Add tests for autocorrect

Library/Homebrew/rubocops/lines.rb

@@ -267,7 +267,7 @@ module RuboCop
           shell_metacharacters = %w[> < < | ; : & * $ ? : ~ + @ !` ( ) [ ]]
 
           find_every_method_call_by_name(body_node, :system).each do |method|
-            # Continue if a shell metacharacter is present
+            # Only separate when no shell metacharacters are present
             next if shell_metacharacters.any? { |meta| string_content(parameters(method).first).include?(meta) }
 
             next unless match = regex_match_group(parameters(method).first, shell_cmd_with_spaces_regex)
@@ -281,7 +281,7 @@ module RuboCop
             find_instance_method_call(body_node, "Utils", command) do |method|
               index = parameters(method).first.hash_type? ? 1 : 0
 
-              # Continue if a shell metacharacter is present
+              # Only separate when no shell metacharacters are present
               next if shell_metacharacters.any? { |meta| string_content(parameters(method)[index]).include?(meta) }
 
               next unless match = regex_match_group(parameters(method)[index], shell_cmd_with_spaces_regex)

Library/Homebrew/test/rubocops/lines_spec.rb

@@ -715,6 +715,111 @@ describe RuboCop::Cop::FormulaAudit::ShellCommands do
         end
       RUBY
     end
+
+    it "separates shell commands in system" do
+      source = <<~RUBY
+        class Foo < Formula
+          def install
+            system "foo bar"
+          end
+        end
+      RUBY
+
+      corrected_source = <<~RUBY
+        class Foo < Formula
+          def install
+            system "foo", "bar"
+          end
+        end
+      RUBY
+
+      new_source = autocorrect_source(source)
+      expect(new_source).to eq(corrected_source)
+    end
+
+    it "separates shell commands with string interpolation in system" do
+      source = <<~RUBY
+        class Foo < Formula
+          def install
+            system "\#{foo}/bar baz"
+          end
+        end
+      RUBY
+
+      corrected_source = <<~RUBY
+        class Foo < Formula
+          def install
+            system "\#{foo}/bar", "baz"
+          end
+        end
+      RUBY
+
+      new_source = autocorrect_source(source)
+      expect(new_source).to eq(corrected_source)
+    end
+
+    it "separates shell commands in Utils.popen_read" do
+      source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read("foo bar")
+          end
+        end
+      RUBY
+
+      corrected_source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read("foo", "bar")
+          end
+        end
+      RUBY
+
+      new_source = autocorrect_source(source)
+      expect(new_source).to eq(corrected_source)
+    end
+
+    it "separates shell commands with string interpolation in Utils.popen_read" do
+      source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read("\#{foo}/bar baz")
+          end
+        end
+      RUBY
+
+      corrected_source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read("\#{foo}/bar", "baz")
+          end
+        end
+      RUBY
+
+      new_source = autocorrect_source(source)
+      expect(new_source).to eq(corrected_source)
+    end
+
+    it "separates shell commands following a shell variable in Utils.popen_read" do
+      source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read({ "SHELL" => "bash" }, "foo bar")
+          end
+        end
+      RUBY
+
+      corrected_source = <<~RUBY
+        class Foo < Formula
+          def install
+            Utils.popen_read({ "SHELL" => "bash" }, "foo", "bar")
+          end
+        end
+      RUBY
+
+      new_source = autocorrect_source(source)
+      expect(new_source).to eq(corrected_source)
+    end
   end
 end