refactor(bump_rule): make bump_rule a property

Author: bearomorphism

commitizen/commands/bump.py

@@ -8,7 +8,6 @@
 
 from commitizen import bump, factory, git, hooks, out
 from commitizen.bump_rule import (
-    CustomBumpRule,
     SemVerIncrement,
 )
 from commitizen.changelog_formats import get_changelog_format
@@ -24,7 +23,6 @@
     InvalidManualVersion,
     NoCommitsFoundError,
     NoneIncrementExit,
-    NoPatternMapError,
     NotAGitProjectError,
     NotAllowed,
     NoVersionSpecifiedError,
@@ -124,34 +122,11 @@ def is_initial_tag(
 
     def find_increment(self, commits: list[git.GitCommit]) -> SemVerIncrement | None:
         # Update the bump map to ensure major version doesn't increment.
-        is_major_version_zero: bool = self.bump_settings["major_version_zero"]
-
-        # Fallback to custom bump rule if no bump rule is provided
-        rule = self.cz.bump_rule or CustomBumpRule(
-            *self._get_validated_cz_bump(),
-        )
+        is_major_version_zero = bool(self.bump_settings["major_version_zero"])
 
         return SemVerIncrement.get_highest_by_messages(
             (commit.message for commit in commits),
-            lambda x: rule.get_increment(x, is_major_version_zero),
-        )
-
-    def _get_validated_cz_bump(
-        self,
-    ) -> tuple[str, dict[str, SemVerIncrement], dict[str, SemVerIncrement]]:
-        """For fixing the type errors"""
-        bump_pattern = self.cz.bump_pattern
-        bump_map = self.cz.bump_map
-        bump_map_major_version_zero = self.cz.bump_map_major_version_zero
-        if not bump_pattern or not bump_map or not bump_map_major_version_zero:
-            raise NoPatternMapError(
-                f"'{self.config.settings['name']}' rule does not support bump"
-            )
-
-        return (
-            bump_pattern,
-            SemVerIncrement.safe_cast_dict(bump_map),
-            SemVerIncrement.safe_cast_dict(bump_map_major_version_zero),
+            lambda x: self.cz.bump_rule.get_increment(x, is_major_version_zero),
         )
 
     def __call__(self) -> None:  # noqa: C901

commitizen/cz/base.py

@@ -2,15 +2,17 @@
 
 from abc import ABCMeta, abstractmethod
 from collections.abc import Iterable
+from functools import cached_property
 from typing import Any, Callable, Protocol
 
 from jinja2 import BaseLoader, PackageLoader
 from prompt_toolkit.styles import Style, merge_styles
 
 from commitizen import git
-from commitizen.bump_rule import BumpRule
+from commitizen.bump_rule import BumpRule, CustomBumpRule, SemVerIncrement
 from commitizen.config.base_config import BaseConfig
 from commitizen.defaults import Questions
+from commitizen.exceptions import NoPatternMapError
 
 
 class MessageBuilderHook(Protocol):
@@ -26,9 +28,9 @@ def __call__(
 
 
 class BaseCommitizen(metaclass=ABCMeta):
-    bump_rule: BumpRule | None = None
+    _bump_rule: BumpRule | None = None
 
-    # TODO: deprecate these
+    # TODO: decide if these should be removed
     bump_pattern: str | None = None
     bump_map: dict[str, str] | None = None
     bump_map_major_version_zero: dict[str, str] | None = None
@@ -89,6 +91,25 @@ def style(self):
             ]
         )
 
+    @cached_property
+    def bump_rule(self) -> BumpRule:
+        if self._bump_rule:
+            return self._bump_rule
+
+        # Fallback to custom bump rule if no bump rule is provided
+        bump_pattern = self.bump_pattern
+        bump_map = self.bump_map
+        bump_map_major_version_zero = self.bump_map_major_version_zero
+        if not bump_pattern or not bump_map or not bump_map_major_version_zero:
+            raise NoPatternMapError(
+                f"Rule does not support bump: {bump_pattern=}, {bump_map=}, {bump_map_major_version_zero=}"
+            )
+        return CustomBumpRule(
+            bump_pattern,
+            SemVerIncrement.safe_cast_dict(bump_map),
+            SemVerIncrement.safe_cast_dict(bump_map_major_version_zero),
+        )
+
     def example(self) -> str:
         """Example of the commit message."""
         raise NotImplementedError("Not Implemented yet")

commitizen/cz/conventional_commits/conventional_commits.py

@@ -29,7 +29,7 @@ def parse_subject(text):
 
 
 class ConventionalCommitsCz(BaseCommitizen):
-    bump_rule = ConventionalCommitBumpRule()
+    _bump_rule = ConventionalCommitBumpRule()
 
     bump_pattern = defaults.BUMP_PATTERN
     bump_map = defaults.BUMP_MAP