terraform test crash when using module.source

[drewmullen]

Terraform Version

./tftest -version                                           
Terraform v1.6.0-alpha20230719
on darwin_arm64
+ provider registry.terraform.io/hashicorp/aws v5.9.0
+ provider registry.terraform.io/hashicorp/awscc v0.56.0

Terraform Configuration Files

run "validate_locals" {
  command = plan

  module {
    source = "./examples/public_private_flow_logs"
  }

  assert {
    condition = local.myval == "drew"
    error_message = "its not drew"
  }
}

Debug Output

./tftest test                       

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Terraform crashed! This is always indicative of a bug within Terraform.
Please report the crash with Terraform[1] so that we can fix this.

When reporting bugs, please include your terraform version, the stack trace
shown below, and any additional information which may help replicate the issue.

[1]: https://github.com/hashicorp/terraform/issues

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!

no expansion has been registered for module.test
goroutine 473 [running]:
runtime/debug.Stack()
        /Users/runner/hostedtoolcache/go/1.20.4/x64/src/runtime/debug/stack.go:24 +0x64
runtime/debug.PrintStack()
        /Users/runner/hostedtoolcache/go/1.20.4/x64/src/runtime/debug/stack.go:16 +0x1c
github.com/hashicorp/terraform/internal/logging.PanicHandler()
        /Users/runner/work/terraform/terraform/internal/logging/panic.go:58 +0x170
panic({0x1049bd780, 0x1400638a020})
        /Users/runner/hostedtoolcache/go/1.20.4/x64/src/runtime/panic.go:890 +0x258
github.com/hashicorp/terraform/internal/instances.(*expanderModule).moduleInstances(0x1400698fb00, {0x140008696d0, 0x4, 0x5}, {0x14001dee8f0, 0x0, 0x4}, 0x0)
        /Users/runner/work/terraform/terraform/internal/instances/expander.go:370 +0x22c
github.com/hashicorp/terraform/internal/instances.(*Expander).expandModule(0x245700?, {0x140008696d0?, 0x14001dee9d8?, 0x10260d1e8?}, 0xd8?)
        /Users/runner/work/terraform/terraform/internal/instances/expander.go:126 +0x108
github.com/hashicorp/terraform/internal/instances.(*Expander).ExpandModule(...)
        /Users/runner/work/terraform/terraform/internal/instances/expander.go:105
github.com/hashicorp/terraform/internal/terraform.(*nodeExpandModule).Execute(0x14005ffa210, {0x104ef0f58, 0x140024dc620}, 0xb0?)
        /Users/runner/work/terraform/terraform/internal/terraform/node_module_expand.go:112 +0x7c
github.com/hashicorp/terraform/internal/terraform.(*ContextGraphWalker).Execute(0x14004aa6240, {0x104ef0f58, 0x140024dc620}, {0x12e4b1820, 0x14005ffa210})
        /Users/runner/work/terraform/terraform/internal/terraform/graph_walk_context.go:143 +0xa8
github.com/hashicorp/terraform/internal/terraform.(*Graph).walk.func1({0x104c75340, 0x14005ffa210})
        /Users/runner/work/terraform/terraform/internal/terraform/graph.go:78 +0x238
github.com/hashicorp/terraform/internal/dag.(*Walker).walkVertex(0x1400277a180, {0x104c75340, 0x14005ffa210}, 0x14000f79d80)
        /Users/runner/work/terraform/terraform/internal/dag/walk.go:384 +0x2dc
created by github.com/hashicorp/terraform/internal/dag.(*Walker).Update
        /Users/runner/work/terraform/terraform/internal/dag/walk.go:307 +0xb7c

Expected Behavior

test should plan the root module located in ./examples/public_private_flow_logs then run assert statements against it

Actual Behavior

crash

Steps to Reproduce

$ git clone git@github.com:drewmullen/terraform-aws-vpc-1.git
$ cd terraform-aws-vpc-1
$ git checkout terraform-test-native
$ terraform init
$ terraform test 

Additional Context

im sure yall went back and forth on this but, initially i set source = "../examples/" since that is the relative path to my tests dir. Not saying you should change it but... that was my initial thought

References

No response

[drewmullen]

Note: I thought this might be due to the fact that the source i point at doesnt have the local defined (dont hate me, im just trying this feature out :D). However, i tried adding the local to that root and still get a crash

In case its helpful, heres the PR im using to track my various tests: aws-ia/terraform-aws-vpc#127

[drewmullen]

I also just noticed that the example dir has a module source pointing to the hashi registry, i tried changing that to relative path back to the root, same crash

module "vpc" {
  # source  = "aws-ia/vpc/aws"
  # version = ">= 4.2.0"
  source = "../.."

[liamcervante]

Hi @drewmullen, thanks for finding another bug!

I can confirm I can replicate this. From what I can tell the cause of this seems to be modules loaded from run blocks referencing child modules.

We'll get this fixed for the next prerelease!

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.