Backport of ensure actions don't break the graph in modules with no instances into v1.14

.changes/v1.14/BUG FIXES-20260123-103307.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: actions in modules without instances failed the plan graph
+time: 2026-01-23T10:33:07.244665+01:00
+custom:
+    Issue: "38089"

internal/terraform/context_apply_action_test.go

@@ -783,6 +783,32 @@ resource "test_object" "a" {
 			}},
 		},
 
+		"not triggered with no module instances": {
+			module: map[string]string{
+				"main.tf": `
+module "mod" {
+    count = 0
+    source = "./mod"
+}
+
+// an empty plan is not applyable so we have this extra resource here
+resource "test_object" "a" {} 
+`,
+				"mod/mod.tf": `
+action "action_example" "hello" {}
+resource "test_object" "a" {
+  lifecycle {
+    action_trigger {
+      events = [before_create]
+      actions = [action.action_example.hello]
+    }
+  }
+}
+`,
+			},
+			expectInvokeActionCalled: false,
+		},
+
 		"provider is within module": {
 			module: map[string]string{
 				"main.tf": `

internal/terraform/context_plan_actions_test.go

@@ -893,7 +893,16 @@ resource "test_object" "a" {
 						t.Fatalf("expected action addresses to be 'action.test_action.hello[\"a\"]' and 'action.test_action.hello[\"b\"]', got %v", actionAddrs)
 					}
 
-					// TODO: Test that action the triggering resource address is set correctly
+					for _, ai := range p.Changes.ActionInvocations {
+						at, ok := ai.ActionTrigger.(*plans.LifecycleActionTrigger)
+						if !ok {
+							t.Fatalf("expected action trigger to be a LifecycleActionTrigger, got %T", ai.ActionTrigger)
+						}
+
+						if !at.TriggeringResourceAddr.Equal(mustResourceInstanceAddr("test_object.a")) {
+							t.Fatalf("expected action to have triggering resource address 'test_object.a', but it is %s", at.TriggeringResourceAddr)
+						}
+					}
 				},
 			},
 
@@ -938,7 +947,16 @@ resource "test_object" "a" {
 						t.Fatalf("expected action addresses to be 'action.test_action.hello[0]' and 'action.test_action.hello[1]', got %v", actionAddrs)
 					}
 
-					// TODO: Test that action the triggering resource address is set correctly
+					for _, ai := range p.Changes.ActionInvocations {
+						at, ok := ai.ActionTrigger.(*plans.LifecycleActionTrigger)
+						if !ok {
+							t.Fatalf("expected action trigger to be a LifecycleActionTrigger, got %T", ai.ActionTrigger)
+						}
+
+						if !at.TriggeringResourceAddr.Equal(mustResourceInstanceAddr("test_object.a")) {
+							t.Fatalf("expected action to have triggering resource address 'test_object.a', but it is %s", at.TriggeringResourceAddr)
+						}
+					}
 				},
 			},
 
@@ -1048,7 +1066,23 @@ resource "test_object" "a" {
 						t.Fatalf("expected action addresses to be 'action.test_action.hello' and 'action.test_action.hello', got %v", actionAddrs)
 					}
 
-					// TODO: Test that action the triggering resource address is set correctly
+					actionTriggers := []plans.LifecycleActionTrigger{}
+					for _, ai := range p.Changes.ActionInvocations {
+						at, ok := ai.ActionTrigger.(*plans.LifecycleActionTrigger)
+						if !ok {
+							t.Fatalf("expected action trigger to be a LifecycleActionTrigger, got %T", ai.ActionTrigger)
+						}
+
+						actionTriggers = append(actionTriggers, *at)
+					}
+
+					if !actionTriggers[0].TriggeringResourceAddr.Resource.Resource.Equal(actionTriggers[1].TriggeringResourceAddr.Resource.Resource) {
+						t.Fatalf("expected both actions to have the same triggering resource address, but got %s and %s", actionTriggers[0].TriggeringResourceAddr, actionTriggers[1].TriggeringResourceAddr)
+					}
+
+					if actionTriggers[0].TriggeringResourceAddr.Resource.Key == actionTriggers[1].TriggeringResourceAddr.Resource.Key {
+						t.Fatalf("expected both actions to have different triggering resource instance keys, but got the same %s", actionTriggers[0].TriggeringResourceAddr.Resource.Key)
+					}
 				},
 			},
 			"expanded resource - expanded action": {
@@ -1093,7 +1127,23 @@ resource "test_object" "a" {
 						t.Fatalf("expected action addresses to be 'action.test_action.hello[0]' and 'action.test_action.hello[1]', got %v", actionAddrs)
 					}
 
