Provider Function

Add a provider-defined function to the HashiCorp scaffold that parses a composite ID string.

Setup

git clone https://github.com/hashicorp/terraform-provider-scaffolding-framework.git .
git checkout 3f9b7d20f49724d61ffaa28f5812c347b6a3e4a1
go mod tidy

Task

Part 1: Create the function

Create a new file for a parse_id provider-defined function. The function takes a composite ID string in the format "type:name" and returns just the name portion.

Implement the function.Function interface:

1. Metadata: Set the function name to parse_id
2. Definition: Define the function with:
   • Summary and Description strings
   • One input parameter (String) — the composite ID to parse (e.g. "resource:my-thing")
   • Return type: String (the extracted name portion)
3. Run: Implement the logic:
   • Read the input argument using req.Arguments.Get
   • Split the string on ":"
   • If the string does not contain exactly one colon (resulting in exactly 2 parts), return a function error using function.NewArgumentFuncError
   • Return the second part (the name) as the result using resp.Result.Set

Part 2: Register the function

Register the function in the provider by implementing the Functions method on the provider (implementing provider.ProviderWithFunctions).

Part 3: Write tests

Write tests for the function:

1. A unit test that directly constructs a function.RunRequest and calls Run:
   • Test a valid input like "resource:my-thing" returns "my-thing"
   • Test an invalid input like "nocolon" returns a function error
2. An acceptance test (if possible) that uses output "test" { value = provider::scaffolding::parse_id("resource:my-thing") } and verifies the output value

Ensure the project builds with go build ./....