feat: add RuboCop linter support for Ruby

README.md

@@ -48,6 +48,7 @@ Linters which are not language-specific:
 | Markdown               | [Prettier]                | [Vale]                           |
 | Protocol Buffer        | [buf]                     | [buf lint]                       |
 | Python                 | [ruff]                    | [flake8], [pylint], [ruff]       |
+| Ruby                   |                           | [RuboCop]                        |
 | Rust                   | [rustfmt]                 |                                  |
 | SQL                    | [prettier-plugin-sql]     |                                  |
 | Scala                  | [scalafmt]                |                                  |
@@ -83,6 +84,7 @@ Linters which are not language-specific:
 [gofumpt]: https://github.com/mvdan/gofumpt
 [jsonnetfmt]: https://github.com/google/go-jsonnet
 [scalafmt]: https://scalameta.org/scalafmt
+[rubocop]: https://docs.rubocop.org/
 [ruff]: https://docs.astral.sh/ruff/
 [pylint]: https://pylint.readthedocs.io/en/stable/
 [shellcheck]: https://www.shellcheck.net/

example/.bazelrc

@@ -1,5 +1,5 @@
 import %workspace%/../tools/preset.bazelrc
-import %workspace%/tools/java17.bazelrc
+import %workspace%/tools/java21.bazelrc
 
 # Automatically apply --config=linux, --config=windows etc
 common --enable_platform_specific_config

example/.rubocop.yml

@@ -0,0 +1,24 @@
+# RuboCop configuration for rules_lint example
+
+AllCops:
+  NewCops: enable
+  TargetRubyVersion: 3.0
+
+# Configure line length
+Layout/LineLength:
+  Max: 100
+
+# Enable some common cops for demonstration
+Style/StringLiterals:
+  Enabled: true
+  EnforcedStyle: single_quotes
+
+Style/TrailingCommaInArrayLiteral:
+  Enabled: true
+  EnforcedStyleForMultiline: consistent_comma
+
+Lint/UselessAssignment:
+  Enabled: true
+
+Style/DoubleNegation:
+  Enabled: true

example/.ruby-version

@@ -0,0 +1 @@
+jruby-10.0.2.0

example/BUILD.bazel

@@ -20,6 +20,7 @@ exports_files(
         "checkstyle.xml",
         "checkstyle-suppressions.xml",
         ".ruff.toml",
+        ".rubocop.yml",
         ".shellcheckrc",
         ".scalafmt.conf",
         ".swcrc",

example/Gemfile

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+source 'https://rubygems.org'
+
+gem 'rubocop', '~> 1.50'

example/Gemfile.lock

@@ -0,0 +1,47 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    ast (2.4.3)
+    json (2.15.1)
+    json (2.15.1-java)
+    language_server-protocol (3.17.0.5)
+    lint_roller (1.1.0)
+    parallel (1.27.0)
+    parser (3.3.9.0)
+      ast (~> 2.4.1)
+      racc
+    prism (1.5.2)
+    racc (1.8.1)
+    racc (1.8.1-java)
+    rainbow (3.1.1)
+    regexp_parser (2.11.3)
+    rubocop (1.81.1)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (~> 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.47.1, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.47.1)
+      parser (>= 3.3.7.2)
+      prism (~> 1.4)
+    ruby-progressbar (1.13.0)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.1.0)
+
+PLATFORMS
+  arm64-darwin-24
+  ruby
+  universal-java
+  universal-java-21
+
+DEPENDENCIES
+  rubocop (~> 1.50)
+
+BUNDLED WITH
+   2.6.9

