fix: Align name and name_prefix validation with AWS API for aws_db_ev…

…ent_subscription

.changelog/38194.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/aws_db_event_subscription: Fix validation for `name` and `name_prefix`
+```

internal/service/rds/event_subscription.go

@@ -80,7 +80,7 @@ func resourceEventSubscription() *schema.Resource {
 				Computed:      true,
 				ForceNew:      true,
 				ConflictsWith: []string{names.AttrName},
-				ValidateFunc:  validEventSubscriptionName,
+				ValidateFunc:  validEventSubscriptionNamePrefix,
 			},
 			"sns_topic": {
 				Type:         schema.TypeString,

internal/service/rds/validate.go

@@ -5,15 +5,25 @@ package rds
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/YakDriver/regexache"
 )
 
 func validEventSubscriptionName(v interface{}, k string) (ws []string, errors []error) {
 	value := v.(string)
-	if !regexache.MustCompile(`^[0-9A-Za-z-]+$`).MatchString(value) {
+	if !regexache.MustCompile(`^[A-Za-z][0-9A-Za-z-]*$`).MatchString(value) {
 		errors = append(errors, fmt.Errorf(
-			"only alphanumeric characters and hyphens allowed in %q", k))
+			"only ASCII letters, digits, and hyphens allowed in %q, and it must begin with a letter", k))
+	}
+	// When using name prefix, the generated suffix will always end with a number, so this check is not relevant
+	if strings.HasSuffix(value, "-") {
+		errors = append(errors, fmt.Errorf(
+			"%q cannot end with a hyphen", k))
+	}
+	if strings.Contains(value, "--") {
+		errors = append(errors, fmt.Errorf(
+			"%q cannot contain two consecutive hyphens", k))
 	}
 	if len(value) > 255 {
 		errors = append(errors, fmt.Errorf(
@@ -22,6 +32,24 @@ func validEventSubscriptionName(v interface{}, k string) (ws []string, errors []
 	return
 }
 
+func validEventSubscriptionNamePrefix(v interface{}, k string) (ws []string, errors []error) {
+	value := v.(string)
+	if !regexache.MustCompile(`^[A-Za-z][0-9A-Za-z-]*$`).MatchString(value) {
+		errors = append(errors, fmt.Errorf(
+			"only ASCII letters, digits, and hyphens allowed in %q, and it must begin with a letter", k))
+	}
+	if strings.Contains(value, "--") {
+		errors = append(errors, fmt.Errorf(
+			"%q cannot contain two consecutive hyphens", k))
+	}
+	// When using name prefix, the limit must account for the generated suffix that is 26 characters long
+	if len(value) > 229 {
+		errors = append(errors, fmt.Errorf(
+			"%q cannot be longer than 229 characters", k))
+	}
+	return
+}
+
 func validOptionGroupName(v interface{}, k string) (ws []string, errors []error) {
 	value := v.(string)
 	if !regexache.MustCompile(`^[a-z]`).MatchString(value) {

internal/service/rds/validate_test.go

@@ -27,6 +27,11 @@ func TestValidEventSubscriptionName(t *testing.T) {
 	}
 
 	invalidNames := []string{
+		"invalid_name",
+		"invalid-name-",
+		"-invalid-name",
+		"0invalid-name",
+		"invalid--name",
 		"Here is a name with: colon",
 		"and here is another * invalid name",
 		"also $ invalid",
@@ -46,6 +51,46 @@ func TestValidEventSubscriptionName(t *testing.T) {
 	}
 }
 
+func TestValidEventSubscriptionNamePrefix(t *testing.T) {
+	t.Parallel()
+
+	validNames := []string{
+		"valid-name",
+		"valid02-name",
+		"Valid-Name1",
+		"valid-name-",
+	}
+	for _, v := range validNames {
+		_, errors := validEventSubscriptionNamePrefix(v, names.AttrNamePrefix)
+		if len(errors) != 0 {
+			t.Fatalf("%q should be a valid RDS Event Subscription Name: %q", v, errors)
+		}
+	}
+
+	invalidNames := []string{
+		"invalid_name",
+		"-invalid-name",
+		"0invalid-name",
+		"invalid--name",
+		"Here is a name with: colon",
+		"and here is another * invalid name",
+		"also $ invalid",
+		"This . is also %% invalid@!)+(",
+		"*",
+		"",
+		" ",
+		"_",
+		// length > 229
+		strings.Repeat("W", 230),
+	}
+	for _, v := range invalidNames {
+		_, errors := validEventSubscriptionNamePrefix(v, names.AttrNamePrefix)
+		if len(errors) == 0 {
+			t.Fatalf("%q should be an invalid RDS Event Subscription Name Prefix", v)
+		}
+	}
+}
+
 func TestValidOptionGroupName(t *testing.T) {
 	t.Parallel()