fix: config env cannot be anything other than default (#1769)

samcli/cli/cli_config_file.py

@@ -103,11 +103,12 @@ def configuration_callback(cmd_name, option_name, config_env_name, saved_callbac
     ctx.default_map = ctx.default_map or {}
     cmd_name = cmd_name or ctx.info_name
     param.default = None
-    config_env_name = value or config_env_name
+    # explicitly ignore values passed to --config-env, can be opened up in the future.
+    config_env_name = DEFAULT_ENV
     config = get_ctx_defaults(cmd_name, provider, ctx, config_env_name=config_env_name)
     ctx.default_map.update(config)
 
-    return saved_callback(ctx, param, value) if saved_callback else value
+    return saved_callback(ctx, param, config_env_name) if saved_callback else config_env_name
 
 
 def get_ctx_defaults(cmd_name, provider, ctx, config_env_name):

tests/unit/cli/test_cli_config_file.py

@@ -6,7 +6,7 @@
 
 from samcli.commands.exceptions import ConfigException
 from samcli.cli.cli_config_file import TomlProvider, configuration_option, configuration_callback, get_ctx_defaults
-from samcli.lib.config.samconfig import SamConfig
+from samcli.lib.config.samconfig import SamConfig, DEFAULT_ENV
 
 
 class MockContext:
@@ -58,6 +58,7 @@ class TestCliConfiguration(TestCase):
     def setUp(self):
         self.cmd_name = "test_cmd"
         self.option_name = "test_option"
+        # No matter what config-env is passed in, default is chosen.
         self.config_env = "test_config_env"
         self.saved_callback = MagicMock()
         self.provider = MagicMock()
@@ -85,8 +86,9 @@ def test_callback_with_valid_config_env(self):
             value=self.value,
         )
         self.assertEqual(self.saved_callback.call_count, 1)
-        for arg in [self.ctx, self.param, self.value]:
+        for arg in [self.ctx, self.param, DEFAULT_ENV]:
             self.assertIn(arg, self.saved_callback.call_args[0])
+        self.assertNotIn(self.value, self.saved_callback.call_args[0])
 
     def test_configuration_option(self):
         toml_provider = TomlProvider()