allow parser to deal with null input

jc/parsers/amixer.py

@@ -90,6 +90,7 @@ from typing import Dict
 
 import jc.utils
 from jc.utils import convert_to_int
+from jc.exceptions import ParseError
 
 class info():
     """Provides parser metadata (version, author, etc.)"""
@@ -115,6 +116,9 @@ def _process(proc_data: Dict) -> Dict:
     Returns:
         (dict) processed structured data adhering to the schema
     """
+    if not proc_data:
+        return {}
+
     # Initialize the processed dictionary
     processed = {
         "control_name": proc_data.get("control_name", ""),
@@ -209,6 +213,8 @@ def parse(
 
     # starts the parsing from here
     mapping: Dict = {}
+
+    if jc.utils.has_data(data):
         # split lines and than work on each line
         lines = data.splitlines()
         first_line = lines[0].strip()
@@ -217,7 +223,7 @@ def parse(
         if first_line.startswith("Simple mixer control"):
             control_name = first_line.split("'")[1]
         else:
-        raise ValueError("Invalid amixer output format: missing control name.")
+            raise ParseError("Invalid amixer output format: missing control name.")
         # map the control name
         mapping["control_name"] = control_name
 

tests/test_amixer.py

@@ -22,6 +22,12 @@ class AmixerTests(unittest.TestCase):
         self.test_files_json = [f'{file}.json' for file in self.TEST_FILES_NAME]
         self.test_files_processed_json = [f'{file}-processed.json' for file in self.TEST_FILES_NAME]
 
+    def test_amixer_sget_nodata(self):
+        """
+        Test 'amixer' with no data
+        """
+        self.assertEqual(jc.parsers.amixer.parse('', quiet=True), {})
+
     def test_amixer_sget(self):
         for file_out, file_json, file_processed_json in zip(self.test_files_out, self.test_files_json,
                                                             self.test_files_processed_json):