From 7dfe09ccae5b1a8309326e5a5cb3172fbcd795d3 Mon Sep 17 00:00:00 2001
From: Gautham Goli <goligautham@gmail.com>
Date: Mon, 14 Aug 2017 01:09:06 +0530
Subject: [PATCH] Add tests for fileUtils call in system

---
 Library/Homebrew/rubocops/lines_cop.rb        | 15 ++++++-------
 .../Homebrew/test/rubocops/lines_cop_spec.rb  | 21 +++++++++++++++++++
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/Library/Homebrew/rubocops/lines_cop.rb b/Library/Homebrew/rubocops/lines_cop.rb
index 7a0e08ba29..1b7a1935e3 100644
--- a/Library/Homebrew/rubocops/lines_cop.rb
+++ b/Library/Homebrew/rubocops/lines_cop.rb
@@ -263,13 +263,14 @@ module RuboCop
             problem "Dir([\"#{string_content(path)}\"]) is unnecessary; just use \"#{match[0]}\""
           end
 
-          #
-          # fileUtils_methods= FileUtils.singleton_methods(false).map { |m| Regexp.escape(m) }.join "|"
-          # find_method_with_args(body_node, :system, /fileUtils_methods/) do |m|
-          #   method = string_content(@offensive_node)
-          #   problem "Use the `#{method}` Ruby method instead of `#{m.source}`"
-          # end
-          #
+
+          fileUtils_methods= Regexp.new(FileUtils.singleton_methods(false).map { |m| Regexp.escape(m) }.join "|")
+          find_every_method_call_by_name(body_node, :system).each do |m|
+            param = parameters(m).first
+            next unless match = regex_match_group(param, fileUtils_methods)
+            problem "Use the `#{match}` Ruby method instead of `#{m.source}`"
+          end
+
           # if find_method_def(@processed_source.ast)
           #   problem "Define method #{method_name(@offensive_node)} in the class body, not at the top-level"
           # end
diff --git a/Library/Homebrew/test/rubocops/lines_cop_spec.rb b/Library/Homebrew/test/rubocops/lines_cop_spec.rb
index 203f8a7d97..1af5d2e727 100644
--- a/Library/Homebrew/test/rubocops/lines_cop_spec.rb
+++ b/Library/Homebrew/test/rubocops/lines_cop_spec.rb
@@ -571,6 +571,27 @@ describe RuboCop::Cop::FormulaAudit::Miscellaneous do
 
       inspect_source(cop, source)
 
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+    it "with system call to fileUtils Method" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          desc "foo"
+          url 'http://example.com/foo-1.0.tgz'
+          system "mkdir", "foo"
+        end
+      EOS
+
+      expected_offenses = [{  message: "Use the `mkdir` Ruby method instead of `system \"mkdir\", \"foo\"`",
+                              severity: :convention,
+                              line: 4,
+                              column: 10,
+                              source: source }]
+
+      inspect_source(cop, source)
+
       expected_offenses.zip(cop.offenses).each do |expected, actual|
         expect_offense(expected, actual)
       end