stacks: allow unknown variables during apply operations

internal/stacks/stackruntime/apply_destroy_test.go

@@ -1025,6 +1025,139 @@ func TestApplyDestroy(t *testing.T) {
 				},
 			},
 		},
+		"destroy after manual removal": {
+			path: "removed-offline",
+			state: stackstate.NewStateBuilder().
+				AddComponentInstance(stackstate.NewComponentInstanceBuilder(mustAbsComponentInstance("component.parent")).
+					AddDependent(mustAbsComponent("component.child")).
+					AddOutputValue("value", cty.StringVal("hello"))).
+				AddResourceInstance(stackstate.NewResourceInstanceBuilder().
+					SetAddr(mustAbsResourceInstanceObject("component.parent.testing_resource.resource")).
+					SetProviderAddr(mustDefaultRootProvider("testing")).
+					SetResourceInstanceObjectSrc(states.ResourceInstanceObjectSrc{
+						AttrsJSON: mustMarshalJSONAttrs(map[string]interface{}{
+							"id":    "parent",
+							"value": "hello",
+						}),
+						Status: states.ObjectReady,
+					})).
+				AddComponentInstance(stackstate.NewComponentInstanceBuilder(mustAbsComponentInstance("component.child")).
+					AddDependency(mustAbsComponent("component.parent")).
+					AddInputVariable("value", cty.StringVal("hello"))).
+				AddResourceInstance(stackstate.NewResourceInstanceBuilder().
+					SetAddr(mustAbsResourceInstanceObject("component.child.testing_resource.resource")).
+					SetProviderAddr(mustDefaultRootProvider("testing")).
+					SetResourceInstanceObjectSrc(states.ResourceInstanceObjectSrc{
+						AttrsJSON: mustMarshalJSONAttrs(map[string]interface{}{
+							"id":    "child",
+							"value": "hello",
+						}),
+						Status: states.ObjectReady,
+					})).
+				Build(),
+			store: stacks_testing_provider.NewResourceStoreBuilder().
+				AddResource("child", cty.ObjectVal(map[string]cty.Value{
+					"id":    cty.StringVal("child"),
+					"value": cty.StringVal("hello"),
+				})).Build(),
+			cycles: []TestCycle{
+				{
+					planMode: plans.DestroyMode,
+					wantPlannedChanges: []stackplan.PlannedChange{
+						&stackplan.PlannedChangeApplyable{
+							Applyable: true,
+						},
+						&stackplan.PlannedChangeComponentInstance{
+							Addr:               mustAbsComponentInstance("component.child"),
+							Action:             plans.Delete,
+							Mode:               plans.DestroyMode,
+							PlanComplete:       true,
+							PlanApplyable:      true,
+							RequiredComponents: collections.NewSet(mustAbsComponent("component.parent")),
+							PlannedInputValues: map[string]plans.DynamicValue{
+								"value": mustPlanDynamicValueDynamicType(cty.UnknownVal(cty.String)),
+							},
+							PlannedInputValueMarks: map[string][]cty.PathValueMarks{
+								"value": nil,
+							},
+							PlannedOutputValues: make(map[string]cty.Value),
+							PlannedCheckResults: &states.CheckResults{},
+							PlanTimestamp:       fakePlanTimestamp,
+						},
+						&stackplan.PlannedChangeResourceInstancePlanned{
+							ResourceInstanceObjectAddr: mustAbsResourceInstanceObject("component.child.testing_resource.resource"),
+							ChangeSrc: &plans.ResourceInstanceChangeSrc{
+								Addr:         mustAbsResourceInstance("testing_resource.resource"),
+								PrevRunAddr:  mustAbsResourceInstance("testing_resource.resource"),
+								ProviderAddr: mustDefaultRootProvider("testing"),
+								ChangeSrc: plans.ChangeSrc{
+									Action: plans.Delete,
+									Before: mustPlanDynamicValue(cty.ObjectVal(map[string]cty.Value{
+										"id":    cty.StringVal("child"),
+										"value": cty.StringVal("hello"),
+									})),
+									After: mustPlanDynamicValue(cty.NullVal(cty.Object(map[string]cty.Type{
+										"id":    cty.String,
+										"value": cty.String,
+									}))),
+								},
+							},
+							PriorStateSrc: &states.ResourceInstanceObjectSrc{
+								AttrsJSON: mustMarshalJSONAttrs(map[string]interface{}{
+									"id":    "child",
+									"value": "hello",
+								}),
+								Status:       states.ObjectReady,
+								Dependencies: make([]addrs.ConfigResource, 0),
+							},
+							ProviderConfigAddr: mustDefaultRootProvider("testing"),
+							Schema:             stacks_testing_provider.TestingResourceSchema,
+						},
+						&stackplan.PlannedChangeComponentInstance{
+							Addr:               mustAbsComponentInstance("component.parent"),
+							Action:             plans.Delete,
+							Mode:               plans.DestroyMode,
+							PlanComplete:       true,
+							PlanApplyable:      false,
+							PlannedInputValues: make(map[string]plans.DynamicValue),
+							PlannedOutputValues: map[string]cty.Value{
+								"value": cty.DynamicVal,
+							},
+							PlannedCheckResults: &states.CheckResults{},
+							PlanTimestamp:       fakePlanTimestamp,
+						},
+						&stackplan.PlannedChangeResourceInstancePlanned{
+							ResourceInstanceObjectAddr: mustAbsResourceInstanceObject("component.parent.testing_resource.resource"),
+							ProviderConfigAddr:         mustDefaultRootProvider("testing"),
+						},
+						&stackplan.PlannedChangeHeader{
+							TerraformVersion: version.SemVer,
+						},
+						&stackplan.PlannedChangePlannedTimestamp{
+							PlannedTimestamp: fakePlanTimestamp,
+						},
+					},
+					wantAppliedChanges: []stackstate.AppliedChange{
+						&stackstate.AppliedChangeComponentInstanceRemoved{
+							ComponentAddr:         mustAbsComponent("component.child"),
+							ComponentInstanceAddr: mustAbsComponentInstance("component.child"),
+						},
+						&stackstate.AppliedChangeResourceInstanceObject{
+							ResourceInstanceObjectAddr: mustAbsResourceInstanceObject("component.child.testing_resource.resource"),
+							ProviderConfigAddr:         mustDefaultRootProvider("testing"),
+						},
+						&stackstate.AppliedChangeComponentInstanceRemoved{
+							ComponentAddr:         mustAbsComponent("component.parent"),
+							ComponentInstanceAddr: mustAbsComponentInstance("component.parent"),
+						},
+						&stackstate.AppliedChangeResourceInstanceObject{
+							ResourceInstanceObjectAddr: mustAbsResourceInstanceObject("component.parent.testing_resource.resource"),
+							ProviderConfigAddr:         mustDefaultRootProvider("testing"),
+						},
+					},
+				},
+			},
+		},
 		"partial destroy recovery": {
 			path:        "component-chain",
 			description: "this test simulates a partial destroy recovery",

