fix: Test stdout output

Author: tmathern

src/c2pa/c2pa.py

@@ -1380,20 +1380,22 @@ def wrapped_callback(
             # signature length for correctness.
             try:
                 if not data_ptr or data_len <= 0:
-                    # Error: invalid input, native code will handle if seeing
-                    # signature size being 0
+                    # Error: invalid input, invalid so return -1,
+                    # native code will handle it!
                     return -1
 
                 # Convert C pointer to Python bytes
                 data = bytes(data_ptr[:data_len])
                 if not data:
-                    # Error: empty data, native code will handle it!
+                    # Error: empty data, invalid so return -1,
+                    # native code will also handle it!
                     return -1
 
                 # Call the user's callback
                 signature = callback(data)
                 if not signature:
-                    # Error: empty signature, native code will handle that too!
+                    # Error: empty signature, invalid so return -1,
+                    # native code will handle that too!
                     return -1
 
                 # Copy the signature back to the C buffer (since callback is
@@ -1408,6 +1410,8 @@ def wrapped_callback(
                 print(
                     error_messages['callback_error'].format(
                         str(e)), file=sys.stderr)
+                # Error: exception raised, invalid so return -1,
+                # native code will handle the error when seeing -1
                 return -1
 
         # Encode strings with error handling in case it's invalid UTF8

tests/test_unit_tests.py

@@ -244,6 +244,9 @@ def test_read_cawg_data_file(self):
 
 class TestBuilder(unittest.TestCase):
     def setUp(self):
+        # Filter deprecation warnings for create_signer function
+        warnings.filterwarnings("ignore", message="The create_signer function is deprecated")
+        
         # Use the fixtures_dir fixture to set up paths
         self.data_dir = FIXTURES_DIR
         self.testPath = DEFAULT_TEST_FILE
@@ -1223,6 +1226,7 @@ def setUp(self):
         # Filter specific deprecation warnings for legacy API tests
         warnings.filterwarnings("ignore", message="The read_file function is deprecated")
         warnings.filterwarnings("ignore", message="The sign_file function is deprecated")
+        warnings.filterwarnings("ignore", message="The read_ingredient_file function is deprecated")
 
         self.data_dir = FIXTURES_DIR
         self.testPath = DEFAULT_TEST_FILE