golangci2checkstyle.rb

#!/usr/bin/env ruby

# Input:
# {
#   "Issues": [
#     {
#       "FromLinter": "gofmt",
#       "Text": "File is not `gofmt`-ed with `-s`",
#       "Pos": {
#         "Filename": "shell/shell.go",
#         "Offset": 0,
#         "Line": 9,
#         "Column": 0
#       },
#       "SourceLines": [
#         "\t\"github.com/sirupsen/logrus\""
#       ],
#       "Replacement": {
#         "NeedOnlyDelete": true,
#         "NewLines": null
#       }
#     }
#   ]
# }
#
# Output:
# <?xml version="1.0" encoding="UTF-8"?>
# <checkstyle version="5.0">
#     <file name="shell/shell.go">
#         <error column="0" line="9" message='File is not `gofmt`-ed with `-s`' severity="warning" source="gofmt">
#         </error>
#     </file>
# </checkstyle>

require 'fcntl'
require 'json'
require "rexml/document"

module GoLangCIToCheckstyle
  class << self
    def call
      raise "Usage: #$0 < golangci-lint-output.json" unless STDIN.fcntl(Fcntl::F_GETFL, 0) == 0
      puts translate(ARGF.read)
    end

    def translate(input)
      json = JSON.parse(input)

      xml = REXML::Document.new
      root = xml.add_element('checkstyle', 'version' => 5.0)

      files = Hash.new { |h, k| h[k] = [] }
      (json["Issues"] || []).each do |line|
        files[line["Pos"]["Filename"]] << line
      end

      files.each do |file, lines|
        file_el = root.add_element('file', 'name' => file)
        lines.each do |line|
          file_el.add_element('error',
            'line' => line['Pos']['Line'],
            'column' => line['Pos']['Column'],
            'message' => line['Text'],
            'severity' => 'warning',
            'source' => line['FromLinter'],
          )
        end
      end

      io = StringIO.new
      xml.write(REXML::Output.new(io, "UTF-8"))
      io.string
    end
  end
end

__FILE__ == $PROGRAM_NAME and GoLangCIToCheckstyle.call