Make python fail properly on invalid header

.apigentools-info

@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.5.1.dev2",
-            "regenerated": "2021-12-07 14:20:03.067544",
-            "spec_repo_commit": "df97aef"
+            "regenerated": "2021-12-07 15:59:00.380490",
+            "spec_repo_commit": "c0fb344"
         },
         "v2": {
             "apigentools_version": "1.5.1.dev2",
-            "regenerated": "2021-12-07 14:20:03.592436",
-            "spec_repo_commit": "df97aef"
+            "regenerated": "2021-12-07 15:59:00.863160",
+            "spec_repo_commit": "c0fb344"
         }
     }
 }

.generator/templates/api_client.mustache

@@ -622,6 +622,8 @@ class ApiClient(object):
                     headers['Cookie'] = auth_setting['value']
                 elif auth_setting['in'] == 'header':
                     if auth_setting['type'] != 'http-signature':
+                        if auth_setting["value"] is None:
+                            raise ApiValueError("Invalid authentication token for {}".format(auth_setting["key"]))
                         headers[auth_setting['key']] = auth_setting['value']
 {{#hasHttpSignatureMethods}}
                     else:

tests/test_errors.py

@@ -0,0 +1,15 @@
+import pytest
+
+from datadog_api_client.v1 import Configuration, ApiClient
+from datadog_api_client.v1.api import metrics_api
+from datadog_api_client.v1.exceptions import ApiValueError
+
+
+def test_invalid_header():
+    configuration = Configuration()
+    configuration.api_key["apiKeyAuth"] = None
+
+    with ApiClient(configuration) as api_client:
+        api_instance = metrics_api.MetricsApi(api_client)
+        with pytest.raises(ApiValueError):
+            api_instance.get_metric_metadata("some_metric")