HCL blocks vs kv maps is fragile

[philpennock]

Describe the bug
Trying to construct HCL which uses blocks, the output of yq in HCL mode is fragile as to whether the input strings contain certain characters.

Two input files, moved-simple.tf and moved-modules.tf

moved-simple.tf:

moved {
  from = "OLD"
  to   = "NEW"
}

moved-modules.tf:

moved {
  from = "module[\"OLD\"].foo"
  to   = "module[\"NEW\"].foo"
}

Using a command of yq -phcl -ojson | yq -pjson -ohcl to check round-tripping, we see some issues.

% yq < moved-simple.tf -phcl -ojson | yq -pjson -ohcl
moved {
  from = OLD
  to = NEW
}

% yq < moved-modules.tf -phcl -ojson | yq -pjson -ohcl
moved {
}
moved = {
  from = "module[\"OLD\"].foo"
  to = "module[\"NEW\"].foo"
}

You can see that in the simple case, we get a block output and round-trip fine. In the case which differs only in the string content of the data input, we no longer round-trip fine, and get both a block (empty) and a key/value assignment of an object.

---

Version of yq: v4.52.2
Operating system: linux
Installed via: go install

Additional context
Add any other context about the problem here.

I constructed some moved blocks from a terraform state pull, using xargs and shell echo. I had hoped to avoid the fragile shell and use yq instead but can't figure out how we signal when input is supposed to be block vs object assignment and can't make it reliable in the presence of the sort of strings encountered in a terraform state file.