add support to so-yaml for using yaml file content for values

salt/manager/tools/sbin/so-yaml_test.py

@@ -361,6 +361,29 @@ class TestRemove(unittest.TestCase):
         self.assertEqual(soyaml.convertType("FALSE"), False)
         self.assertEqual(soyaml.convertType(""), "")
 
+    def test_convert_file(self):
+        import tempfile
+        import os
+
+        # Create a temporary YAML file
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.yaml', delete=False) as f:
+            f.write("test:\n  - name: hi\n    color: blue\n")
+            temp_file = f.name
+
+        try:
+            result = soyaml.convertType(f"file:{temp_file}")
+            expected = {"test": [{"name": "hi", "color": "blue"}]}
+            self.assertEqual(result, expected)
+        finally:
+            os.unlink(temp_file)
+
+    def test_convert_file_nonexistent(self):
+        with patch('sys.exit', new=MagicMock()) as sysmock:
+            with patch('sys.stderr', new=StringIO()) as mock_stderr:
+                soyaml.convertType("file:/nonexistent/file.yaml")
+                sysmock.assert_called_once_with(1)
+                self.assertIn("File '/nonexistent/file.yaml' does not exist.", mock_stderr.getvalue())
+
     def test_get_int(self):
         with patch('sys.stdout', new=StringIO()) as mock_stdout:
             filename = "/tmp/so-yaml_test-get.yaml"