While the returned plan is checked for nil in most cases, there was
a single point where the plan was dereferenced which could panic. Rather
than always guarding the dereferences, return early when the plan is
nil.
This is an alternative way to set the CLI configuration setting
plugin_cache_may_break_dependency_lock_file to activate the transitional
compatibility behavior that prefers to break the dependency lock file if
that would create an additional opportunity to use the plugin cache.
This test case was making a real DNS call in a non-acceptance test, and
since it was intended to fail it would introduce a several second delay.
This commit replaces the test with a similar one which uses the mocked
disco services for a non-TFE host.
Also restructure the test to use t.Run for clarity.
This is a mostly mechanical refactor with a handful of changes which
are necessary due to the semantic difference between earlyconfig and
configs.
When parsing root and descendant modules in the module installer, we now
check the core version requirements inline. If the Terraform version is
incompatible, we drop any other module loader diagnostics. This ensures
that future language additions don't clutter the output and confuse the
user.
We also add two new checks during the module load process:
* Don't try to load a module with a `nil` source address. This is a
necessary change due to the move away from earlyconfig.
* Don't try to load a module with a blank name (i.e. `module ""`).
Because our module loading manifest uses the stringified module path
as its map key, this causes a collision with the root module, and a
later panic. This is the bug which triggered this refactor in the
first place.
Since it's already possible to activate the dependency lock file using an
environment variable, we should allow opting in to it having broken
behavior using the environment too.
It's kinda odd in retrospect that TF_PLUGIN_CACHE_DIR is the only setting
we allow to be configured both in the environment and the CLI
configuration. That means that the infrastructure for dealing with that
situation was relatively immature here and so I did some light refactoring
to make it unit-testable without actually modifying the test program's
environment.
* Add metadata functions doc to internals
* Add metadata functions to internals nav
* Review feedback
* Renamed the doc
* Fixed small typos
* Update page title
