Merge pull request #450 from crystal-ameba/fix-issue-447

Exclude reporting type declarations passed as call arguments

spec/ameba/rule/lint/useless_assign_spec.cr

@@ -388,19 +388,29 @@ module Ameba::Rule::Lint
           CRYSTAL
       end
 
-      it "doesn't report if this is a record declaration" do
+      it "doesn't report record declaration" do
         expect_no_issues subject, <<-CRYSTAL
+          record Foo, foo : String
           record Foo, foo = "foo"
           CRYSTAL
       end
 
-      it "doesn't report if this is a record declaration (generics)" do
+      it "doesn't report record declarations (generics)" do
         expect_no_issues subject, <<-CRYSTAL
           record Foo(T), foo : T
+          record Foo(T), foo = T.new
           CRYSTAL
       end
 
-      it "doesn't report if this is an accessor declaration" do
+      it "doesn't report type declaration as a call argument" do
+        expect_no_issues subject, <<-CRYSTAL
+          foo Foo(T), foo : T
+          foo Foo, foo : Nil
+          foo foo : String, bar : Int32?
+          CRYSTAL
+      end
+
+      it "doesn't report accessor declarations" do
         accessor_macros = %w[setter class_setter]
         %w[getter class_getter property class_property].each do |name|
           accessor_macros << name

src/ameba/rule/lint/useless_assign.cr

@@ -43,8 +43,13 @@ module Ameba::Rule::Lint
 
       scope.variables.each do |var|
         next if var.ignored? || var.used_in_macro? || var.captured_by_block?
-        next if exclude_type_declarations? && scope.assigns_type_dec?(var.name)
-
+        if scope.assigns_type_dec?(var.name)
+          next if exclude_type_declarations?
+          # exclude type declarations within calls
+          if node.is_a?(Crystal::Expressions)
+            next if node.expressions.first?.is_a?(Crystal::Call)
+          end
+        end
         var.assignments.each do |assign|
           next if assign.referenced?
           issue_for assign.target_node, MSG % var.name