-					// TODO: Test that action the triggering resource address is set correctly
+					actionTriggers := []plans.LifecycleActionTrigger{}
+					for _, ai := range p.Changes.ActionInvocations {
+						at, ok := ai.ActionTrigger.(*plans.LifecycleActionTrigger)
+						if !ok {
+							t.Fatalf("expected action trigger to be a LifecycleActionTrigger, got %T", ai.ActionTrigger)
+						}
+
+						actionTriggers = append(actionTriggers, *at)
+					}
+
+					if !actionTriggers[0].TriggeringResourceAddr.Resource.Resource.Equal(actionTriggers[1].TriggeringResourceAddr.Resource.Resource) {
+						t.Fatalf("expected both actions to have the same triggering resource address, but got %s and %s", actionTriggers[0].TriggeringResourceAddr, actionTriggers[1].TriggeringResourceAddr)
+					}
+
+					if actionTriggers[0].TriggeringResourceAddr.Resource.Key == actionTriggers[1].TriggeringResourceAddr.Resource.Key {
+						t.Fatalf("expected both actions to have different triggering resource instance keys, but got the same %s", actionTriggers[0].TriggeringResourceAddr.Resource.Key)
+					}
 				},
 			},
 
@@ -1699,6 +1749,82 @@ resource "other_object" "a" {
 				},
 			},
 
+			"not triggered if module is count=0": {
+				module: map[string]string{
+					"main.tf": `
+module "mod" {
+    count = 0
+    source = "./mod"
+}
+`,
+					"mod/mod.tf": `
+action "test_action" "hello" {}
+resource "other_object" "a" {
+  lifecycle {
+    action_trigger {
+      events = [before_create]
+      actions = [action.test_action.hello]
+    }
+  }
+}
+`,
+				},
+				expectPlanActionCalled: false,
+			},
+
+			"not triggered if for_each is empty": {
+				module: map[string]string{
+					"main.tf": `
+module "mod" {
+    for_each = toset([])
+    source = "./mod"
+}
+`,
+					"mod/mod.tf": `
+action "test_action" "hello" {}
+resource "other_object" "a" {
+  lifecycle {
+    action_trigger {
+      events = [before_create]
+      actions = [action.test_action.hello]
+    }
+  }
+}
+`,
+				},
+				expectPlanActionCalled: false,
+			},
+
+			"action declaration in module if module is count=0": {
+				module: map[string]string{
+					"main.tf": `
+module "mod" {
+    count = 0
+    source = "./mod"
+}
+`,
+					"mod/mod.tf": `
+action "test_action" "hello" {}
+`,
+				},
+				expectPlanActionCalled: false,
+			},
+
+			"action declaration in module if for_each is empty": {
+				module: map[string]string{
+					"main.tf": `
+module "mod" {
+    for_each = toset([])
+    source = "./mod"
+}
+`,
+					"mod/mod.tf": `
+action "test_action" "hello" {}
+`,
+				},
+				expectPlanActionCalled: false,
+			},
+
 			"provider is within module": {
 				module: map[string]string{
 					"main.tf": `

internal/terraform/node_action.go

@@ -55,7 +55,6 @@ func (n *nodeExpandActionDeclaration) DynamicExpand(ctx EvalContext) (*Graph, tf
 				resolvedProvider: n.ResolvedProvider,
 			})
 		}
-		addRootNodeToGraph(&g)
 	}
 
 	for _, module := range moduleInstances {
@@ -94,9 +93,8 @@ func (n *nodeExpandActionDeclaration) DynamicExpand(ctx EvalContext) (*Graph, tf
 
 			g.Add(&node)
 		}
-
-		addRootNodeToGraph(&g)
 	}
+	addRootNodeToGraph(&g)
 
 	return &g, diags
 }