Verify
Check that an intended result, invariant, deployment, or state transition is complete and correct, rather than assumed.
Identification
Diagnostic questions
- What constitutes success for this operation?
- How is that proven rather than assumed?
- How would drift from the intended state be detected?
- What evidence remains after the action is finished?
In practice
Verification is the practice with the widest reach across this catalog, which is why it is the default example. HA Light Controller compares the achieved state of a light with the commanded one. docmend verifies a completed run against the plan that produced it. Project Standards validates a repository against the packages it adopted and reports drift as a first-class result. Star Trek: Alter Course relies on determinism, which is verification applied to a whole simulated world.
The test of a verification step is whether it can fail. A check that passes because it is reading its own input has the shape of assurance and none of the content.
Background threads
Post-maintenance testing exists because a repair is a claim until it has been demonstrated. The same reasoning applies to a deployment, a migration, or a bulk edit: the work is not the change, it is the change plus the evidence that the change is what was intended.
Common failure
Verifying that the command was issued rather than that the state changed. The exit code is zero and nothing has actually happened.