terraform test: override prevent_destroy meta attribute (#37364)

Author: Liam Cervante

.changes/v1.14/ENHANCEMENTS-20250723-141420.yaml

@@ -0,0 +1,5 @@
+kind: ENHANCEMENTS
+body: 'terraform test: ignore prevent_destroy attribute during when cleaning up tests"'
+time: 2025-07-23T14:14:20.602923+02:00
+custom:
+    Issue: "37364"

internal/command/test_test.go

@@ -393,6 +393,10 @@ func TestTest_Runs(t *testing.T) {
 			expectedOut: []string{"test_resource.two will be destroyed"},
 			code:        0,
 		},
+		"prevent-destroy": {
+			expectedOut: []string{"1 passed, 0 failed."},
+			code:        0,
+		},
 	}
 	for name, tc := range tcs {
 		t.Run(name, func(t *testing.T) {

internal/command/testdata/test/prevent-destroy/main.tf

@@ -0,0 +1,7 @@
+
+resource "test_resource" "resource" {
+  lifecycle {
+    // we should still be able to destroy this during tests.
+    prevent_destroy = true
+  }
+}

internal/command/testdata/test/prevent-destroy/main.tftest.hcl

@@ -0,0 +1,2 @@
+
+run "test" {}

internal/moduletest/graph/node_state_cleanup.go

@@ -130,10 +130,12 @@ func (n *NodeStateCleanup) destroy(ctx *EvalContext, runNode *NodeTestRun, waite
 	setVariables, _, _ := runNode.FilterVariablesToModule(variables)
 
 	planOpts := &terraform.PlanOpts{
-		Mode:              plans.DestroyMode,
-		SetVariables:      setVariables,
-		Overrides:         mocking.PackageOverrides(run.Config, file.Config, mocks),
-		ExternalProviders: providers,
+		Mode:                   plans.DestroyMode,
+		SetVariables:           setVariables,
+		Overrides:              mocking.PackageOverrides(run.Config, file.Config, mocks),
+		ExternalProviders:      providers,
+		SkipRefresh:            true,
+		OverridePreventDestroy: true,
 	}
 
 	tfCtx, _ := terraform.NewContext(n.opts.ContextOpts)

internal/terraform/context_plan.go

@@ -139,6 +139,12 @@ type PlanOpts struct {
 	// Query is a boolean that indicates whether the plan is being
 	// generated for a query operation.
 	Query bool
+
+	// OverridePreventDestroy will override any prevent_destroy attributes
+	// allowing Terraform to destroy resources even if the prevent_destroy
+	// attribute is set. This can only be set during a destroy plan, and should
+	// only be set during the test command.
+	OverridePreventDestroy bool
 }
 
 // Plan generates an execution plan by comparing the given configuration
@@ -513,6 +519,7 @@ func (c *Context) destroyPlan(config *configs.Config, prevRunState *states.State
 		refreshOpts := *opts
 		refreshOpts.Mode = plans.NormalMode
 		refreshOpts.PreDestroyRefresh = true
+		refreshOpts.OverridePreventDestroy = false
 
 		// FIXME: A normal plan is required here to refresh the state, because
 		// the state and configuration may not match during a destroy, and a
@@ -912,6 +919,10 @@ func (c *Context) planGraph(config *configs.Config, prevRunState *states.State,
 		externalProviderConfigs = opts.ExternalProviders
 	}
 
+	if opts != nil && opts.OverridePreventDestroy && opts.Mode != plans.DestroyMode {
+		panic("you can only set OverridePreventDestroy during destroy operations.")
+	}
+
 	switch mode := opts.Mode; mode {
 	case plans.NormalMode:
 		// In Normal mode we need to pay attention to import and removed blocks
@@ -969,6 +980,7 @@ func (c *Context) planGraph(config *configs.Config, prevRunState *states.State,
 			Operation:               walkPlanDestroy,
 			Overrides:               opts.Overrides,
 			SkipGraphValidation:     c.graphOpts.SkipGraphValidation,
+			overridePreventDestroy:  opts.OverridePreventDestroy,
 		}).Build(addrs.RootModuleInstance)
 		return graph, walkPlanDestroy, diags
 	default:

internal/terraform/graph_builder_plan.go

@@ -114,6 +114,11 @@ type PlanGraphBuilder struct {
 	// If true, the graph builder will generate a query plan instead of a
 	// normal plan. This is used for the "terraform query" command.
 	queryPlan bool
+
+	// overridePreventDestroy is only applicable during destroy operations, and
+	// allows Terraform to ignore the configuration attribute prevent_destroy
+	// to destroy resources regardless.
+	overridePreventDestroy bool
 }
 
 // See GraphBuilder
@@ -141,6 +146,10 @@ func (b *PlanGraphBuilder) Steps() []GraphTransformer {
 		panic("invalid plan operation: " + b.Operation.String())
 	}
 
+	if b.overridePreventDestroy && b.Operation != walkPlanDestroy {
+		panic("overridePreventDestroy can only be set during walkPlanDestroy operations")
+	}
+
 	steps := []GraphTransformer{
 		// Creates all the resources represented in the config
 		&ConfigTransformer{
@@ -336,6 +345,7 @@ func (b *PlanGraphBuilder) initDestroy() {
 	b.initPlan()
 
 	b.ConcreteResourceInstance = func(a *NodeAbstractResourceInstance) dag.Vertex {
+		a.overridePreventDestroy = b.overridePreventDestroy
 		return &NodePlanDestroyableResourceInstance{
 			NodeAbstractResourceInstance: a,
 			skipRefresh:                  b.skipRefresh,

internal/terraform/node_resource_abstract_instance.go

@@ -46,6 +46,11 @@ type NodeAbstractResourceInstance struct {
 
 	preDestroyRefresh bool
 
+	// overridePreventDestroy is set during test cleanup operations to allow
+	// tests to clean up any created infrastructure regardless of this setting
+	// in the configuration.
+	overridePreventDestroy bool
+
 	// During import (or query) we may generate configuration for a resource, which needs
 	// to be stored in the final change.
 	generatedConfigHCL string
@@ -185,7 +190,7 @@ func (n *NodeAbstractResourceInstance) checkPreventDestroy(change *plans.Resourc
 		return nil
 	}
 
-	preventDestroy := n.Config.Managed.PreventDestroy
+	preventDestroy := n.Config.Managed.PreventDestroy && !n.overridePreventDestroy
 
 	if (change.Action == plans.Delete || change.Action.IsReplace()) && preventDestroy {
 		var diags tfdiags.Diagnostics