hcl/hcldec/variables.go
Martin Atkins 36446359d2 hcldec: Variables must visit deeply-nested specifications
Previously this implementation was doing only one level of recursion in
its walk, which gave the appearance of working until the
transform/container-type specs (DefaultSpec, TransformSpec, ...) were
introduced, creating the possibility of "same body children" being more
than one level away from the initial spec.

It's still correct to only process the schema and content once, because
ImpliedSchema is already collecting all of the requirements from the
"same body children", and so our content object will include everything
that the nested specs should need to analyze needed variables.
2018-05-24 12:11:53 -07:00

37 lines
1.1 KiB
Go

package hcldec
import (
"github.com/hashicorp/hcl2/hcl"
)
// Variables processes the given body with the given spec and returns a
// list of the variable traversals that would be required to decode
// the same pairing of body and spec.
//
// This can be used to conditionally populate the variables in the EvalContext
// passed to Decode, for applications where a static scope is insufficient.
//
// If the given body is not compliant with the given schema, the result may
// be incomplete, but that's assumed to be okay because the eventual call
// to Decode will produce error diagnostics anyway.
func Variables(body hcl.Body, spec Spec) []hcl.Traversal {
var vars []hcl.Traversal
schema := ImpliedSchema(spec)
content, _, _ := body.PartialContent(schema)
if vs, ok := spec.(specNeedingVariables); ok {
vars = append(vars, vs.variablesNeeded(content)...)
}
var visitFn visitFunc
visitFn = func(s Spec) {
if vs, ok := s.(specNeedingVariables); ok {
vars = append(vars, vs.variablesNeeded(content)...)
}
s.visitSameBodyChildren(visitFn)
}
spec.visitSameBodyChildren(visitFn)
return vars
}