fix: raise ConfigFileNotFound when explicit runtime config path is missing (#560)

invoke/__init__.py

@@ -8,6 +8,7 @@
     AmbiguousEnvVar,
     AuthFailure,
     CollectionNotFound,
+    ConfigFileNotFound,
     CommandTimedOut,
     Exit,
     ParseError,

invoke/config.py

@@ -9,7 +9,11 @@
 from typing import Any, Dict, Iterator, Optional, Tuple, Type, Union
 
 from .env import Environment
-from .exceptions import UnknownFileType, UnpicklableConfigMember
+from .exceptions import (
+    ConfigFileNotFound,
+    UnknownFileType,
+    UnpicklableConfigMember,
+)
 from .runners import Local
 from .terminals import WINDOWS
 from .util import debug, yaml
@@ -899,6 +903,11 @@ def _load_file(
             # Typically means 'no such file', so just note & skip past.
             except IOError as e:
                 if e.errno == 2:
+                    # Absolute paths (runtime config) were explicitly given by
+                    # the user; a missing file is an error,
+                    # not "not configured".
+                    if absolute:
+                        raise ConfigFileNotFound(str(filepath)) from e
                     err = "Didn't see any {}, skipping."
                     debug(err.format(filepath))
                 else:

invoke/exceptions.py

@@ -286,6 +286,28 @@ class UnknownFileType(Exception):
     pass
 
 
+class ConfigFileNotFound(IOError):
+    """
+    A runtime config file was explicitly specified but could not be found.
+
+    Raised by `Config._load_file` when the user supplies an explicit path
+    (via ``--config`` on the CLI or ``runtime_path=`` kwarg) and that file
+    does not exist. Unlike the implicit search for system/user/project config
+    files — where a missing file simply means "not configured" — a missing
+    *explicit* runtime config is always a user error.
+
+    .. versionadded:: 2.3
+    """
+
+    def __init__(self, path: str) -> None:
+        self.path = path
+        msg = (
+            "Runtime config file {!r} was not found."
+            " Check the path for typos."
+        )
+        super().__init__(msg.format(path))
+
+
 class UnpicklableConfigMember(Exception):
     """
     A config file contained module objects, which can't be pickled/copied.

tests/_support/configs/dedupe.yaml

@@ -0,0 +1,2 @@
+tasks:
+  dedupe: true

tests/config.py

@@ -12,6 +12,7 @@
 from invoke.exceptions import (
     AmbiguousEnvVar,
     UncastableEnvVar,
+    ConfigFileNotFound,
     UnknownFileType,
     UnpicklableConfigMember,
 )
@@ -619,6 +620,24 @@ def unknown_suffix_in_runtime_path_raises_useful_error(self):
             c = Config(runtime_path=join(CONFIGS_PATH, "screw.ini"))
             c.load_runtime()
 
+        @raises(ConfigFileNotFound)
+        def missing_runtime_path_raises_config_file_not_found(self):
+            # Regression for #560: when the user provides an explicit runtime
+            # config path that doesn't exist, invoke should raise immediately
+            # instead of silently continuing with no config loaded.
+            c = Config(
+                runtime_path=join(CONFIGS_PATH, "nonexistent_typo.yaml")
+            )
+            c.load_runtime()
+
+        def missing_runtime_path_error_includes_path(self):
+            # ConfigFileNotFound.path must match what was supplied.
+            bad = join(CONFIGS_PATH, "nonexistent_typo.yaml")
+            c = Config(runtime_path=bad)
+            with pytest.raises(ConfigFileNotFound) as exc_info:
+                c.load_runtime()
+            assert exc_info.value.path == bad
+
         def python_modules_dont_load_special_vars(self):
             "Python modules don't load special vars"
             # Borrow another test's Python module.
@@ -639,13 +658,14 @@ def python_modules_except_usefully_on_unpicklable_modules(self):
             with pytest.raises(UnpicklableConfigMember, match=expected):
                 c.load_runtime(merge=False)
 
-        @patch("invoke.config.debug")
-        def nonexistent_files_are_skipped_and_logged(self, mock_debug):
+        @raises(ConfigFileNotFound)
+        def missing_explicit_runtime_path_raises(self):
+            # Regression for #560: explicit runtime paths that don't exist must
+            # raise ConfigFileNotFound, not silently continue.
             c = Config()
             c._load_yml = Mock(side_effect=IOError(2, "aw nuts"))
             c.set_runtime_path("is-a.yml")  # Triggers use of _load_yml
             c.load_runtime()
-            mock_debug.assert_any_call("Didn't see any is-a.yml, skipping.")
 
         @raises(IOError)
         def non_missing_file_IOErrors_are_raised(self):