r/aws_cognito_user_pool: Fix runtime error: index out of range [0] with length 0 panic when adding lambda_config

.changelog/38184.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_cognito_user_pool: Fix `runtime error: index out of range [0] with length 0` panic when adding `lambda_config`
+```

internal/service/cognitoidp/user_pool.go

@@ -997,7 +997,14 @@
  if v, ok := d.GetOk("lambda_config"); ok {
  if v, ok := v.([]interface{})[0].(map[string]interface{}); ok && v != nil {
  if d.HasChange("lambda_config.0.pre_token_generation") {
- v["pre_token_generation_config"].([]interface{})[0].(map[string]interface{})["lambda_arn"] = d.Get("lambda_config.0.pre_token_generation")
+ preTokenGeneration := d.Get("lambda_config.0.pre_token_generation")
+ if tfList, ok := v["pre_token_generation_config"].([]interface{}); ok && len(tfList) > 0 && tfList[0] != nil {
+ tfList[0].(map[string]interface{})["lambda_arn"] = preTokenGeneration
+ } else {
+ tfList = []interface{}{map[string]interface{}{
+ "lambda_arn": preTokenGeneration,
+ }}
+ }
  }
 
  if d.HasChange("lambda_config.0.pre_token_generation_config.0.lambda_arn") {

internal/service/cognitoidp/user_pool_test.go

@@ -1334,6 +1334,53 @@ func TestAccCognitoIDPUserPool_WithLambda_preGenerationTokenConfig(t *testing.T)
  })
 }
 
+// https://github.com/hashicorp/terraform-provider-aws/issues/38164.
+func TestAccCognitoIDPUserPool_addLambda(t *testing.T) {
+ ctx := acctest.Context(t)
+ var pool awstypes.UserPoolType
+ rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
+ resourceName := "aws_cognito_user_pool.test"
+ lambdaResourceName := "aws_lambda_function.test"
+
+ resource.ParallelTest(t, resource.TestCase{
+ PreCheck: func() { acctest.PreCheck(ctx, t); testAccPreCheckIdentityProvider(ctx, t) },
+ ErrorCheck: acctest.ErrorCheck(t, names.CognitoIDPServiceID),
+ ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories,
+ CheckDestroy: testAccCheckUserPoolDestroy(ctx),
+ Steps: []resource.TestStep{
+ {
+ Config: testAccUserPoolConfig_name(rName),
+ Check: resource.ComposeAggregateTestCheckFunc(
+ testAccCheckUserPoolExists(ctx, resourceName, &pool),
+ resource.TestCheckResourceAttr(resourceName, "lambda_config.#", acctest.Ct0),
+ ),
+ },
+ {
+ Config: testAccUserPoolConfig_lambda(rName),
+ Check: resource.ComposeAggregateTestCheckFunc(
+ testAccCheckUserPoolExists(ctx, resourceName, &pool),
+ resource.TestCheckResourceAttr(resourceName, "lambda_config.#", acctest.Ct1),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.create_auth_challenge", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.custom_message", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.define_auth_challenge", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.post_authentication", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.post_confirmation", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.pre_authentication", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.pre_sign_up", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.pre_token_generation", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.user_migration", lambdaResourceName, names.AttrARN),
+ resource.TestCheckResourceAttrPair(resourceName, "lambda_config.0.verify_auth_challenge_response", lambdaResourceName, names.AttrARN),
+ ),
+ },
+ {
+ ResourceName: resourceName,
+ ImportState: true,
+ ImportStateVerify: true,
+ },
+ },
+ })
+}
+
 func TestAccCognitoIDPUserPool_schemaAttributes(t *testing.T) {
  ctx := acctest.Context(t)
  var pool1, pool2 awstypes.UserPoolType