[BUGFIX] Do not load YAML unless dict is returned (#541)

src/ytdl_sub/utils/yaml.py

@@ -36,13 +36,18 @@ def load_yaml(file_path: str | Path) -> Dict:
 
     try:
         with open(file_path, "r", encoding="utf-8") as file:
-            return yaml.safe_load(file)
+            output = yaml.safe_load(file)
     except YAMLError as yaml_exception:
         logger.debug(yaml_exception)
         raise InvalidYamlException(
             f"'{file_path}' has invalid YAML, copy-paste it into a YAML checker to find the issue."
         ) from yaml_exception
 
+    if not isinstance(output, dict):
+        raise InvalidYamlException(f"'{file_path}' was specified but does not contain any YAML.")
+
+    return output
+
 
 def dump_yaml(to_dump: Dict) -> str:
     """

tests/unit/utils/test_yaml.py

@@ -35,17 +35,59 @@ def bad_yaml_file_path(bad_yaml) -> str:
         FileHandler.delete(tmp_file.name)
 
 
+@pytest.fixture
+def single_int_file_path(bad_yaml) -> str:
+    # Do not delete the file in the context manager - for Windows compatibility
+    with tempfile.NamedTemporaryFile(suffix=".yaml", delete=False) as tmp_file:
+        tmp_file.write("0".encode("utf-8"))
+        tmp_file.flush()
+
+    try:
+        yield tmp_file.name
+    finally:
+        FileHandler.delete(tmp_file.name)
+
+
+@pytest.fixture
+def empty_yaml_file_path(bad_yaml) -> str:
+    # Do not delete the file in the context manager - for Windows compatibility
+    with tempfile.NamedTemporaryFile(suffix=".yaml", delete=False) as tmp_file:
+        pass
+
+    try:
+        yield tmp_file.name
+    finally:
+        FileHandler.delete(tmp_file.name)
+
+
 def test_load_yaml_file_not_found():
     file_path = "does_not_exist.yaml"
     with pytest.raises(FileNotFoundException, match=f"The file '{file_path}' does not exist."):
         load_yaml(file_path=file_path)
 
 
-def test_load_yaml_invalid_syntax(bad_yaml_file_path):
+def test_load_yaml_invalid_syntax(bad_yaml_file_path: str):
     with pytest.raises(
         InvalidYamlException,
         match=re.escape(
-            f"'{bad_yaml_file_path}' has invalid YAML, copy-paste it into a YAML checker to find the issue."
+            f"'{bad_yaml_file_path}' has invalid YAML, "
+            f"copy-paste it into a YAML checker to find the issue."
         ),
     ):
         load_yaml(file_path=bad_yaml_file_path)
+
+
+def test_empty_yaml(empty_yaml_file_path: str):
+    with pytest.raises(
+        InvalidYamlException,
+        match=re.escape(f"'{empty_yaml_file_path}' was specified but does not contain any YAML."),
+    ):
+        load_yaml(file_path=empty_yaml_file_path)
+
+
+def test_empty_yaml_only_int(single_int_file_path: str):
+    with pytest.raises(
+        InvalidYamlException,
+        match=re.escape(f"'{single_int_file_path}' was specified but does not contain any YAML."),
+    ):
+        load_yaml(file_path=single_int_file_path)