[fix#cli]: Improve exception handling and error output

A global exception handler has been added that intercepts critical errors (for example, `FileNotFoundError` or other unexpected failures) and outputs a clear message to the user instead of a full stack of calls.

- For debugging, the full traceback is now sent to logs, if the logging level allows it.
- For this, support for the `exc_info` parameter has been added to `Console.print`.
- The "Validation failed" message now has a WARNING level.

Author: Qu1nel

src/code_validator/cli.py

@@ -105,18 +105,24 @@ def run_from_cli() -> None:
             console.print("Validation successful.", level=LogLevel.INFO, is_verdict=True)
             sys.exit(ExitCode.SUCCESS)
         else:
-            console.print("Validation failed.", level=LogLevel.INFO, is_verdict=True)
+            console.print("Validation failed.", level=LogLevel.WARNING, is_verdict=True)
             sys.exit(ExitCode.VALIDATION_FAILED)
 
     except CodeValidatorError as e:
-        console.print("Error: Internal Error of validator!", level=LogLevel.CRITICAL)
-        logger.exception(f"Traceback for CodeValidatorError: {e}")
+        console.print(
+            f"Error: An internal validator error occurred: {e}", level=LogLevel.CRITICAL, show_user=True, exc_info=True
+        )
         sys.exit(ExitCode.VALIDATION_FAILED)
     except FileNotFoundError as e:
-        console.print(f"Error: File not found - {e.filename}!", level=LogLevel.CRITICAL)
-        logger.exception(f"Traceback for FileNotFoundError: {e}")
+        console.print(
+            f"Error: Input file not found: {e.filename}", level=LogLevel.CRITICAL, show_user=True, exc_info=True
+        )
         sys.exit(ExitCode.FILE_NOT_FOUND)
     except Exception as e:
-        console.print(f"An unexpected error occurred: {e.__class__.__name__}!", level=LogLevel.CRITICAL)
-        logger.exception(f"Traceback for unexpected error: {e}")
+        console.print(
+            f"Error: An unexpected error occurred: {e.__class__.__name__}. See logs for detailed traceback.",
+            level=LogLevel.CRITICAL,
+            show_user=True,
+            exc_info=True,
+        )
         sys.exit(ExitCode.UNEXPECTED_ERROR)

src/code_validator/core.py

@@ -166,6 +166,49 @@ def _parse_ast_tree(self) -> bool:
             self._console.print(f"Syntax Error found: {e}", level=LogLevel.ERROR)
             return False
 
+    def _report_errors(self) -> None:
+        """Formats and prints collected validation errors to the console.
+
+        This method is responsible for presenting the final list of failed
+        rules to the user. It respects the `--max-messages` configuration
+        to avoid cluttering the terminal. If the number of found errors
+        exceeds the specified limit, it truncates the output and displays
+        a summary message indicating how many more errors were found.
+
+        The method retrieves the list of failed rules from `self._failed_rules`
+        and the display limit from `self._config`. All user-facing output is
+        channeled through the `self._console` object.
+
+        It performs the following steps:
+          1. Checks if any errors were recorded. If not, it returns immediately.
+          2. Determines the subset of errors to display based on the configured
+             `max_messages` limit (a value of 0 means no limit).
+          3. Iterates through the selected error rules and prints their
+             failure messages.
+          4. If the error list was truncated, prints a summary line, e.g.,
+             "... (5 more errors found)".
+        """
+        max_errors = self._config.max_messages
+        num_errors = len(self._failed_rules)
+
+        if num_errors == 0:
+            return None
+
+        errors_to_show = self._failed_rules
+        if 0 < max_errors < num_errors:
+            errors_to_show = self._failed_rules[:max_errors]
+
+        for rule in errors_to_show:
+            self._console.print(rule.config.message, level=LogLevel.WARNING, show_user=True)
+
+        if 0 < max_errors < num_errors:
+            remaining_count = num_errors - max_errors
+            self._console.print(
+                f"... ({remaining_count} more error{'s' if remaining_count > 1 else ''} found)",
+                level=LogLevel.WARNING,
+                show_user=True,
+            )
+
     def run(self) -> bool:
         """Runs the entire validation process from start to finish.
 
@@ -184,6 +227,7 @@ def run(self) -> bool:
             self._load_and_parse_rules()
 
             if not self._parse_ast_tree():
+                self._report_errors()
                 return False
 
             self._console.print("Lead source code, load and parse rules and parsing code - PASS", level=LogLevel.DEBUG)
@@ -223,4 +267,6 @@ def run(self) -> bool:
             else:
                 self._console.print(f"Rule {rule.config.rule_id} - PASS", level=LogLevel.INFO)
 
+        self._report_errors()
+
         return not self._failed_rules

src/code_validator/output.py

@@ -210,6 +210,7 @@ def print(
         level: LogLevel | Literal["TRACE", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] = LogLevel.TRACE,
         is_verdict: bool = False,
         show_user: bool = False,
+        exc_info: bool = False,
     ) -> None:
         """Prints a message to stdout and logs it simultaneously.
 
@@ -228,9 +229,10 @@ def print(
             show_user:  If True and `is_verdict=False`, allows
                         printing non-verdict messages to stdout. Defaults to
                         False.
+            exc_info:   If True this work as loggings.exception("<message>").
         """
         level_num = logging.getLevelName(level if isinstance(level, LogLevel) else level)
-        self._logger.log(level_num, message, stacklevel=2)
+        self._logger.log(level_num, message, stacklevel=2, exc_info=exc_info)
 
         if (not self._is_quiet) and ((not is_verdict and show_user) or (is_verdict and self._show_verdict)):
             print(message, file=self._stdout)