* Add support for scoped resources
* refactor existing checks addrs and add check block addr
* Add configuration for check blocks
* introduce check blocks into the terraform node and transform graph
* address comments
* address comments
* don't execute checks during destroy operations
* don't even include check nodes for destroy operations
Ensure that empty check results are normalized in state serialization to
prevent unexpected state changes from being written.
Because there is no consistent empty, null and omit_empty usage for
state structs, there's no good way to create a test which will fail
for future additions.
Previously we were attempting to infer the checkable object address kind
of a given address by whether it included "output" in the position where
a resource type name would otherwise go.
That was already potentially risky because we've historically not
prevented a resource type named "output", and it's also a
forward-compatibility hazard in case we introduce additional object kinds
with entirely-new addressing schemes in future.
Given that, we'll instead always be explicit about what kind of address
we're storing in a wire or file format, so that we can make sure to always
use the intended parser when reading an address back into memory, or
return an error if we encounter a kind we're not familiar with.
This allows us to retain check results from one run into the next, so that
we can react to status changes between runs and potentially report e.g.
that a previously-failing check has now been fixed, or that a
previously-failing check is "still failing" so that an operator can get
a hint as to whether a problem is something they've just introduced or if
it was already an active problem before they made a change.
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.
If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
