diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..5154b3f
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+2.6
diff --git a/Dangerfile b/Dangerfile
new file mode 100644
index 0000000..af24e3e
--- /dev/null
+++ b/Dangerfile
@@ -0,0 +1,82 @@
+#
+# GitHub Comment
+#
+github.dismiss_out_of_range_messages({
+  error: false,
+  warning: true,
+  message: true,
+  markdown: true
+})
+
+#
+# File watching
+#
+
+[
+  ".idea/codeStyleSettings.xml",
+].each do |file|
+  warn("Are you sure want to modify #{file} ?") if git.modified_files.include?(file)
+end
+
+#
+# Compiler warnings, errors
+#
+
+warning_pattern = /w: (?<path>(?:\/.+)+\.kt): \((?<line>\d+), (?<column>\d+)\): (?<description>.*)/
+error_pattern = /e: (?<path>(?:\/.+)+\.kt): \((?<line>\d+), (?<column>\d+)\): (?<description>.*)/
+
+target_files = (git.modified_files - git.deleted_files) + git.added_files
+kotlin_compile_files = Dir.glob("**/build/kotlin/compile*Kotlin*.stdout")
+unless kotlin_compile_files.empty?
+  compile_messages = File.read(kotlin_compile_files.first).strip
+    .split("\n")
+    .each { |s|
+      if match = s.match(warning_pattern)
+        file = Pathname(match[:path]).relative_path_from(Pathname(Dir.pwd)).to_s
+        if git.diff_for_file(file)
+          warn("#{match[:description]}", file: file, line: match[:line].to_i)
+        else
+          warn("#{file}: (#{match[:line]}, #{match[:column]}): #{match[:description]}")
+        end
+      end
+      if match = s.match(error_pattern)
+        file = Pathname(match[:path]).relative_path_from(Pathname(Dir.pwd)).to_s
+        if git.diff_for_file(file)
+          fail("#{match[:description]}", file: file, line: match[:line].to_i)
+        else
+          fail("#{file}: (#{match[:line]}, #{match[:column]}): #{match[:description]}")
+        end
+      end
+    }
+end
+
+#
+# ktlint
+#
+checkstyle_format.base_path = Dir.pwd
+Dir.glob('**/build/reports/ktlint/ktlint*Check.xml') do |file|
+  checkstyle_format.report file
+end
+
+#
+# JUnit test results
+#
+
+tests = []
+failures = []
+errors = []
+skipped = []
+
+Dir.glob("**/build/test-results/**/TEST-*.xml") do |file|
+  junit.parse file
+  tests.concat(junit.tests)
+  failures.concat(junit.failures)
+  errors.concat(junit.errors)
+  skipped.concat(junit.skipped)
+end
+junit.tests = tests
+junit.failures = failures
+junit.errors = errors
+junit.skipped = skipped
+
+junit.report
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..2b62d4d
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+
+gem 'danger'
+gem 'danger-junit'
+gem 'danger-checkstyle_format'
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..2bede9e
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,70 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    claide (1.0.3)
+    claide-plugins (0.9.2)
+      cork
+      nap
+      open4 (~> 1.3)
+    colored2 (3.1.2)
+    cork (0.3.0)
+      colored2 (~> 3.1)
+    danger (7.0.0)
+      claide (~> 1.0)
+      claide-plugins (>= 0.9.2)
+      colored2 (~> 3.1)
+      cork (~> 0.1)
+      faraday (>= 0.9.0, < 2.0)
+      faraday-http-cache (~> 2.0)
+      git (~> 1.6)
+      kramdown (~> 2.0)
+      kramdown-parser-gfm (~> 1.0)
+      no_proxy_fix
+      octokit (~> 4.7)
+      terminal-table (~> 1)
+    danger-checkstyle_format (0.1.1)
+      danger-plugin-api (~> 1.0)
+      ox (~> 2.0)
+    danger-junit (1.0.0)
+      danger (> 2.0)
+      ox (~> 2.0)
+    danger-plugin-api (1.0.0)
+      danger (> 2.0)
+    faraday (1.0.1)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (2.2.0)
+      faraday (>= 0.8)
+    git (1.6.0)
+      rchardet (~> 1.8)
+    kramdown (2.1.0)
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
+    multipart-post (2.1.1)
+    nap (1.1.0)
+    no_proxy_fix (0.1.2)
+    octokit (4.18.0)
+      faraday (>= 0.9)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    open4 (1.3.4)
+    ox (2.13.2)
+    public_suffix (4.0.4)
+    rchardet (1.8.0)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
+    terminal-table (1.8.0)
+      unicode-display_width (~> 1.1, >= 1.1.1)
+    unicode-display_width (1.7.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  danger
+  danger-checkstyle_format
+  danger-junit
+
+BUNDLED WITH
+   2.1.4