opentofu/terraform/graph_walk.go
James Bardin 0b025d74e5 add EvalContext.WithPath
As the Graph is walked, the current way to set the context path was to
have the walker return a context from EnterPath. This required that
every node know it's absolute path, which can no longer be the case
during plan when modules have not been expanded.

This introduces a new method called WithPath, which returns a copy of
the context with the internal path updated to reflect the method
argument. Any use of the EvalContext that requires knowing the path will
now panic if it wasn't explicitly set to ensure that evaluations always
occur in the correct path.

Add EvalContext to the GraphWalker interface.
EvalContext returns an EvalContext that has not yet set a path. This
will allow us to enforce that all context operations requiring a module
instance path will require that a path be explicitly set rather than
evaluating within the wrong path.
2020-03-25 17:03:06 -04:00

35 lines
1.4 KiB
Go

package terraform
import (
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/tfdiags"
)
// GraphWalker is an interface that can be implemented that when used
// with Graph.Walk will invoke the given callbacks under certain events.
type GraphWalker interface {
EvalContext() EvalContext
EnterPath(addrs.ModuleInstance) EvalContext
ExitPath(addrs.ModuleInstance)
EnterVertex(dag.Vertex)
ExitVertex(dag.Vertex, tfdiags.Diagnostics)
EnterEvalTree(dag.Vertex, EvalNode) EvalNode
ExitEvalTree(dag.Vertex, interface{}, error) tfdiags.Diagnostics
}
// NullGraphWalker is a GraphWalker implementation that does nothing.
// This can be embedded within other GraphWalker implementations for easily
// implementing all the required functions.
type NullGraphWalker struct{}
func (NullGraphWalker) EvalContext() EvalContext { return new(MockEvalContext) }
func (NullGraphWalker) EnterPath(addrs.ModuleInstance) EvalContext { return new(MockEvalContext) }
func (NullGraphWalker) ExitPath(addrs.ModuleInstance) {}
func (NullGraphWalker) EnterVertex(dag.Vertex) {}
func (NullGraphWalker) ExitVertex(dag.Vertex, tfdiags.Diagnostics) {}
func (NullGraphWalker) EnterEvalTree(v dag.Vertex, n EvalNode) EvalNode { return n }
func (NullGraphWalker) ExitEvalTree(dag.Vertex, interface{}, error) tfdiags.Diagnostics {
return nil
}