feat: add custom validation

Author: benediktziegler

commitizen/commands/check.py

@@ -6,7 +6,6 @@
 
 from commitizen import factory, git, out
 from commitizen.exceptions import (
-    CommitMessageLengthExceededError,
     InvalidCommandArgumentError,
     InvalidCommitMessageError,
     NoCommitsFoundError,
@@ -83,26 +82,32 @@ def __call__(self) -> None:
         """Validate if commit messages follows the conventional pattern.
 
         Raises:
-            InvalidCommitMessageError: if the commit provided not follows the conventional pattern
+            InvalidCommitMessageError: if the commit provided does not follow the conventional pattern
             NoCommitsFoundError: if no commit is found with the given range
         """
         commits = self._get_commits()
         if not commits:
             raise NoCommitsFoundError(f"No commit found with range: '{self.rev_range}'")
 
         pattern = re.compile(self.cz.schema_pattern())
-        invalid_msgs_content = "\n".join(
-            f'commit "{commit.rev}": "{commit.message}"'
+        invalid_commits = [
+            (commit, check.errors)
             for commit in commits
-            if not self._validate_commit_message(commit.message, pattern, commit.rev)
-        )
-        if invalid_msgs_content:
-            # TODO: capitalize the first letter of the error message for consistency in v5
+            if not (
+                check := self.cz.validate_commit_message(
+                    commit_msg=commit.message,
+                    pattern=pattern,
+                    allow_abort=self.allow_abort,
+                    allowed_prefixes=self.allowed_prefixes,
+                    max_msg_length=self.max_msg_length,
+                    commit_hash=commit.rev,
+                )
+            ).is_valid
+        ]
+
+        if invalid_commits:
             raise InvalidCommitMessageError(
-                "commit validation: failed!\n"
-                "please enter a commit message in the commitizen format.\n"
-                f"{invalid_msgs_content}\n"
-                f"pattern: {pattern.pattern}"
+                self.cz.format_exception_message(invalid_commits)
             )
         out.success("Commit validation: successful!")
 
@@ -157,24 +162,3 @@ def _filter_comments(msg: str) -> str:
             if not line.startswith("#"):
                 lines.append(line)
         return "\n".join(lines)
-
-    def _validate_commit_message(
-        self, commit_msg: str, pattern: re.Pattern[str], commit_hash: str
-    ) -> bool:
-        if not commit_msg:
-            return self.allow_abort
-
-        if any(map(commit_msg.startswith, self.allowed_prefixes)):
-            return True
-
-        if self.max_msg_length is not None:
-            msg_len = len(commit_msg.partition("\n")[0].strip())
-            if msg_len > self.max_msg_length:
-                raise CommitMessageLengthExceededError(
-                    f"commit validation: failed!\n"
-                    f"commit message length exceeds the limit.\n"
-                    f'commit "{commit_hash}": "{commit_msg}"\n'
-                    f"message length limit: {self.max_msg_length} (actual: {msg_len})"
-                )
-
-        return bool(pattern.match(commit_msg))

commitizen/cz/base.py

@@ -1,12 +1,16 @@
 from __future__ import annotations
 
 from abc import ABCMeta, abstractmethod
-from typing import TYPE_CHECKING, Any, Callable, Protocol
+from collections.abc import Iterable, Mapping
+from typing import TYPE_CHECKING, Any, Callable, NamedTuple, Protocol
 
 from jinja2 import BaseLoader, PackageLoader
 from prompt_toolkit.styles import Style
 
+from commitizen.exceptions import CommitMessageLengthExceededError
+
 if TYPE_CHECKING:
+    import re
     from collections.abc import Iterable, Mapping
 
     from commitizen import git
@@ -26,6 +30,11 @@ def __call__(
     ) -> dict[str, Any]: ...
 
 
+class ValidationResult(NamedTuple):
+    is_valid: bool
+    errors: list
+
+
 class BaseCommitizen(metaclass=ABCMeta):
     bump_pattern: str | None = None
     bump_map: dict[str, str] | None = None
@@ -43,7 +52,7 @@ class BaseCommitizen(metaclass=ABCMeta):
         ("disabled", "fg:#858585 italic"),
     ]
 
-    # The whole subject will be parsed as message by default
+    # The whole subject will be parsed as a message by default
     # This allows supporting changelog for any rule system.
     # It can be modified per rule
     commit_parser: str | None = r"(?P<message>.*)"
@@ -101,3 +110,55 @@ def schema_pattern(self) -> str:
     @abstractmethod
     def info(self) -> str:
         """Information about the standardized commit message."""
+
+    def validate_commit_message(
+        self,
+        *,
+        commit_msg: str,
+        pattern: re.Pattern[str],
+        allow_abort: bool,
+        allowed_prefixes: list[str],
+        max_msg_length: int | None,
+        commit_hash: str,
+    ) -> ValidationResult:
+        """Validate commit message against the pattern."""
+        if not commit_msg:
+            return ValidationResult(
+                allow_abort, [] if allow_abort else ["commit message is empty"]
+            )
+
+        if any(map(commit_msg.startswith, allowed_prefixes)):
+            return ValidationResult(True, [])
+
+        if max_msg_length is not None:
+            msg_len = len(commit_msg.partition("\n")[0].strip())
+            if msg_len > max_msg_length:
+                # TODO: capitalize the first letter of the error message for consistency in v5
+                raise CommitMessageLengthExceededError(
+                    f"commit validation: failed!\n"
+                    f"commit message length exceeds the limit.\n"
+                    f'commit "{commit_hash}": "{commit_msg}"\n'
+                    f"message length limit: {max_msg_length} (actual: {msg_len})"
+                )
+
+        return ValidationResult(
+            bool(pattern.match(commit_msg)),
+            [f"pattern: {pattern.pattern}"],
+        )
+
+    def format_exception_message(
+        self, invalid_commits: list[tuple[git.GitCommit, list]]
+    ) -> str:
+        """Format commit errors."""
+        displayed_msgs_content = "\n".join(
+            [
+                f'commit "{commit.rev}": "{commit.message}\n"' + "\n".join(errors)
+                for commit, errors in invalid_commits
+            ]
+        )
+        # TODO: capitalize the first letter of the error message for consistency in v5
+        return (
+            "commit validation: failed!\n"
+            "please enter a commit message in the commitizen format.\n"
+            f"{displayed_msgs_content}"
+        )