Fixes#18822
The `tuncatedId` function had been introduced in #12261 and increased the
`maxIdLen` to 80 in #13317. Since the number of bytes itself seems to be
unimportant, the ID should be truncated to 80 characters, not 80 bytes.
We used to treat the "id" attribute of a resource as special and elevate
it into its own struct field "ID" in the state, but the new state format
and provider protocol treats it just as any other attribute.
However, it's still useful to show the value of a single identifying
attribute when there isn't room in the UI for showing all of the
attributes, and so here we take a new strategy of considering "id" along
with some other conventional names as special only in the UI layer.
This new heuristic approach can be adjusted over time as new provider
patterns emerge, but for now it covers some common conventions we've seen
in real providers.
With that said, since all existing providers made for Terraform versions
prior to v0.12 were forced to set "id", we won't see any use of other
attributes here until providers are updated to remove the placeholder
ids they were generating in cases where an id was not actually relevant
but was forced by the old protocol. At that point the UX should be
improved by showing a more relevant attribute instead.
We now also allow for the possibility of no id at all, since that is valid
for resources that exist only within the Terraform state, like the ones
from the "random" and "tls" providers.
Due to how often the state and plan types are referenced throughout
Terraform, there isn't a great way to switch them out gradually. As a
consequence, this huge commit gets us from the old world to a _compilable_
new world, but still has a large number of known test failures due to
key functionality being stubbed out.
The stubs here are for anything that interacts with providers, since we
now need to do the follow-up work to similarly replace the old
terraform.ResourceProvider interface with its replacement in the new
"providers" package. That work, along with work to fix the remaining
failing tests, will follow in subsequent commits.
The aim here was to replace all references to terraform.State and its
downstream types with states.State, terraform.Plan with plans.Plan,
state.State with statemgr.State, and switch to the new implementations of
the state and plan file formats. However, due to the number of times those
types are used, this also ended up affecting numerous other parts of core
such as terraform.Hook, the backend.Backend interface, and most of the CLI
commands.
Just as with 5861dbf3fc49b19587a31816eb06f511ab861bb4 before, I apologize
in advance to the person who inevitably just found this huge commit while
spelunking through the commit history.