example/MODULE.bazel

@@ -19,6 +19,7 @@ bazel_dep(name = "rules_go", version = "0.52.0", repo_name = "io_bazel_rules_go"
 bazel_dep(name = "rules_proto", version = "6.0.0")
 bazel_dep(name = "rules_python", version = "0.26.0")
 bazel_dep(name = "rules_rust", version = "0.50.1")
+bazel_dep(name = "rules_ruby", version = "0.21.1")
 bazel_dep(name = "buildifier_prebuilt", version = "6.3.3")
 bazel_dep(name = "platforms", version = "0.0.8")
 bazel_dep(name = "rules_kotlin", version = "1.9.0")
@@ -128,3 +129,36 @@ rust.toolchain(
     edition = "2021",
     versions = ["1.75.0"],
 )
+
+ruby = use_extension("@rules_ruby//ruby:extensions.bzl", "ruby")
+ruby.toolchain(
+    name = "ruby",
+    version_file = "//:.ruby-version",
+)
+ruby.bundle_fetch(
+    name = "bundle",
+    gem_checksums = {
+        "ast-2.4.3": "954615157c1d6a382bc27d690d973195e79db7f55e9765ac7c481c60bdb4d383",
+        "json-2.15.1": "b1c1b2e7c116eb1903e0ce0c374783e6ead8747a0f9eca132d274018ebb80b89",
+        "json-2.15.1-java": "a6185eebe724a6937f60729e4998276d6b3de3ecc35be34f8e47c1eb40903ecf",
+        "language_server-protocol-3.17.0.5": "fd1e39a51a28bf3eec959379985a72e296e9f9acfce46f6a79d31ca8760803cc",
+        "lint_roller-1.1.0": "2c0c845b632a7d172cb849cc90c1bce937a28c5c8ccccb50dfd46a485003cc87",
+        "parallel-1.27.0": "4ac151e1806b755fb4e2dc2332cbf0e54f2e24ba821ff2d3dcf86bf6dc4ae130",
+        "parser-3.3.9.0": "94d6929354b1a6e3e1f89d79d4d302cc8f5aa814431a6c9c7e0623335d7687f2",
+        "prism-1.5.2": "192741663a55af1ac1b987caa1092deb666e4ff46a30c5064ad5456acd05df1d",
+        "racc-1.8.1": "4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f",
+        "racc-1.8.1-java": "54f2e6d1e1b91c154013277d986f52a90e5ececbe91465d29172e49342732b98",
+        "rainbow-3.1.1": "039491aa3a89f42efa1d6dec2fc4e62ede96eb6acd95e52f1ad581182b79bc6a",
+        "regexp_parser-2.11.3": "ca13f381a173b7a93450e53459075c9b76a10433caadcb2f1180f2c741fc55a4",
+        "rubocop-1.81.1": "352a9a6f314a4312f6c305f1f72bc466254d221c95445cd49e1b65d1f9411635",
+        "rubocop-ast-1.47.1": "592682017855408b046a8190689490763aecea175238232b1b526826349d01ae",
+        "ruby-progressbar-1.13.0": "80fc9c47a9b640d6834e0dc7b3c94c9df37f08cb072b7761e4a71e22cff29b33",
+        "unicode-display_width-3.2.0": "0cdd96b5681a5949cdbc2c55e7b420facae74c4aaf9a9815eee1087cb1853c42",
+        "unicode-emoji-4.1.0": "4997d2d5df1ed4252f4830a9b6e86f932e2013fbff2182a9ce9ccabda4f325a5",
+    },
+    gemfile = "//:Gemfile",
+    gemfile_lock = "//:Gemfile.lock",
+)
+use_repo(ruby, "bundle", "ruby", "ruby_toolchains")
+
+register_toolchains("@ruby_toolchains//:all")

example/WORKSPACE.bazel

@@ -334,6 +334,44 @@ register_sarif_parser_toolchains(
     register = True,
 )
 
