisional draft. I added an agenda item to revisit it in TC #28.
In TC #27, we agreed to amend the change draft for Issue #272 (“Introduce resultProvenance object”) by adding lastDetectionTimeUtc, and defaulting it to the start time of the current run. When I started writing, a couple of complications emerged:
If the level property (§3.21.7) of the containing result object (§3.21) has any value except "pass" or "notApplicable", and if the startTimeUtc property (§???) of the containing run object (§3.12) is present, then lastDetectionTimeUtc shall default to the value of that startTimeUtc property.
First of all, we shouldn’t consider a result in the current run to constitute a “detection” unless the problem really was detected in this run. We didn’t consider that during TC #27.
Second – the run object doesn’t have a startTimeUtc property! That property is on the invocation object, and a run can have an array of invocations. The SARIF consumer won’t know which invocation’s start time to use for the default.
There are a few possibilities:
Note that even if we chose Option 2 or Option 3, resultProvenance.invocationIndex would still be useful. We just wouldn’t use it to calculate the default for lastDetectionTimeUtc.