APIGW: fix selection pattern for AWS Lambda integration (#12580)

bentsku · web-flow · commit 7a2f96f5ea32 · 2025-05-06T10:25:16.000+02:00
diff --git a/localstack-core/localstack/services/apigateway/next_gen/execute_api/handlers/integration_response.py b/localstack-core/localstack/services/apigateway/next_gen/execute_api/handlers/integration_response.py
@@ -69,7 +69,7 @@ def __call__(
         # we first need to find the right IntegrationResponse based on their selection template, linked to the status
         # code of the Response
         if integration_type == IntegrationType.AWS and "lambda:path/" in integration["uri"]:
-            selection_value = self.parse_error_message_from_lambda(body) or str(status_code)
+            selection_value = self.parse_error_message_from_lambda(body)
         else:
             selection_value = str(status_code)
 
diff --git a/tests/aws/services/apigateway/test_apigateway_lambda.py b/tests/aws/services/apigateway/test_apigateway_lambda.py
@@ -832,22 +832,35 @@ def test_lambda_selection_patterns(
         resourceId=resource_id,
         httpMethod="GET",
         statusCode="200",
+        selectionPattern="",
     )
     # 4xx
     aws_client.apigateway.put_integration_response(
         restApiId=api_id,
         resourceId=resource_id,
         httpMethod="GET",
         statusCode="405",
-        selectionPattern=".*400.*",
+        selectionPattern=".*four hundred.*",
     )
+
     # 5xx
     aws_client.apigateway.put_integration_response(
         restApiId=api_id,
         resourceId=resource_id,
         httpMethod="GET",
         statusCode="502",
-        selectionPattern=".*5\\d\\d.*",
+        selectionPattern=".+",
+    )
+
+    # assert that this does not get matched even though it's the status code returned by the Lambda, showing that
+    # AWS does match on the status code for this specific integration
+    # https://docs.aws.amazon.com/apigateway/latest/api/API_IntegrationResponse.html
+    aws_client.apigateway.put_integration_response(
+        restApiId=api_id,
+        resourceId=resource_id,
+        httpMethod="GET",
+        statusCode="504",
+        selectionPattern="200",
     )
 
     aws_client.apigateway.create_deployment(restApiId=api_id, stageName="dev")
diff --git a/tests/aws/services/apigateway/test_apigateway_lambda.snapshot.json b/tests/aws/services/apigateway/test_apigateway_lambda.snapshot.json
@@ -1473,23 +1473,23 @@
     }
   },
   "tests/aws/services/apigateway/test_apigateway_lambda.py::test_lambda_selection_patterns": {
-    "recorded-date": "05-09-2023, 21:54:21",
+    "recorded-date": "05-05-2025, 14:10:11",
     "recorded-content": {
       "lambda-selection-pattern-200": "Pass",
       "lambda-selection-pattern-400": {
-        "errorMessage": "Error: Raising 400 from within the Lambda function",
+        "errorMessage": "Error: Raising four hundred from within the Lambda function",
         "errorType": "Exception",
         "requestId": "<uuid:1>",
         "stackTrace": [
-          "  File \"/var/task/lambda_select_pattern.py\", line 7, in handler\n    raise Exception(\"Error: Raising 400 from within the Lambda function\")\n"
+          "  File \"/var/task/lambda_select_pattern.py\", line 7, in handler\n    raise Exception(\"Error: Raising four hundred from within the Lambda function\")\n"
         ]
       },
       "lambda-selection-pattern-500": {
-        "errorMessage": "Error: Raising 500 from within the Lambda function",
+        "errorMessage": "Error: Raising five hundred from within the Lambda function",
         "errorType": "Exception",
         "requestId": "<uuid:2>",
         "stackTrace": [
-          "  File \"/var/task/lambda_select_pattern.py\", line 9, in handler\n    raise Exception(\"Error: Raising 500 from within the Lambda function\")\n"
+          "  File \"/var/task/lambda_select_pattern.py\", line 9, in handler\n    raise Exception(\"Error: Raising five hundred from within the Lambda function\")\n"
         ]
       }
     }
diff --git a/tests/aws/services/apigateway/test_apigateway_lambda.validation.json b/tests/aws/services/apigateway/test_apigateway_lambda.validation.json
@@ -30,7 +30,7 @@
     "last_validated_date": "2024-05-31T19:17:51+00:00"
   },
   "tests/aws/services/apigateway/test_apigateway_lambda.py::test_lambda_selection_patterns": {
-    "last_validated_date": "2023-09-05T19:54:21+00:00"
+    "last_validated_date": "2025-05-05T14:10:11+00:00"
   },
   "tests/aws/services/apigateway/test_apigateway_lambda.py::test_put_integration_aws_proxy_uri": {
     "last_validated_date": "2025-03-03T12:58:39+00:00"
diff --git a/tests/aws/services/lambda_/functions/lambda_select_pattern.py b/tests/aws/services/lambda_/functions/lambda_select_pattern.py
@@ -4,8 +4,8 @@ def handler(event, context):
         case "200":
             return "Pass"
         case "400":
-            raise Exception("Error: Raising 400 from within the Lambda function")
+            raise Exception("Error: Raising four hundred from within the Lambda function")
         case "500":
-            raise Exception("Error: Raising 500 from within the Lambda function")
+            raise Exception("Error: Raising five hundred from within the Lambda function")
         case _:
             return "Error Value in the json request should either be 400 or 500 to demonstrate"

