Merge pull request #9847 from dvandersluis/issue/9843

[Fix #9843] Fix `Style/RedundantSelf` to allow conditional nodes to use `self` in the condition when a variable named is shadowed inside

changelog/fix_fix_styleredundantself_to_allow.md

@@ -0,0 +1 @@
+* [#9843](https://github.com/rubocop/rubocop/issues/9843): Fix `Style/RedundantSelf` to allow conditional nodes to use `self` in the condition when a variable named is shadowed inside. ([@dvandersluis][])

lib/rubocop/cop/style/redundant_self.rb

@@ -92,7 +92,7 @@ def on_blockarg(node)
 
         def on_masgn(node)
           lhs, rhs = *node
-          lhs.children.each { |child| add_lhs_to_local_variables_scopes(rhs, child.to_a.first) }
+          add_masgn_lhs_variables(rhs, lhs)
         end
 
         def on_lvasgn(node)
@@ -116,6 +116,22 @@ def on_block(node)
           add_scope(node, @local_variables_scopes[node])
         end
 
+        def on_if(node)
+          # Allow conditional nodes to use `self` in the condition if that variable
+          # name is used in an `lvasgn` or `masgn` within the `if`.
+          node.child_nodes.each do |child_node|
+            lhs, _rhs = *child_node
+
+            if child_node.lvasgn_type?
+              add_lhs_to_local_variables_scopes(node.condition, lhs)
+            elsif child_node.masgn_type?
+              add_masgn_lhs_variables(node.condition, lhs)
+            end
+          end
+        end
+        alias on_while on_if
+        alias on_until on_if
+
         private
 
         def add_scope(node, local_variables = [])
@@ -163,6 +179,12 @@ def add_lhs_to_local_variables_scopes(rhs, lhs)
             @local_variables_scopes[rhs] << lhs
           end
         end
+
+        def add_masgn_lhs_variables(rhs, lhs)
+          lhs.children.each do |child|
+            add_lhs_to_local_variables_scopes(rhs, child.to_a.first)
+          end
+        end
       end
     end
   end

spec/rubocop/cop/style/redundant_self_spec.rb

@@ -24,6 +24,56 @@
     expect_no_offenses('a, b = self.a')
   end
 
+  it 'does not report an offense when lvasgn name is used in `if`' do
+    expect_no_offenses('a = self.a if self.a')
+  end
+
+  it 'does not report an offense when masgn name is used in `if`' do
+    expect_no_offenses('a, b = self.a if self.a')
+  end
+
+  it 'does not report an offense when lvasgn name is used in `unless`' do
+    expect_no_offenses('a = self.a unless self.a')
+  end
+
+  it 'does not report an offense when masgn name is used in `unless`' do
+    expect_no_offenses('a, b = self.a unless self.a')
+  end
+
+  it 'does not report an offense when lvasgn name is used in `while`' do
+    expect_no_offenses('a = self.a while self.a')
+  end
+
+  it 'does not report an offense when masgn name is used in `while`' do
+    expect_no_offenses('a, b = self.a while self.a')
+  end
+
+  it 'does not report an offense when lvasgn name is used in `until`' do
+    expect_no_offenses('a = self.a until self.a')
+  end
+
+  it 'does not report an offense when masgn name is used in `until`' do
+    expect_no_offenses('a, b = self.a until self.a')
+  end
+
+  it 'does not report an offense when lvasgn name is nested below `if`' do
+    expect_no_offenses('a = self.a if foo(self.a)')
+  end
+
+  it 'reports an offense when a different lvasgn name is used in `if`' do
+    expect_offense(<<~RUBY)
+      a = x if self.b
+               ^^^^ Redundant `self` detected.
+    RUBY
+  end
+
+  it 'reports an offense when a different masgn name is used in `if`' do
+    expect_offense(<<~RUBY)
+      a, b, c = x if self.d
+                     ^^^^ Redundant `self` detected.
+    RUBY
+  end
+
   it 'does not report an offense when self receiver in a method argument and ' \
      'lvalue have the same name' do
     expect_no_offenses('a = do_something(self.a)')