ci: Adds a test case in the CI (#16)

* feat: Adds additional safeguards

* ci: Adds test case

* fix: Fixed typo

Author: frgfm

.github/license-notice.txt

@@ -0,0 +1,2 @@
+# This program is licensed under the Apache License 2.0.
+# See LICENSE or go to <https://www.apache.org/licenses/LICENSE-2.0> for full license details.

.github/workflows/tests.yml

@@ -22,4 +22,6 @@ jobs:
       - name: Build docker
         run: docker build . -t header-validator:py3.8.13-alpine
       - name: Run action
-        run: docker run --workdir /github/workspace -v "/home/runner/work/validate-python-headers/validate-python-headers":"/github/workspace" header-validator:py3.8.13-alpine 'François-Guillaume Fernandez' 2022 Apache-2.0 src/ __init__.py .github/ ''
+        run: |
+          docker run --workdir /github/workspace -v "/home/runner/work/validate-python-headers/validate-python-headers":"/github/workspace" header-validator:py3.8.13-alpine 'François-Guillaume Fernandez' 2022 Apache-2.0 src/ __init__.py .github/ ''
+          docker run --workdir /github/workspace -v "/home/runner/work/validate-python-headers/validate-python-headers":"/github/workspace" header-validator:py3.8.13-alpine 'François-Guillaume Fernandez' 2022 '' src/ __init__.py .github/ .github/license-notice.txt

src/validate_headers.py

@@ -34,7 +34,7 @@ def get_header_options(
 
     # License check
     license_notices = []
-    if isinstance(license_id, str):
+    if isinstance(license_id, str) and len(license_id) > 0:
         license_info = LICENSES.get(license_id)
         if not isinstance(license_info, dict):
             raise KeyError(f"Invalid license identifier: {license_id}")
@@ -48,7 +48,7 @@ def get_header_options(
             ]
             for url in license_info["urls"]
         ]
-    elif isinstance(license_notice, str):
+    elif isinstance(license_notice, str) and len(license_notice) > 0:
         if not Path(license_notice).is_file():
             raise FileNotFoundError("Unable to locate the text of the license notice.")
         with open(license_notice, "r") as f: