Improve exception reporting for CLI commands

changelog/6856.improvement.md

@@ -0,0 +1,16 @@
+Improved exception handling within Rasa Open Source.
+
+All exceptions that are somewhat expected (e.g. errors in file formats like 
+configurations or training data) will share a common base class 
+`RasaException`.
+
+::warning Backwards Incompatibility
+Base class for the exception raised when an action can not be found has been changed
+from a `NameError` to a `ValueError`.
+::
+
+Some other exceptions have also slightly changed:
+- raise `YamlSyntaxException` instead of YAMLError (from ruamel) when 
+  failing to load a yaml file with information about the line where loading failed
+- introduced `MissingDependencyException` as an exception raised if packages 
+  need to be installed

rasa/__main__.py

@@ -1,29 +1,33 @@
-import sys
 import argparse
 import logging
+import os
 import platform
+import sys
+
+from rasa_sdk import __version__ as rasa_sdk_version
 
-import rasa.utils.io
 from rasa import version
-import rasa.telemetry
 from rasa.cli import (
-    scaffold,
-    run,
-    train,
+    data,
+    export,
     interactive,
+    run,
+    scaffold,
     shell,
     telemetry,
     test,
+    train,
     visualize,
-    data,
     x,
-    export,
 )
 from rasa.cli.arguments.default_arguments import add_logging_options
 from rasa.cli.utils import parse_last_positional_argument_as_model_path
-from rasa.utils.common import set_log_level, set_log_and_warnings_filters
+from rasa.shared.exceptions import RasaException
+from rasa.shared.utils.cli import print_error
+import rasa.telemetry
+from rasa.utils.common import set_log_and_warnings_filters, set_log_level
+import rasa.utils.io
 import rasa.utils.tensorflow.environment as tf_env
-from rasa_sdk import __version__ as rasa_sdk_version
 
 logger = logging.getLogger(__name__)
 
@@ -89,8 +93,6 @@ def print_version() -> None:
 
 def main() -> None:
     # Running as standalone python application
-    import os
-    import sys
 
     parse_last_positional_argument_as_model_path()
     arg_parser = create_argument_parser()
@@ -106,17 +108,25 @@ def main() -> None:
     # insert current path in syspath so custom modules are found
     sys.path.insert(1, os.getcwd())
 
-    if hasattr(cmdline_arguments, "func"):
-        rasa.utils.io.configure_colored_logging(log_level)
-        set_log_and_warnings_filters()
-        rasa.telemetry.initialize_error_reporting()
-        cmdline_arguments.func(cmdline_arguments)
-    elif hasattr(cmdline_arguments, "version"):
-        print_version()
-    else:
-        # user has not provided a subcommand, let's print the help
-        logger.error("No command specified.")
-        arg_parser.print_help()
+    try:
+        if hasattr(cmdline_arguments, "func"):
+            rasa.utils.io.configure_colored_logging(log_level)
+            set_log_and_warnings_filters()
+            rasa.telemetry.initialize_error_reporting()
+            cmdline_arguments.func(cmdline_arguments)
+        elif hasattr(cmdline_arguments, "version"):
+            print_version()
+        else:
+            # user has not provided a subcommand, let's print the help
+            logger.error("No command specified.")
+            arg_parser.print_help()
+            sys.exit(1)
+    except RasaException as e:
+        # these are exceptions we expect to happen (e.g. invalid training data format)
+        # it doesn't make sense to print a stacktrace for these if we are not in
+        # debug mode
+        logger.debug("Failed to run CLI command due to an exception.", exc_info=e)
+        print_error(f"{e.__class__.__name__}: {e}")
         sys.exit(1)
 