Original file line number	Diff line number	Diff line change
`@@ -1473,23 +1473,23 @@`
`1473`	`1473`	`}`
`1474`	`1474`	`},`
`1475`	`1475`	`"tests/aws/services/apigateway/test_apigateway_lambda.py::test_lambda_selection_patterns": {`
`1476`		`- "recorded-date": "05-09-2023, 21:54:21",`
	`1476`	`+ "recorded-date": "05-05-2025, 14:10:11",`
`1477`	`1477`	`"recorded-content": {`
`1478`	`1478`	`"lambda-selection-pattern-200": "Pass",`
`1479`	`1479`	`"lambda-selection-pattern-400": {`
`1480`		`- "errorMessage": "Error: Raising 400 from within the Lambda function",`
	`1480`	`+ "errorMessage": "Error: Raising four hundred from within the Lambda function",`
`1481`	`1481`	`"errorType": "Exception",`
`1482`	`1482`	`"requestId": "<uuid:1>",`
`1483`	`1483`	`"stackTrace": [`
`1484`		`- " File \"/var/task/lambda_select_pattern.py\", line 7, in handler\n raise Exception(\"Error: Raising 400 from within the Lambda function\")\n"`
	`1484`	`+ " File \"/var/task/lambda_select_pattern.py\", line 7, in handler\n raise Exception(\"Error: Raising four hundred from within the Lambda function\")\n"`
`1485`	`1485`	`]`
`1486`	`1486`	`},`
`1487`	`1487`	`"lambda-selection-pattern-500": {`
`1488`		`- "errorMessage": "Error: Raising 500 from within the Lambda function",`
	`1488`	`+ "errorMessage": "Error: Raising five hundred from within the Lambda function",`
`1489`	`1489`	`"errorType": "Exception",`
`1490`	`1490`	`"requestId": "<uuid:2>",`
`1491`	`1491`	`"stackTrace": [`
`1492`		`- " File \"/var/task/lambda_select_pattern.py\", line 9, in handler\n raise Exception(\"Error: Raising 500 from within the Lambda function\")\n"`
	`1492`	`+ " File \"/var/task/lambda_select_pattern.py\", line 9, in handler\n raise Exception(\"Error: Raising five hundred from within the Lambda function\")\n"`
`1493`	`1493`	`]`
`1494`	`1494`	`}`
`1495`	`1495`	`}`