Merge pull request #52 from lxxxvi/add-output-flag

basics for `--output`

README.md

@@ -89,13 +89,14 @@ ruboclean [path] [--silent] [--preserve-comments] [--preserve-paths] [--verify]
 
 ### Parameters
 
-| Parameter             | Description                                                                                                                           |
-|:----------------------|:--------------------------------------------------------------------------------------------------------------------------------------|
-| `path`                | Can be a directory that contains a `.rubocop.yml`, or a path to a `.rubocop.yml` directly. Defaults to the current working directory. |
-| `--silent`            | Suppress any output displayed on the screen when executing the command.                                                               |
-| `--preserve-comments` | Preserves **preceding** comments for each top-level entry in the configuration. Inline comments are **not** preserved.                |
-| `--preserve-paths`    | Skips the path cleanup that are applied against `Include:` and `Exclude:` configuration.                                              |
-| `--verify`            | Executes in dry-run mode. Exits with 1 if changes are needed, otherwise 0.                                                            |
+| Parameter                        | Description                                                                                                                           |
+|:---------------------------------|:--------------------------------------------------------------------------------------------------------------------------------------|
+| `path`                           | Can be a directory that contains a `.rubocop.yml`, or a path to a `.rubocop.yml` directly. Defaults to the current working directory. |
+| `--output=[/path/to/output.yml]` | Output path, where the result is written to. Can be either absolute or relative of the current working directory                      |
+| `--silent`                       | Suppress any output displayed on the screen when executing the command.                                                               |
+| `--preserve-comments`            | Preserves **preceding** comments for each top-level entry in the configuration. Inline comments are **not** preserved.                |
+| `--preserve-paths`               | Skips the path cleanup that are applied against `Include:` and `Exclude:` configuration.                                              |
+| `--verify`                       | Executes in dry-run mode. Exits with 1 if changes are needed, otherwise 0.                                                            |
 
 ### Examples
 

lib/ruboclean/cli_arguments.rb

@@ -3,6 +3,14 @@
 module Ruboclean
   # Reads command line arguments and exposes corresponding reader methods
   class CliArguments
+    FLAG_DEFAULTS = {
+      "--output" => nil,
+      "--silent" => false,
+      "--preserve-comments" => false,
+      "--preserve-paths" => false,
+      "--verify" => false
+    }.freeze
+
     def initialize(command_line_arguments = [])
       @command_line_arguments = Array(command_line_arguments)
     end
@@ -11,24 +19,28 @@ def path
       @path ||= find_path
     end
 
+    def output_path
+      flag_arguments.fetch("--output")
+    end
+
     def verbose?
       !silent?
     end
 
     def silent?
-      @silent ||= find_argument("--silent")
+      flag_arguments.fetch("--silent")
     end
 
     def preserve_comments?
-      @preserve_comments ||= find_argument("--preserve-comments")
+      flag_arguments.fetch("--preserve-comments")
     end
 
     def preserve_paths?
-      @preserve_paths ||= find_argument("--preserve-paths")
+      flag_arguments.fetch("--preserve-paths")
     end
 
     def verify?
-      @verify ||= find_argument("--verify")
+      flag_arguments.fetch("--verify")
     end
 
     private
@@ -43,8 +55,25 @@ def find_path
       end
     end
 
-    def find_argument(name)
-      command_line_arguments.any? { |argument| argument == name }
+    def flag_arguments
+      @flag_arguments ||= FLAG_DEFAULTS.dup.merge(custom_flag_arguments)
+    end
+
+    def custom_flag_arguments
+      command_line_arguments.each_with_object({}) do |item, hash|
+        next unless item.start_with?("--")
+
+        flag_name, flag_value = item.split("=")
+
+        raise ArgumentError, "invalid argument '#{item}'" unless FLAG_DEFAULTS.include?(flag_name)
+
+        flag_default_value = FLAG_DEFAULTS[flag_name]
+
+        hash[flag_name] = flag_value
+
+        # Subject to change: We may need to find another way to determine if an argument has Boolean characteristics
+        hash[flag_name] = !flag_value if flag_default_value.is_a?(FalseClass)
+      end
     end
   end
 end

lib/ruboclean/runner.rb

@@ -64,14 +64,18 @@ def convert_to_yaml(configuration_hash)
 
     def write_file!(target_yaml)
       target_yaml.tap do |content|
-        source_file_pathname.write(content) unless verify?
+        target_file_pathname.write(content) unless verify?
       end
     end
 
     def source_file_pathname
       @source_file_pathname ||= find_source_file_pathname
     end
 
+    def target_file_pathname
+      @target_file_pathname ||= find_target_file_pathname
+    end
+
     def find_source_file_pathname
       source_path = Pathname.new(cli_arguments.path)
 
