CI: Fetching schemas via `cURL` fails

[hpoeche]

In our CI we download the schema files from admin-shell-io/aas-specs to use them in the sdk-test job.

basyx-python-sdk/.github/workflows/ci.yml

Lines 80 to 84 in ca78e9a

	- name: Collect schema files from aas-specs
	run: |
	mkdir -p ./test/adapter/schema
	curl -sSL -o ./test/adapter/schema/aasJSONSchema.json https://raw.githubusercontent.com/admin-shell-io/aas-specs/${{ env.AAS_SPECS_RELEASE_TAG }}/schemas/json/aas.json
	curl -sSL -o ./test/adapter/schema/aasXMLSchema.xsd https://raw.githubusercontent.com/admin-shell-io/aas-specs/${{ env.AAS_SPECS_RELEASE_TAG }}/schemas/xml/AAS.xsd

For the currently set variable value AAS_SPECS_RELEASE_TAG: "IDTA-01001-3-1-2" these URLs do not exist.
Despite the 404 response code of the HTTP Request cURL finishes with status code 0 and the CI step does not fail.

The sdk tests simply skip the tests, that require the schema files:

basyx-python-sdk/sdk/test/adapter/json/test_json_serialization.py

Lines 50 to 54 in ca78e9a

	class JsonSerializationSchemaTest(unittest.TestCase):
	@classmethod
	def setUpClass(cls):
	if not os.path.exists(JSON_SCHEMA_FILE):
	raise unittest.SkipTest(f"JSON Schema does not exist at {JSON_SCHEMA_FILE}, skipping test")

basyx-python-sdk/sdk/test/adapter/xml/test_xml_serialization.py

Lines 50 to 54 in ca78e9a

	class XMLSerializationSchemaTest(unittest.TestCase):
	@classmethod
	def setUpClass(cls):
	if not os.path.exists(XML_SCHEMA_FILE):
	raise unittest.SkipTest(f"XSD schema does not exist at {XML_SCHEMA_FILE}, skipping test")

This explains why this bug stayed unnoticed for so long. To avoid this in future I suggest to

• correct the URL the schemas are downloaded from
• add the -f flag to the curl call to exit non-zero on any errors
• (optionally) rely on a different condition to skip the unittests than existence of the schema files