String Inputs With Interpolation

String inputs reach modules with ${...} intact

Passing a string input that contains ${...} to a variable declared with a type other than string used to fail with Variables not allowed, because OpenTofu/Terraform parse those values as HCL expressions and read ${...} as an interpolation. Reading a JSON or YAML file into an input hit this whenever the file happened to contain that sequence:

inputs = {
  config = file("./config.json")
}

Terragrunt now escapes interpolation sequences in string inputs when the module declares the variable with a type that makes the value parse as HCL, so ${...} arrives as literal text instead of failing the run. Variables declared as string, and variables declared with no type at all, are read verbatim by OpenTofu/Terraform, and their values are still passed through untouched.