@@ -81,5 +85,16 @@ def find_source_file_pathname
 
       raise ArgumentError, "path does not exist: '#{source_path}'"
     end
+
+    def find_target_file_pathname
+      return source_file_pathname if cli_arguments.output_path.nil?
+
+      target_path = Pathname.new(cli_arguments.output_path)
+      target_path = Pathname.new(Dir.pwd).join(target_path) if target_path.relative?
+
+      return target_path unless target_path.directory?
+
+      raise ArgumentError, "output path (--output=#{target_path}) cannot be a directory"
+    end
   end
 end

test/ruboclean/cli_arguments_test.rb

@@ -4,12 +4,14 @@
 
 module Ruboclean
   class ArgumentsTest < BaseTest
-    def test_path_defaults
+    def test_path_defaults # rubocop:disable Minitest/MultipleAssertions
       Ruboclean::CliArguments.new.tap do |cli_arguments|
         assert_equal Dir.pwd.to_s, cli_arguments.path
+        assert_nil cli_arguments.output_path
         assert_predicate cli_arguments, :verbose?
         refute_predicate cli_arguments, :silent?
         refute_predicate cli_arguments, :preserve_comments?
+        refute_predicate cli_arguments, :preserve_paths?
         refute_predicate cli_arguments, :verify?
       end
     end
@@ -18,6 +20,13 @@ def test_path_custom
       assert_equal "foo/bar.yml", Ruboclean::CliArguments.new(["foo/bar.yml"]).path
     end
 
+    def test_output_path_custom
+      Ruboclean::CliArguments.new(["--output=/foo/bar"]).tap do |cli_arguments|
+        assert_equal Dir.pwd.to_s, cli_arguments.path
+        assert_equal "/foo/bar", cli_arguments.output_path
+      end
+    end
+
     def test_silent_custom
       Ruboclean::CliArguments.new(["--silent"]).tap do |cli_arguments|
         assert_equal Dir.pwd.to_s, cli_arguments.path

test/ruboclean/runner_test.rb

@@ -3,7 +3,7 @@
 require "test_helper"
 
 module Ruboclean
-  class RunnerTest < BaseTest
+  class RunnerTest < BaseTest # rubocop:disable Metrics/ClassLength
     def test_run_without_arguments
       using_fixture_files("00_input.yml") do |fixture_path, directory_path|
         changed = Dir.chdir(directory_path) do
@@ -88,6 +88,72 @@ def test_run_without_require_block
       end
     end
 
+    def test_run_with_output_argument_absolute_path
+      using_fixture_files("00_input.yml") do |fixture_path|
+        output_pathname = Pathname.new(fixture_path).dirname.join("custom_output_path.yml")
+        arguments = [fixture_path, "--output=#{output_pathname}"]
+        Ruboclean::Runner.new(arguments).run!
+
+        assert_predicate output_pathname, :exist?
+
+        assert_equal(
+          fixture_file_path("00_expected_output.yml").read,
+          output_pathname.read
+        )
+      end
+    end
+
+    def test_run_with_output_argument_relative_path # rubocop:disable Metrics/MethodLength
+      # we need to read it here, because we're leaving the working directory soon
+      expected_target_file_content = fixture_file_path("00_expected_output.yml").read
+
+      using_fixture_files("00_input.yml") do |fixture_path|
+        Dir.mktmpdir do |tmpdir|
+          Dir.chdir(tmpdir) do
+            arguments = [fixture_path, "--output=relative_path.yml"]
+
+            Ruboclean::Runner.new(arguments).run!
+
+            output_pathname = Pathname.new(tmpdir).join("relative_path.yml")
+
+            assert_predicate output_pathname, :exist?
+            assert_equal expected_target_file_content,
+                         output_pathname.read
+          end
+        end
+      end
+    end
+
+    def test_run_with_output_argument_overrides_a_file
+      using_fixture_files("00_input.yml") do |fixture_path|
+        output_pathname = Pathname.new(fixture_path).dirname.join("custom_output_path.yml")
+        arguments = [fixture_path, "--output=#{output_pathname}"]
+        output_pathname.write("file content before")
+
+        Ruboclean::Runner.new(arguments).run!
+
+        assert_equal(
+          fixture_file_path("00_expected_output.yml").read,
+          output_pathname.read
+        )
+      end
+    end
+
+    def test_run_with_output_argument_raises_if_target_exists_as_directory
+      using_fixture_files("00_input.yml") do |fixture_path|
+        output_pathname = Pathname.new(fixture_path).dirname.join("some_directory")
+        arguments = [fixture_path, "--output=#{output_pathname}"]
+        output_pathname.mkdir
+
+        error = assert_raises ArgumentError do
+          Ruboclean::Runner.new(arguments).run!
+        end
+
+        assert_equal "output path (--output=#{output_pathname}) cannot be a directory",
+                     error.message
+      end
+    end
+
     def test_run_with_preserve_comments_flag
       using_fixture_files("00_input.yml") do |fixture_path|
         arguments = [fixture_path, "--preserve-comments"]