Change EnforcedStyle to standard_error for Lint/InheritException

This PR change `EnforcedStyle` from `runtime_error` to `standard_error` for `Lint/InheritException`. I noticed this while investigating #10406. Below is the inheritance tree for the exception classes. ``` --------------- | Exception | --------------- ^ | --------------- |StandardError| (default for `rescue`) --------------- ^ | --------------- |RuntimeError | (default for `raise`) --------------- ``` AFAIK, it seems that custom exceptions generally inherit from `StandardError`. Subclasses of `StandardError` are handled with `rescue` by default. `raise` creates a `RuntimeError` when the exception class is omitted. If custom exception inherits from `RuntimeError`, the custom exception and `RuntimeError` will be is-a. If custom exception inherits from `StandardError`, the custom exception and `RuntimeError` will not be is-a. In other words, inheriting `StandardError` will not be mistakenly handled as `raise` which omits the exception class. So, inheriting `StandardError` rather than `RuntimeError` does not include unnecessary inheritance for `rescue` handling.
rubocop · Feb 11, 2022 · bb3a8ab · bb3a8ab
1 parent 4a3d37b
commit bb3a8ab
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diff --git a/changelog/change_enforced_style_for_lint_inherit_exception.md b/changelog/change_enforced_style_for_lint_inherit_exception.md
@@ -0,0 +1 @@
+* [#10407](https://github.com/rubocop/rubocop/pull/10407): Change `EnforcedStyle` from `runtime_error` to `standard_error` for `Lint/InheritException`. ([@koic][])
diff --git a/config/default.yml b/config/default.yml
@@ -1820,10 +1820,10 @@ Lint/InheritException:
   VersionAdded: '0.41'
   VersionChanged: '<<next>>'
   # The default base class in favour of `Exception`.
-  EnforcedStyle: runtime_error
+  EnforcedStyle: standard_error
   SupportedStyles:
-    - runtime_error
     - standard_error
+    - runtime_error
 
 Lint/InterpolationCheck:
   Description: 'Raise warning for interpolation in single q strs.'

diff --git a/lib/rubocop/cop/lint/inherit_exception.rb b/lib/rubocop/cop/lint/inherit_exception.rb
@@ -6,14 +6,14 @@ module Lint
       # This cop looks for error classes inheriting from `Exception`
       # and its standard library subclasses, excluding subclasses of
       # `StandardError`. It is configurable to suggest using either
-      # `RuntimeError` (default) or `StandardError` instead.
+      # `StandardError` (default) or `RuntimeError` instead.
       #
       # @safety
       #   This cop's autocorrection is unsafe because `rescue` that omit
       #   exception class handle `StandardError` and its subclasses,
       #   but not `Exception` and its subclasses.
       #
-      # @example EnforcedStyle: runtime_error (default)
+      # @example EnforcedStyle: standard_error (default)
       #   # bad
       #
       #   class C < Exception; end
@@ -22,11 +22,11 @@ module Lint
       #
       #   # good
       #
-      #   class C < RuntimeError; end
+      #   class C < StandardError; end
       #
-      #   C = Class.new(RuntimeError)
+      #   C = Class.new(StandardError)
       #
-      # @example EnforcedStyle: standard_error
+      # @example EnforcedStyle: runtime_error
       #   # bad
       #
       #   class C < Exception; end
@@ -35,9 +35,9 @@ module Lint
       #
       #   # good
       #
-      #   class C < StandardError; end
+      #   class C < RuntimeError; end
       #
-      #   C = Class.new(StandardError)
+      #   C = Class.new(RuntimeError)
       class InheritException < Base
         include ConfigurableEnforcedStyle
         extend AutoCorrector