command postcss flag argument is a separate array member

following the convention used for assembling the overall command

Author: flavorjones

lib/tailwindcss/commands.rb

@@ -74,15 +74,19 @@ def executable(exe_path: DEFAULT_DIR)
       end
 
       def compile_command(debug: false, **kwargs)
-        [
+        command = [
           executable(**kwargs),
           "-i", Rails.root.join("app/assets/stylesheets/application.tailwind.css").to_s,
           "-o", Rails.root.join("app/assets/builds/tailwind.css").to_s,
           "-c", Rails.root.join("config/tailwind.config.js").to_s,
-        ].tap do |command|
-          command << "--minify" unless (debug || rails_css_compressor?)
-          command << "--postcss #{Rails.root.join("config/postcss.config.js")}" if File.exist?(Rails.root.join("config/postcss.config.js"))
-        end
+        ]
+
+        command << "--minify" unless (debug || rails_css_compressor?)
+
+        postcss_path = Rails.root.join("config/postcss.config.js")
+        command += ["--postcss", postcss_path.to_s] if File.exist?(postcss_path)
+
+        command
       end
 
       def watch_command(always: false, poll: false, **kwargs)

test/lib/tailwindcss/commands_test.rb

@@ -158,15 +158,17 @@ def mock_local_tailwindcss_install
           actual = Tailwindcss::Commands.compile_command(exe_path: dir)
           assert_kind_of(Array, actual)
           assert_equal(executable, actual.first)
-          refute_includes(actual, "--postcss config/postcss.config.js")
+          refute_includes(actual, "--postcss")
 
           config_file = Rails.root.join("config/postcss.config.js")
           FileUtils.mkdir_p(Rails.root.join("config"))
           FileUtils.touch(config_file)
           actual = Tailwindcss::Commands.compile_command(exe_path: dir)
           assert_kind_of(Array, actual)
           assert_equal(executable, actual.first)
-          assert_includes(actual, "--postcss #{config_file}")
+          assert_includes(actual, "--postcss")
+          postcss_index = actual.index("--postcss")
+          assert_equal(actual[postcss_index + 1], config_file.to_s)
         end
       end
     end