 

rasa/cli/test.py

@@ -127,12 +127,10 @@ def run_nlu_test(args: argparse.Namespace) -> None:
         for file in args.config:
             try:
                 validation_utils.validate_yaml_schema(
-                    rasa.shared.utils.io.read_file(file),
-                    CONFIG_SCHEMA_FILE,
-                    show_validation_errors=False,
+                    rasa.shared.utils.io.read_file(file), CONFIG_SCHEMA_FILE,
                 )
                 config_files.append(file)
-            except validation_utils.InvalidYamlFileError:
+            except validation_utils.YamlValidationException:
                 logger.debug(
                     f"Ignoring file '{file}' as it is not a valid config file."
                 )

rasa/core/actions/action.py

@@ -35,6 +35,7 @@
     ACTION_BACK_NAME,
     REQUESTED_SLOT,
 )
+from rasa.shared.exceptions import RasaException
 from rasa.shared.nlu.constants import INTENT_NAME_KEY, INTENT_RANKING_KEY
 from rasa.shared.core.events import (
     UserUtteranceReverted,
@@ -661,7 +662,7 @@ def name(self) -> Text:
         return self._name
 
 
-class ActionExecutionRejection(Exception):
+class ActionExecutionRejection(RasaException):
     """Raising this exception will allow other policies
     to predict a different action"""
 

rasa/core/featurizers/tracker_featurizers.py

@@ -3,6 +3,7 @@
 import jsonpickle
 import logging
 
+from rasa.shared.exceptions import RasaException
 from rasa.shared.nlu.constants import TEXT
 from tqdm import tqdm
 from typing import Tuple, List, Optional, Dict, Text, Union
@@ -22,18 +23,15 @@
 logger = logging.getLogger(__name__)
 
 
-class InvalidStory(Exception):
+class InvalidStory(RasaException):
     """Exception that can be raised if story cannot be featurized."""
 
     def __init__(self, message) -> None:
         self.message = message
         super(InvalidStory, self).__init__()
 
     def __str__(self) -> Text:
-        # return message in error colours
-        return rasa.shared.utils.io.wrap_with_color(
-            self.message, color=rasa.shared.utils.io.bcolors.FAIL
-        )
+        return self.message
 
 
 class TrackerFeaturizer:

rasa/core/policies/ensemble.py

@@ -9,6 +9,7 @@
 from typing import Text, Optional, Any, List, Dict, Tuple, Set, NamedTuple, Union
 
 import rasa.core
+from rasa.shared.exceptions import RasaException
 import rasa.shared.utils.common
 import rasa.shared.utils.io
 import rasa.utils.io
@@ -380,7 +381,6 @@ def from_dict(cls, policy_configuration: Dict[Text, Any]) -> List[Policy]:
         parsed_policies = []
 
         for policy in policies:
-            policy_name = policy.pop("name")
             if policy.get("featurizer"):
                 featurizer_func, featurizer_config = cls.get_featurizer_from_dict(
                     policy
@@ -401,6 +401,7 @@ def from_dict(cls, policy_configuration: Dict[Text, Any]) -> List[Policy]:
                 # override policy's featurizer with real featurizer class
                 policy["featurizer"] = featurizer_func(**featurizer_config)
 
+            policy_name = policy.pop("name")
             try:
                 constr_func = registry.policy_from_module_path(policy_name)
                 try:
@@ -424,7 +425,11 @@ def from_dict(cls, policy_configuration: Dict[Text, Any]) -> List[Policy]:
     def get_featurizer_from_dict(cls, policy) -> Tuple[Any, Any]:
         # policy can have only 1 featurizer
         if len(policy["featurizer"]) > 1:
-            raise InvalidPolicyConfig("policy can have only 1 featurizer")
+            raise InvalidPolicyConfig(
+                f"Every policy can only have 1 featurizer "
+                f"but '{policy.get('name')}' "
+                f"uses {len(policy['featurizer'])} featurizers."
+            )
         featurizer_config = policy["featurizer"][0]
         featurizer_name = featurizer_config.pop("name")
         featurizer_func = registry.featurizer_from_module_path(featurizer_name)
@@ -435,7 +440,11 @@ def get_featurizer_from_dict(cls, policy) -> Tuple[Any, Any]:
     def get_state_featurizer_from_dict(cls, featurizer_config) -> Tuple[Any, Any]:
         # featurizer can have only 1 state featurizer
         if len(featurizer_config["state_featurizer"]) > 1:
-            raise InvalidPolicyConfig("featurizer can have only 1 state featurizer")
+            raise InvalidPolicyConfig(
+                f"Every featurizer can only have 1 state "
+                f"featurizer but one of the featurizers uses "
+                f"{len(featurizer_config['state_featurizer'])}."
+            )
         state_featurizer_config = featurizer_config["state_featurizer"][0]
         state_featurizer_name = state_featurizer_config.pop("name")
         state_featurizer_func = registry.state_featurizer_from_module_path(
@@ -737,7 +746,7 @@ def _check_policy_for_forms_available(
         )
 