internal/stacks/stackruntime/apply_test.go

@@ -1463,7 +1463,11 @@ After applying this plan, Terraform will no longer manage these objects. You wil
 							ComponentInstanceAddr: mustAbsComponentInstance("component.main"),
 							Dependencies:          collections.NewSet(mustAbsComponent("component.self")),
 							OutputValues:          make(map[addrs.OutputValue]cty.Value),
-							InputVariables:        make(map[addrs.InputVariable]cty.Value),
+							InputVariables: map[addrs.InputVariable]cty.Value{
+								mustInputVariable("input"): cty.UnknownVal(cty.Map(cty.Object(map[string]cty.Type{
+									"output": cty.String,
+								}))),
+							},
 						},
 						&stackstate.AppliedChangeInputVariable{
 							Addr:  mustStackInputVariable("inputs"),
@@ -2358,7 +2362,10 @@ func TestApplyWithFailedComponent(t *testing.T) {
 			ComponentInstanceAddr: mustAbsComponentInstance("component.self"),
 			Dependencies:          collections.NewSet(mustAbsComponent("component.parent")),
 			OutputValues:          make(map[addrs.OutputValue]cty.Value),
-			InputVariables:        make(map[addrs.InputVariable]cty.Value),
+			InputVariables: map[addrs.InputVariable]cty.Value{
+				mustInputVariable("id"):    cty.NullVal(cty.String),
+				mustInputVariable("input"): cty.UnknownVal(cty.String),
+			},
 		},
 	}
 
