Add JSON output format option to rails stats command

railties/CHANGELOG.md

@@ -1,3 +1,33 @@
+*   Add JSON output format to `rails stats` via `format` option.
+
+    Enables JSON formatted output for better integration with automated systems. Maintains default table format unless specified.
+
+    ```shell
+    $ bin/rails stats[json] | jq .
+    {
+      "code_statistics": [
+        {
+          "name": "Controllers",
+          "statistic": {
+            "lines": 12345,
+            "code_lines": 12345,
+            "classes": 123,
+            "methods": 1234
+          }
+        },
+        ...
+      ],
+      "total": {
+        "lines": 12345,
+        "code_lines": 12345,
+        "classes": 123,
+        "methods": 1234
+      }
+    }
+    ```
+
+    *Teppei Shintani*
+
 *   Allow Actionable Errors encountered when running tests to be retried.
 
     ```txt

railties/lib/rails/code_statistics.rb

@@ -35,6 +35,18 @@ def to_s
     print_code_test_stats
   end
 
+  def to_h
+    {
+      code_statistics: @statistics.map do |k, v|
+        {
+          name: k,
+          statistic: v.to_h
+        }
+      end,
+      total: @total&.to_h
+    }
+  end
+
   private
     def calculate_statistics
       Hash[@pairs.map { |pair| [pair.first, calculate_directory_statistics(pair.last)] }]

railties/lib/rails/code_statistics_calculator.rb

@@ -86,6 +86,15 @@ def add_by_io(io, file_type)
     end
   end
 
+  def to_h
+    {
+      lines: lines,
+      code_lines: code_lines,
+      classes: classes,
+      methods: methods
+    }
+  end
+
   private
     def file_type(file_path)
       if file_path.end_with? "_test.rb"

railties/lib/rails/tasks/statistics.rake

@@ -29,10 +29,16 @@ STATS_DIRECTORIES ||= [
 ]
 
 desc "Report code statistics (KLOCs, etc) from the application or engine"
-task :stats do
+task :stats, :format do |_, args|
   require "rails/code_statistics"
   stat_directories = STATS_DIRECTORIES.collect do |name, dir|
     [ name, "#{File.dirname(Rake.application.rakefile_location)}/#{dir}" ]
   end.select { |name, dir| File.directory?(dir) }
-  CodeStatistics.new(*stat_directories).to_s
+  statistics = CodeStatistics.new(*stat_directories)
+  case args[:format]
+  when "json"
+    puts statistics.to_h.to_json
+  else
+    statistics.to_s
+  end
 end

railties/test/code_statistics_calculator_test.rb

@@ -84,6 +84,11 @@ class A; end
     assert_equal 6, @code_statistics_calculator.methods
   end
 
+  test "return statistics as a hash" do
+    code_statistics_calculator = CodeStatisticsCalculator.new(1, 2, 3, 4)
+    assert_equal({ lines: 1, code_lines: 2, classes: 3, methods: 4 }, code_statistics_calculator.to_h)
+  end
+
   test "calculate number of Ruby methods" do
     code = <<-'CODE'
       def foo

railties/test/code_statistics_test.rb

@@ -31,4 +31,59 @@ def foo
       CodeStatistics.new(["hidden file", @tmp_path])
     end
   end
+
+  test "output results in table format" do
+    File.write File.join(@tmp_path, "example.rb"), <<-CODE
+      class Example
+        def foo
+          puts 'foo'
+        end
+      end
+    CODE
+
+    code_statistics = CodeStatistics.new(["tmp dir", @tmp_path])
+    expected = <<~TABLE
+      +----------------------+--------+--------+---------+---------+-----+-------+
+      | Name                 |  Lines |    LOC | Classes | Methods | M/C | LOC/M |
+      +----------------------+--------+--------+---------+---------+-----+-------+
+      | tmp dir              |      5 |      5 |       1 |       1 |   1 |     3 |
+      +----------------------+--------+--------+---------+---------+-----+-------+
+        Code LOC: 5     Test LOC: 0     Code to Test Ratio: 1:0.0
+
+    TABLE
+
+    output, _ = capture_io do
+      code_statistics.to_s
+    end
+
+    assert_equal expected, output
+  end
+
+  test "return results in hash format" do
+    File.write File.join(@tmp_path, "example.rb"), <<-CODE
+      class Example
+        def foo
+          puts 'foo'
+        end
+      end
+    CODE
+
+    code_statistics = CodeStatistics.new(["tmp dir", @tmp_path])
+    expected = {
+      code_statistics: [
+        {
+          name: "tmp dir",
+          statistic: {
+            lines: 5,
+            code_lines: 5,
+            classes: 1,
+            methods: 1
+          }
+        }
+      ],
+      total: nil
+    }
+
+    assert_equal expected, code_statistics.to_h
+  end
 end