Backport of actions: improve error when action_trigger references unknown action into v1.14

internal/terraform/context_plan_actions_test.go

@@ -4088,8 +4088,41 @@ resource "test_object" "a" {
 	if !diags.HasErrors() {
 		t.Fatal("expected errors, got success!")
 	}
-	if diags.Err().Error() != "Configuration for triggered action does not exist: The configuration for the given action action.test_action.hello does not exist. All triggered actions must have an associated configuration." {
-		t.Fatal("wrong error!")
+	expectedErr := "action_trigger actions references non-existent action: The lifecycle action_trigger actions list contains a reference to the action \"action.test_action.hello\" that does not exist in the configuration of this module."
+	if diags.Err().Error() != expectedErr {
+		t.Fatalf("wrong error!, got %q, expected %q", diags.Err().Error(), expectedErr)
+	}
+}
+
+func TestContextPlan_validateActionInTriggerExistsWithSimilarAction(t *testing.T) {
+	// this validation occurs during TransformConfig
+	module := `
+action "test_action" "hello_word" {}
+
+resource "test_object" "a" {
+  lifecycle {
+    action_trigger {
+      events = [after_create]
+      actions = [action.test_action.hello_world]
+    }
+  }
+}
+`
+	m := testModuleInline(t, map[string]string{"main.tf": module})
+	p := simpleMockProvider()
+	ctx := testContext2(t, &ContextOpts{
+		Providers: map[addrs.Provider]providers.Factory{
+			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
+		},
+	})
+
+	_, diags := ctx.Plan(m, nil, DefaultPlanOpts)
+	if !diags.HasErrors() {
+		t.Fatal("expected errors, got success!")
+	}
+	expectedErr := "action_trigger actions references non-existent action: The lifecycle action_trigger actions list contains a reference to the action \"action.test_action.hello_world\" that does not exist in the configuration of this module. Did you mean \"action.test_action.hello_word\"?"
+	if diags.Err().Error() != expectedErr {
+		t.Fatalf("wrong error!, got %q, expected %q", diags.Err().Error(), expectedErr)
 	}
 }
 

internal/terraform/transform_config.go

@@ -6,12 +6,15 @@ package terraform
 import (
 	"fmt"
 	"log"
+	"maps"
+	"slices"
 
 	"github.com/hashicorp/hcl/v2"
 
 	"github.com/hashicorp/terraform/internal/addrs"
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/dag"
+	"github.com/hashicorp/terraform/internal/didyoumean"
 	"github.com/hashicorp/terraform/internal/lang/langrefs"
 	"github.com/hashicorp/terraform/internal/tfdiags"
 )
@@ -164,7 +167,7 @@ func (t *ConfigTransformer) transformSingle(g *Graph, config *configs.Config) er
 		// Verify that any actions referenced in the resource's ActionTriggers exist in this module
 		var diags tfdiags.Diagnostics
 		if r.Managed != nil && r.Managed.ActionTriggers != nil {
-			for i, at := range r.Managed.ActionTriggers {
+			for _, at := range r.Managed.ActionTriggers {
 				for _, action := range at.Actions {
 
 					refs, parseRefDiags := langrefs.ReferencesInExpr(addrs.ParseRef, action.Expr)
@@ -190,11 +193,17 @@ func (t *ConfigTransformer) transformSingle(g *Graph, config *configs.Config) er
 
 					_, ok := allConfigActions[configAction.String()]
 					if !ok {
+						suggestion := didyoumean.NameSuggestion(configAction.String(), slices.Collect(maps.Keys(allConfigActions)))
+						if suggestion != "" {
+							suggestion = fmt.Sprintf(" Did you mean %q?", suggestion)
+						}
+
 						diags = diags.Append(&hcl.Diagnostic{
 							Severity: hcl.DiagError,
-							Summary:  "Configuration for triggered action does not exist",
-							Detail:   fmt.Sprintf("The configuration for the given action %s does not exist. All triggered actions must have an associated configuration.", configAction.String()),
-							Subject:  &r.Managed.ActionTriggers[i].DeclRange,
+							Summary:  "action_trigger actions references non-existent action",
+							Detail:   fmt.Sprintf("The lifecycle action_trigger actions list contains a reference to the action %q that does not exist in the configuration of this module.%s", configAction.String(), suggestion),
+							Subject:  action.Expr.Range().Ptr(),
+							Context:  r.DeclRange.Ptr(),
 						})
 					}
 				}