 
-class InvalidPolicyConfig(Exception):
+class InvalidPolicyConfig(RasaException):
     """Exception that can be raised when policy config is not valid."""
 
     pass

rasa/core/policies/rule_policy.py

@@ -6,6 +6,7 @@
 import json
 
 from rasa.shared.constants import DOCS_URL_RULES
+from rasa.shared.exceptions import RasaException
 import rasa.shared.utils.io
 from rasa.shared.core.events import FormValidation, UserUttered, ActionExecuted
 from rasa.core.featurizers.tracker_featurizers import TrackerFeaturizer
@@ -56,20 +57,17 @@
 DO_NOT_PREDICT_LOOP_ACTION = "do_not_predict_loop_action"
 
 
-class InvalidRule(Exception):
+class InvalidRule(RasaException):
     """Exception that can be raised when rules are not valid."""
 
     def __init__(self, message: Text) -> None:
         super().__init__()
-        self.message = message + (
-            f"\nYou can find more information about the usage of "
-            f"rules at {DOCS_URL_RULES}. "
-        )
+        self.message = message
 
     def __str__(self) -> Text:
-        # return message in error colours
-        return rasa.shared.utils.io.wrap_with_color(
-            self.message, color=rasa.shared.utils.io.bcolors.FAIL
+        return self.message + (
+            f"\nYou can find more information about the usage of "
+            f"rules at {DOCS_URL_RULES}. "
         )
 
 
@@ -370,7 +368,7 @@ def _find_contradicting_rules(
         if error_messages:
             error_messages = "\n".join(error_messages)
             raise InvalidRule(
-                f"\nContradicting rules or stories found🚨\n\n{error_messages}\n"
+                f"\nContradicting rules or stories found 🚨\n\n{error_messages}\n"
                 f"Please update your stories and rules so that they don't contradict "
                 f"each other."
             )

rasa/core/run.py

@@ -290,11 +290,3 @@ async def load_agent_on_start(
 
     logger.info("Rasa server is up and running.")
     return app.agent
-
-
-if __name__ == "__main__":
-    raise RuntimeError(
-        "Calling `rasa.core.run` directly is no longer supported. "
-        "Please use `rasa run` to start a Rasa server or `rasa shell` to chat with "
-        "your bot on the command line."
-    )

rasa/core/test.py

@@ -868,11 +868,3 @@ async def _evaluate_core_model(model: Text, stories_file: Text) -> int:
     )
     failed_stories = story_eval_store.failed_stories
     return number_of_stories - len(failed_stories)
-
-
-if __name__ == "__main__":
-    raise RuntimeError(
-        "Calling `rasa.core.test` directly is no longer supported. Please use "
-        "`rasa test` to test a combined Core and NLU model or `rasa test core` "
-        "to test a Core model."
-    )

rasa/core/train.py

@@ -179,11 +179,3 @@ def do_interactive_learning(
         conversation_id=args.conversation_id,
         server_args=args.__dict__,
     )
-
-
-if __name__ == "__main__":
-    raise RuntimeError(
-        "Calling `rasa.core.train` directly is no longer supported. Please use "
-        "`rasa train` to train a combined Core and NLU model or `rasa train core` "
-        "to train a Core model."
-    )

rasa/core/visualize.py

@@ -63,11 +63,3 @@ async def visualize(
     import webbrowser
 
     webbrowser.open(full_output_path)
-
-
-if __name__ == "__main__":
-    raise RuntimeError(
-        "Calling `rasa.core.visualize` directly is "
-        "no longer supported. "
-        "Please use `rasa visualize` instead."
-    )