[Fix rubocop#4197] Fix false positive in Style/RedundantSelf with p…

…arallel assignment

This cop would incorrectly mark a `self` as redundant when used in the
lhs expression of a parallel assignment.

This change fixes that.

CHANGELOG.md

@@ -9,6 +9,7 @@
 * [#4179](https://github.com/bbatsov/rubocop/pull/4179): Prevent `Rails/Blank` from breaking when LHS of `or` is a naked falsiness check. ([@rrosenblum][])
 * [#4172](https://github.com/bbatsov/rubocop/pull/4172): Fix false positives in `Style/MixinGrouping` cop. ([@drenmi][])
 * [#4185](https://github.com/bbatsov/rubocop/pull/4185): Make `Lint/NestedMethodDefinition` aware of `#*_exec` class of methods. ([@drenmi][])
+* [#4197](https://github.com/bbatsov/rubocop/pull/4197): Fix false positive in `Style/RedundantSelf` cop with parallel assignment. ([@drenmi][])
 
 ## 0.48.0 (2017-03-26)
 

lib/rubocop/cop/style/redundant_self.rb

@@ -71,9 +71,7 @@ def on_def(node)
           add_scope(node)
         end
 
-        def on_defs(node)
-          add_scope(node)
-        end
+        alias on_defs on_def
 
         def on_args(node)
           node.children.each { |arg| on_argument(arg) }
@@ -90,6 +88,7 @@ def on_lvasgn(node)
 
         def on_send(node)
           return unless node.self_receiver? && regular_method_call?(node)
+          return if node.parent && node.parent.mlhs_type?
 
           return if @allowed_send_nodes.include?(node) ||
                     @local_variables_scopes[node].include?(node.method_name)

spec/rubocop/cop/style/redundant_self_spec.rb

@@ -21,6 +21,12 @@
     expect(cop.offenses).to be_empty
   end
 
+  it 'accepts a self receiver on an lvalue of a parallel assignment' do
+    src = 'a, self.b = c, d'
+    inspect_source(cop, src)
+    expect(cop.offenses).to be_empty
+  end
+
   it 'accepts a self receiver on an lvalue of an or-assignment' do
     src = 'self.logger ||= Rails.logger'
     inspect_source(cop, src)