Merge pull request #7913 from koic/false_positive_for_lint_literal_as…

…_condition

Fix a false positive for `Lint/LiteralAsCondition`

CHANGELOG.md

@@ -22,6 +22,7 @@
 * [#7899](https://github.com/rubocop-hq/rubocop/issues/7899): Fix an infinite loop error for `Layout/SpaceAroundOperators` with `Layout/ExtraSpacing` when using `ForceEqualSignAlignment: true`. ([@koic][])
 * [#7885](https://github.com/rubocop-hq/rubocop/issues/7885): Fix `Style/IfUnlessModifier` logic when tabs are used for indentation. ([@jonas054][])
 * [#7909](https://github.com/rubocop-hq/rubocop/pull/7909): Fix a false positive for `Lint/ParenthesesAsGroupedExpression` when using an intended grouped parentheses. ([@koic][])
+* [#7913](https://github.com/rubocop-hq/rubocop/pull/7913): Fix a false positive for `Lint/LiteralAsCondition` when using `true` literal in `while` and similar cases. ([@koic][])
 
 ### Changes
 

lib/rubocop/cop/lint/literal_as_condition.rb

@@ -10,26 +10,25 @@ module Lint
       # @example
       #
       #   # bad
-      #
       #   if 20
       #     do_something
       #   end
       #
-      # @example
-      #
       #   # bad
-      #
       #   if some_var && true
       #     do_something
       #   end
       #
-      # @example
-      #
       #   # good
-      #
       #   if some_var && some_condition
       #     do_something
       #   end
+      #
+      #   # good
+      #   # When using a boolean value for an infinite loop.
+      #   while true
+      #     break if condition
+      #   end
       class LiteralAsCondition < Cop
         MSG = 'Literal `%<literal>s` appeared as a condition.'
 
@@ -38,20 +37,18 @@ def on_if(node)
         end
 
         def on_while(node)
-          check_for_literal(node)
-        end
+          return if condition(node).true_type?
 
-        def on_while_post(node)
           check_for_literal(node)
         end
+        alias on_while_post on_while
 
         def on_until(node)
-          check_for_literal(node)
-        end
+          return if condition(node).false_type?
 
-        def on_until_post(node)
           check_for_literal(node)
         end
+        alias on_until_post on_until
 
         def on_case(case_node)
           if case_node.condition

manual/cops_lint.md

@@ -993,24 +993,25 @@ if/while/until.
 
 ```ruby
 # bad
-
 if 20
   do_something
 end
-```
-```ruby
-# bad
 
+# bad
 if some_var && true
   do_something
 end
-```
-```ruby
-# good
 
+# good
 if some_var && some_condition
   do_something
 end
+
+# good
+# When using a boolean value for an infinite loop.
+while true
+  break if condition
+end
 ```
 
 ## Lint/LiteralInInterpolation

spec/rubocop/cop/lint/literal_as_condition_spec.rb

@@ -176,4 +176,36 @@
       end
     RUBY
   end
+
+  it 'accepts `true` literal in `while`' do
+    expect_no_offenses(<<~RUBY)
+      while true
+        break if condition
+      end
+    RUBY
+  end
+
+  it 'accepts `true` literal in post-loop `while`' do
+    expect_no_offenses(<<~RUBY)
+      begin
+        break if condition
+      end while true
+    RUBY
+  end
+
+  it 'accepts `false` literal in `until`' do
+    expect_no_offenses(<<~RUBY)
+      until false
+        break if condition
+      end
+    RUBY
+  end
+
+  it 'accepts `false` literal in post-loop `until`' do
+    expect_no_offenses(<<~RUBY)
+      begin
+        break if condition
+      end until false
+    RUBY
+  end
 end