fix: Raise correct exception when Domain BasePath contains non-str items (#2756)

Author: aahung

samtranslator/model/api/api_generator.py

@@ -17,7 +17,12 @@
     ApiGatewayApiKey,
 )
 from samtranslator.model.route53 import Route53RecordSetGroup
-from samtranslator.model.exceptions import InvalidDocumentException, InvalidResourceException, InvalidTemplateException
+from samtranslator.model.exceptions import (
+    ExpectedType,
+    InvalidDocumentException,
+    InvalidResourceException,
+    InvalidTemplateException,
+)
 from samtranslator.model.s3_utils.uri_parser import parse_s3_uri
 from samtranslator.region_configuration import RegionConfiguration
 from samtranslator.schema.common import PassThrough
@@ -524,6 +529,7 @@ def _construct_api_domain(
             basepath_mapping.Stage = ref(rest_api.logical_id + ".Stage")
             basepath_resource_list.extend([basepath_mapping])
         else:
+            sam_expect(basepaths, self.logical_id, "Domain.BasePath").to_be_a_list_of(ExpectedType.STRING)
             for basepath in basepaths:
                 # Remove possible leading and trailing '/' because a base path may only
                 # contain letters, numbers, and one of "$-_.+!*'()"

tests/translator/input/error_api_with_custom_domains_invalid.yaml

@@ -77,3 +77,14 @@ Resources:
       OpenApiVersion: 3.0.1
       StageName: Prod
       Domain: !Ref MyDomainName  # this should be a map after solution
+
+  MyApiWithIncorrectBasePathItemType:
+    Type: AWS::Serverless::Api
+    Properties:
+      OpenApiVersion: 3.0.1
+      StageName: Prod
+      Domain:
+        DomainName: api-example.com
+        CertificateArn: my-api-cert-arn
+        BasePath:
+        - 3 # this should not be a number

tests/translator/output/error_api_with_custom_domains_invalid.json

@@ -1,3 +1,3 @@
 {
-  "errorMessage": "Invalid Serverless Application Specification document. Number of errors found: 4. Resource with id [MyApi] is invalid. EndpointConfiguration for Custom Domains must be one of ['EDGE', 'REGIONAL', 'PRIVATE']. Resource with id [MyApiInvalidDomainType] is invalid. Property 'Domain' should be a map. Resource with id [MyApiMissingCertificateArn] is invalid. Property 'Domain.CertificateArn' is required. Resource with id [ServerlessRestApi] is invalid. Property 'Domain.DomainName' is required."
+  "errorMessage": "Invalid Serverless Application Specification document. Number of errors found: 5. Resource with id [MyApi] is invalid. EndpointConfiguration for Custom Domains must be one of ['EDGE', 'REGIONAL', 'PRIVATE']. Resource with id [MyApiInvalidDomainType] is invalid. Property 'Domain' should be a map. Resource with id [MyApiMissingCertificateArn] is invalid. Property 'Domain.CertificateArn' is required. Resource with id [MyApiWithIncorrectBasePathItemType] is invalid. Property 'Domain.BasePath[0]' should be a string. Resource with id [ServerlessRestApi] is invalid. Property 'Domain.DomainName' is required."
 }