core: Call into refactoring.ValidateMoves after creating a plan

As of this commit, refactoring.ValidateMoves doesn't actually do anything
yet (always returns nil) but the goal here is to wire in the set of all
declared instances so that refactoring.ValidateMoves will then have all
of the information it needs to encapsulate our validation rules.

The actual implementation of refactoring.ValidateMoves will follow in
subsequent commits.

internal/refactoring/move_validate.go

@@ -24,7 +24,7 @@ import (
 // construct in incorrect plan (because it'll be starting from the wrong
 // prior state) but ValidateMoves will block actually showing that invalid
 // plan to the user.
-func ValidateMoves(stmts []MoveStatement, rootCfg *configs.Config, expander *instances.Expander) tfdiags.Diagnostics {
+func ValidateMoves(stmts []MoveStatement, rootCfg *configs.Config, declaredInsts instances.Set) tfdiags.Diagnostics {
 	var diags tfdiags.Diagnostics
 
 	g := buildMoveStatementGraph(stmts)

internal/terraform/context.go

@@ -609,33 +609,6 @@ The -target option is not for routine use, and is provided only for exceptional
 		))
 	}
 
-	moveStmts := refactoring.FindMoveStatements(c.config)
-	if len(moveStmts) != 0 {
-		// TEMP: we haven't fully implemented moving yet, so we'll just
-		// reject it outright for now to reduce confusion.
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Moves are not yet supported",
-			"There is currently no handling of \"moved\" blocks in the configuration.",
-		))
-	}
-	moveResults := refactoring.ApplyMoves(moveStmts, c.prevRunState)
-	if len(c.targets) > 0 {
-		for _, result := range moveResults {
-			matchesTarget := false
-			for _, targetAddr := range c.targets {
-				if targetAddr.TargetContains(result.From) {
-					matchesTarget = true
-					break
-				}
-			}
-			if !matchesTarget {
-				// TODO: Return an error stating that a targeted plan is
-				// only valid if it includes this address that was moved.
-			}
-		}
-	}
-
 	var plan *plans.Plan
 	var planDiags tfdiags.Diagnostics
 	switch c.planMode {
@@ -653,10 +626,6 @@ The -target option is not for routine use, and is provided only for exceptional
 		return nil, diags
 	}
 
-	// TODO: Call refactoring.ValidateMoves, but need to figure out how to
-	// get hold of the plan's expander here, or somehow otherwise export
-	// the necessary subset of its data for ValidateMoves to do its work.
-
 	// convert the variables into the format expected for the plan
 	varVals := make(map[string]plans.DynamicValue, len(c.variables))
 	for k, iv := range c.variables {
@@ -687,6 +656,8 @@ The -target option is not for routine use, and is provided only for exceptional
 func (c *Context) plan() (*plans.Plan, tfdiags.Diagnostics) {
 	var diags tfdiags.Diagnostics
 
+	moveStmts, _ := c.prePlanFindAndApplyMoves()
+
 	graph, graphDiags := c.Graph(GraphTypePlan, nil)
 	diags = diags.Append(graphDiags)
 	if graphDiags.HasErrors() {
@@ -716,6 +687,9 @@ func (c *Context) plan() (*plans.Plan, tfdiags.Diagnostics) {
 	// to Apply work as expected.
 	c.state = refreshedState
 
+	// TODO: Record the move results in the plan
+	diags = diags.Append(c.postPlanValidateMoves(moveStmts, walker.InstanceExpander.AllInstances()))
+
 	return plan, diags
 }
 
@@ -726,6 +700,8 @@ func (c *Context) destroyPlan() (*plans.Plan, tfdiags.Diagnostics) {
 	}
 	c.changes = plans.NewChanges()
 
+	moveStmts, _ := c.prePlanFindAndApplyMoves()
+
 	// A destroy plan starts by running Refresh to read any pending data
 	// sources, and remove missing managed resources. This is required because
 	// a "destroy plan" is only creating delete changes, and is essentially a
@@ -778,12 +754,18 @@ func (c *Context) destroyPlan() (*plans.Plan, tfdiags.Diagnostics) {
 
 	destroyPlan.UIMode = plans.DestroyMode
 	destroyPlan.Changes = c.changes
+
+	// TODO: Record the move results in the plan
+	diags = diags.Append(c.postPlanValidateMoves(moveStmts, walker.InstanceExpander.AllInstances()))
+
 	return destroyPlan, diags
 }
 
 func (c *Context) refreshOnlyPlan() (*plans.Plan, tfdiags.Diagnostics) {
 	var diags tfdiags.Diagnostics
 
+	moveStmts, _ := c.prePlanFindAndApplyMoves()
+
 	graph, graphDiags := c.Graph(GraphTypePlanRefreshOnly, nil)
 	diags = diags.Append(graphDiags)
 	if graphDiags.HasErrors() {
@@ -834,9 +816,37 @@ func (c *Context) refreshOnlyPlan() (*plans.Plan, tfdiags.Diagnostics) {
 	// mutate
 	c.state = refreshedState
 
+	// TODO: Record the move results in the plan
+	diags = diags.Append(c.postPlanValidateMoves(moveStmts, walker.InstanceExpander.AllInstances()))
+
 	return plan, diags
 }
 
+func (c *Context) prePlanFindAndApplyMoves() ([]refactoring.MoveStatement, map[addrs.UniqueKey]refactoring.MoveResult) {
+	moveStmts := refactoring.FindMoveStatements(c.config)
+	moveResults := refactoring.ApplyMoves(moveStmts, c.prevRunState)
+	if len(c.targets) > 0 {
+		for _, result := range moveResults {
+			matchesTarget := false
+			for _, targetAddr := range c.targets {
+				if targetAddr.TargetContains(result.From) {
+					matchesTarget = true
+					break
+				}
+			}
+			if !matchesTarget {
+				// TODO: Return an error stating that a targeted plan is
+				// only valid if it includes this address that was moved.
+			}
+		}
+	}
+	return moveStmts, moveResults
+}
+
+func (c *Context) postPlanValidateMoves(stmts []refactoring.MoveStatement, allInsts instances.Set) tfdiags.Diagnostics {
+	return refactoring.ValidateMoves(stmts, c.config, allInsts)
+}
+
 // Refresh goes through all the resources in the state and refreshes them
 // to their latest state. This is done by executing a plan, and retaining the
 // state while discarding the change set.