Merge pull request #426 from crystal-ameba/fix-issue-409

Do not report expanded arguments in `ShadowingOuterLocalVar` rule

spec/ameba/rule/lint/shadowing_outer_local_var_spec.cr

@@ -31,6 +31,30 @@ module Ameba::Rule::Lint
         CRYSTAL
     end
 
+    pending "reports if there is a shadowing in an unpacked variable in a block" do
+      expect_issue subject, <<-CRYSTAL
+        def some_method
+          foo = 1
+
+          [{3}].each do |(foo)|
+                        # ^ error: Shadowing outer local variable `foo`
+          end
+        end
+        CRYSTAL
+    end
+
+    pending "reports if there is a shadowing in an unpacked variable in a block (2)" do
+      expect_issue subject, <<-CRYSTAL
+        def some_method
+          foo = 1
+
+          [{[3]}].each do |((foo))|
+                           # ^ error: Shadowing outer local variable `foo`
+          end
+        end
+        CRYSTAL
+    end
+
     it "does not report outer vars declared below shadowed block" do
       expect_no_issues subject, <<-CRYSTAL
         methods = klass.methods.select { |m| m.annotation(MyAnn) }

src/ameba/rule/lint/shadowing_outer_local_var.cr

@@ -53,13 +53,16 @@ module Ameba::Rule::Lint
       return unless outer_scope = scope.outer_scope
 
       scope.arguments.reject(&.ignored?).each do |arg|
-        variable = outer_scope.find_variable(arg.name)
+        # TODO: handle unpacked variables from `Block#unpacks`
+        next unless name = arg.name.presence
+
+        variable = outer_scope.find_variable(name)
 
         next if variable.nil? || !variable.declared_before?(arg)
-        next if outer_scope.assigns_ivar?(arg.name)
-        next if outer_scope.assigns_type_dec?(arg.name)
+        next if outer_scope.assigns_ivar?(name)
+        next if outer_scope.assigns_type_dec?(name)
 
-        issue_for arg.node, MSG % arg.name
+        issue_for arg.node, MSG % name
       end
     end
   end