[Fix #10185] Fix a false positive for Lint/AmbiguousRange

changelog/fix_false_positive_for_lint_ambiguous_range.md

@@ -0,0 +1 @@
+* [#10185](https://github.com/rubocop/rubocop/issues/10185): Fix a false positive for `Lint/AmbiguousRange` when using `self` in a range literal. ([@koic][])

lib/rubocop/cop/lint/ambiguous_range.rb

@@ -82,7 +82,7 @@ def each_boundary(range)
         def acceptable?(node)
           node.begin_type? ||
             node.basic_literal? ||
-            node.variable? || node.const_type? ||
+            node.variable? || node.const_type? || node.self_type? ||
             (node.call_type? && acceptable_call?(node))
         end
 

spec/rubocop/cop/lint/ambiguous_range_spec.rb

@@ -74,6 +74,13 @@
         RUBY
       end
 
+      it 'does not register an offense for `self`' do
+        expect_no_offenses(<<~RUBY)
+          self#{operator}42
+          42#{operator}self
+        RUBY
+      end
+
       it 'can handle an endless range', :ruby26 do
         expect_offense(<<~RUBY)
           x || 1#{operator}