[Fix #7299] Implement Lint/RaiseException cop

CHANGELOG.md

@@ -189,6 +189,7 @@
 * [#7317](https://github.com/rubocop-hq/rubocop/pull/7317): Add new formatter `pacman`. ([@crojasaragonez][])
 * [#6075](https://github.com/rubocop-hq/rubocop/issues/6075): Support `IgnoredPatterns` option for `Naming/MethodName` cop. ([@koic][])
 * [#7335](https://github.com/rubocop-hq/rubocop/pull/7335): Add todo as an alias to disable. `--disable-uncorrectable` will now disable cops using `rubocop:todo` instead of `rubocop:disable`. ([@desheikh][])
+* [#7299](https://github.com/rubocop-hq/rubocop/issues/7299): Add new `Lint/RaiseException` cop. ([@denys281][])
 
 ### Bug fixes
 
@@ -4387,6 +4388,7 @@
 [@jdkaplan]: https://github.com/jdkaplan
 [@cstyles]: https://github.com/cstyles
 [@avmnu-sng]: https://github.com/avmnu-sng
+[@denys281]: https://github.com/denys281
 [@tyler-ball]: https://github.com/tyler-ball
 [@ayacai115]: https://github.com/ayacai115
 [@ozydingo]: https://github.com/ozydingo
@@ -4404,4 +4406,4 @@
 [@jemmaissroff]: https://github.com/jemmaissroff
 [@nikitasakov]: https://github.com/nikitasakov
 [@dmolesUC]: https://github.com/dmolesUC
-[@yuritomanek]: https://github.com/yuritomanek
+[@yuritomanek]: https://github.com/yuritomanek

config/default.yml

@@ -1566,6 +1566,12 @@ Lint/PercentSymbolArray:
   Enabled: true
   VersionAdded: '0.41'
 
+Lint/RaiseException:
+  Description: Checks for `raise` or `fail` statements which are raising `Exception` class.
+  StyleGuide: '#raise-exception'
+  Enabled: true
+  VersionAdded: '0.75'
+
 Lint/RandOne:
   Description: >-
                  Checks for `rand(1)` calls. Such calls always return `0`

lib/rubocop.rb

@@ -326,6 +326,7 @@
 require_relative 'rubocop/cop/lint/parentheses_as_grouped_expression'
 require_relative 'rubocop/cop/lint/percent_string_array'
 require_relative 'rubocop/cop/lint/percent_symbol_array'
+require_relative 'rubocop/cop/lint/raise_exception'
 require_relative 'rubocop/cop/lint/rand_one'
 require_relative 'rubocop/cop/lint/redundant_cop_disable_directive'
 require_relative 'rubocop/cop/lint/redundant_cop_enable_directive'

lib/rubocop/cop/lint/raise_exception.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Lint
+      # This cop checks for `raise` or `fail` statements which are
+      # raising `Exception` class.
+      #
+      # @example
+      #   # bad
+      #   raise Exception, 'Error message here'
+      #
+      #   # good
+      #   raise StandardError, 'Error message here'
+      class RaiseException < Cop
+        MSG = 'Use `StandardError` over `Exception`.'
+
+        def_node_matcher :exception?, <<~PATTERN
+          (send nil? ${:raise :fail} (const _ :Exception) ... )
+        PATTERN
+
+        def_node_matcher :exception_new_with_message?, <<~PATTERN
+          (send nil? ${:raise :fail}
+            (send (const _ :Exception) :new ... ))
+        PATTERN
+
+        def on_send(node)
+          add_offense(node) if raise_exception?(node)
+        end
+
+        private
+
+        def raise_exception?(node)
+          exception?(node) || exception_new_with_message?(node)
+        end
+      end
+    end
+  end
+end

manual/cops.md

@@ -221,6 +221,7 @@ In the following section you find all available cops:
 * [Lint/ParenthesesAsGroupedExpression](cops_lint.md#lintparenthesesasgroupedexpression)
 * [Lint/PercentStringArray](cops_lint.md#lintpercentstringarray)
 * [Lint/PercentSymbolArray](cops_lint.md#lintpercentsymbolarray)
+* [Lint/RaiseException](cops_lint.md#lintraiseexception)
 * [Lint/RandOne](cops_lint.md#lintrandone)
 * [Lint/RedundantCopDisableDirective](cops_lint.md#lintredundantcopdisabledirective)
 * [Lint/RedundantCopEnableDirective](cops_lint.md#lintredundantcopenabledirective)

manual/cops_lint.md

@@ -1516,6 +1516,29 @@ rather than meant to be part of the resulting symbols.
 %i(foo bar)
 ```
 
+## Lint/RaiseException
+
+Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
+--- | --- | --- | --- | ---
+Enabled | Yes | No | 0.75 | -
+
+This cop checks for `raise` or `fail` statements which are
+raising `Exception` class.
+
+### Examples
+
+```ruby
+# bad
+raise Exception, 'Error message here'
+
+# good
+raise StandardError, 'Error message here'
+```
+
+### References
+
+* [https://rubystyle.guide#raise-exception](https://rubystyle.guide#raise-exception)
+
 ## Lint/RandOne
 
 Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged

spec/rubocop/cop/lint/raise_exception_spec.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Lint::RaiseException do
+  subject(:cop) { described_class.new }
+
+  it 'registers an offense for `raise` with `::Exception`' do
+    expect_offense(<<~RUBY)
+      raise ::Exception
+      ^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `::Exception.new`' do
+    expect_offense(<<~RUBY)
+      raise ::Exception.new 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `::Exception` and message' do
+    expect_offense(<<~RUBY)
+      raise ::Exception, 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `Exception`' do
+    expect_offense(<<~RUBY)
+      raise Exception
+      ^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `Exception` and message' do
+    expect_offense(<<~RUBY)
+      raise Exception, 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `Exception.new` and message' do
+    expect_offense(<<~RUBY)
+      raise Exception.new 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `raise` with `Exception.new(args*)` ' do
+    expect_offense(<<~RUBY)
+      raise Exception.new('arg1', 'arg2')
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `fail` with `Exception`' do
+    expect_offense(<<~RUBY)
+      fail Exception
+      ^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `fail` with `Exception` and message' do
+    expect_offense(<<~RUBY)
+      fail Exception, 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'registers an offense for `fail` with `Exception.new` and message' do
+    expect_offense(<<~RUBY)
+      fail Exception.new 'Error with exception'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `StandardError` over `Exception`.
+    RUBY
+  end
+
+  it 'does not register an offense for `raise` without arguments' do
+    expect_no_offenses('raise')
+  end
+
+  it 'does not register an offense for `fail` without arguments' do
+    expect_no_offenses('fail')
+  end
+end