@@ -3110,16 +3117,14 @@ func TestApplyWithChangedInputValues(t *testing.T) {
 
 	go Apply(ctx, &applyReq, &applyResp)
 	applyChanges, applyDiags := collectApplyOutput(applyChangesCh, diagsCh)
-	if len(applyDiags) != 1 {
-		t.Fatalf("expected exactly two diagnostics, got %s", applyDiags.ErrWithWarnings())
-	}
 
 	sort.SliceStable(applyDiags, diagnosticSortFunc(applyDiags))
 	expectDiagnosticsForTest(t, applyDiags,
 		expectDiagnostic(
 			tfdiags.Error,
 			"Inconsistent value for input variable during apply",
 			"The value for non-ephemeral input variable \"input\" was set to a different value during apply than was set during plan. Only ephemeral input variables can change between the plan and apply phases."),
+		expectDiagnostic(tfdiags.Error, "Invalid inputs for component", "Invalid input variable definition object: attribute \"input\": string required."),
 	)
 
 	wantChanges := []stackstate.AppliedChange{

internal/stacks/stackruntime/internal/stackeval/component_instance.go

@@ -96,18 +96,9 @@ func (c *ComponentInstance) CheckInputVariableValues(ctx context.Context, phase
 	// We actually checked the errors statically already, so we only care about
 	// the value here.
 	val, diags := EvalComponentInputVariables(ctx, varDecls, wantTy, defs, decl, phase, c)
-	if phase == ApplyPhase {
-		if !val.IsWhollyKnown() {
-			// We can't apply a configuration that has unknown values in it.
-			// This means an error has occured somewhere else, while gathering
-			// the input variables. We return a nil value here, whatever caused
-			// the error should have raised an error diagnostic separately.
-			return cty.NilVal, diags
-		}
-
-		// Note, that unknown values during the planning phase are totally fine.
+	if diags.HasErrors() {
+		return cty.NilVal, diags
 	}
-
 	return val, diags
 }
 

internal/stacks/stackruntime/internal/stackeval/input_variable.go

@@ -107,7 +107,7 @@ func (v *InputVariable) Value(ctx context.Context, phase EvalPhase) cty.Value {
 }
 
 func (v *InputVariable) CheckValue(ctx context.Context, phase EvalPhase) (cty.Value, tfdiags.Diagnostics) {
-	return withCtyDynamicValPlaceholder(doOnceWithDiags(
+	return doOnceWithDiags(
 		ctx, v.value.For(phase), v.main,
 		func(ctx context.Context) (cty.Value, tfdiags.Diagnostics) {
 			var diags tfdiags.Diagnostics
@@ -211,7 +211,7 @@ func (v *InputVariable) CheckValue(ctx context.Context, phase EvalPhase) (cty.Va
 				return cfg.markValue(val), diags
 			}
 		},
-	))
+	)
 }
 
 // ExprReferenceValue implements Referenceable.

internal/stacks/stackruntime/testdata/mainbundle/test/removed-offline/child/child.tf

@@ -0,0 +1,16 @@
+terraform {
+  required_providers {
+    testing = {
+      source  = "hashicorp/testing"
+      version = "0.1.0"
+    }
+  }
+}
+
+variable "value" {
+  type = string
+}
+
+resource "testing_resource" "resource" {
+  value = var.value
+}

internal/stacks/stackruntime/testdata/mainbundle/test/removed-offline/parent/parent.tf

@@ -0,0 +1,14 @@
+terraform {
+  required_providers {
+    testing = {
+      source  = "hashicorp/testing"
+      version = "0.1.0"
+    }
+  }
+}
+
+resource "testing_resource" "resource" {}
+
+output "value" {
+  value = testing_resource.resource.id
+}

internal/stacks/stackruntime/testdata/mainbundle/test/removed-offline/removed-offline.tfstack.hcl

@@ -0,0 +1,28 @@
+required_providers {
+  testing = {
+    source  = "hashicorp/testing"
+    version = "0.1.0"
+  }
+}
+
+provider "testing" "default" {}
+
+component "parent" {
+  source = "./parent"
+
+  providers = {
+    testing = provider.testing.default
+  }
+}
+
+component "child" {
+  source = "./child"
+
+  providers = {
+    testing = provider.testing.default
+  }
+
+  inputs = {
+    value = component.parent.value
+  }
+}