+http_archive(
+    name = "rules_ruby",
+    sha256 = "305d299056a586e24022651eccfe172ea1754121ea79c637e29fc1c42704ae3c",
+    strip_prefix = "rules_ruby-0.21.1",
+    url = "https://github.com/bazel-contrib/rules_ruby/releases/download/v0.21.1/rules_ruby-v0.21.1.tar.gz",
+)
+
+load("@rules_ruby//ruby:deps.bzl", "rb_bundle_fetch", "rb_register_toolchains")
+
+rb_register_toolchains(
+    version_file = "//:.ruby-version",
+)
+
+rb_bundle_fetch(
+    name = "bundle",
+    gem_checksums = {
+        "ast-2.4.3": "954615157c1d6a382bc27d690d973195e79db7f55e9765ac7c481c60bdb4d383",
+        "json-2.15.1": "b1c1b2e7c116eb1903e0ce0c374783e6ead8747a0f9eca132d274018ebb80b89",
+        "json-2.15.1-java": "a6185eebe724a6937f60729e4998276d6b3de3ecc35be34f8e47c1eb40903ecf",
+        "language_server-protocol-3.17.0.5": "fd1e39a51a28bf3eec959379985a72e296e9f9acfce46f6a79d31ca8760803cc",
+        "lint_roller-1.1.0": "2c0c845b632a7d172cb849cc90c1bce937a28c5c8ccccb50dfd46a485003cc87",
+        "parallel-1.27.0": "4ac151e1806b755fb4e2dc2332cbf0e54f2e24ba821ff2d3dcf86bf6dc4ae130",
+        "parser-3.3.9.0": "94d6929354b1a6e3e1f89d79d4d302cc8f5aa814431a6c9c7e0623335d7687f2",
+        "prism-1.5.2": "192741663a55af1ac1b987caa1092deb666e4ff46a30c5064ad5456acd05df1d",
+        "racc-1.8.1": "4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f",
+        "racc-1.8.1-java": "54f2e6d1e1b91c154013277d986f52a90e5ececbe91465d29172e49342732b98",
+        "rainbow-3.1.1": "039491aa3a89f42efa1d6dec2fc4e62ede96eb6acd95e52f1ad581182b79bc6a",
+        "regexp_parser-2.11.3": "ca13f381a173b7a93450e53459075c9b76a10433caadcb2f1180f2c741fc55a4",
+        "rubocop-1.81.1": "352a9a6f314a4312f6c305f1f72bc466254d221c95445cd49e1b65d1f9411635",
+        "rubocop-ast-1.47.1": "592682017855408b046a8190689490763aecea175238232b1b526826349d01ae",
+        "ruby-progressbar-1.13.0": "80fc9c47a9b640d6834e0dc7b3c94c9df37f08cb072b7761e4a71e22cff29b33",
+        "unicode-display_width-3.2.0": "0cdd96b5681a5949cdbc2c55e7b420facae74c4aaf9a9815eee1087cb1853c42",
+        "unicode-emoji-4.1.0": "4997d2d5df1ed4252f4830a9b6e86f932e2013fbff2182a9ce9ccabda4f325a5",
+    },
+    gemfile = "//:Gemfile",
+    gemfile_lock = "//:Gemfile.lock",
+)
+
 #---SNIP--- Below here is re-used in the workspace snippet published on releases
 
 load(

example/src/BUILD.bazel

@@ -6,6 +6,7 @@ load("@io_bazel_rules_go//go:def.bzl", "go_binary")
 load("@rules_kotlin//kotlin:jvm.bzl", "kt_jvm_library")
 load("@rules_proto//proto:defs.bzl", "proto_library")
 load("@rules_python//python:defs.bzl", "py_library")
+load("@rules_ruby//ruby:defs.bzl", "rb_library")
 load("@rules_shell//shell:sh_library.bzl", "sh_library")
 load("//tools/lint:linters.bzl", "eslint_test")
 
@@ -40,6 +41,11 @@ filegroup(
     tags = ["toml"],
 )
 
+rb_library(
+    name = "hello_ruby",
+    srcs = ["hello.rb"],
+)
+
 ts_project(
     name = "ts_dep",
     srcs = ["file-dep.ts"],

example/src/hello.rb

@@ -0,0 +1,38 @@
+# Demo file showing RuboCop violations
+
+# Unused variable (will be caught by RuboCop)
+unused_variable = "not used"
+
+# Line too long - this is a demonstration of a line that exceeds the maximum line length configured in .rubocop.yml
+def example_method_with_very_long_line
+  puts "This is an example of a line that is intentionally too long and should be flagged by RuboCop for exceeding the maximum line length"
+end
+
+# Missing frozen string literal comment (if configured)
+class ExampleClass
+  def initialize(name)
+    @name = name
+  end
+
+  # Method with trailing whitespace and inconsistent indentation
+  def greet
+      puts "Hello, #{@name}!"
+  end
+
+  # Double negation (style issue)
+  def active?
+    !!@active
+  end
+end
+
+# Prefer single quotes over double quotes for static strings
+message = "Hello world"
+
+# Trailing comma missing in multi-line array
+numbers = [
+  1,
+  2,
+  3
+]
+
+puts ExampleClass.new("World").greet

example/test/BUILD.bazel

@@ -5,7 +5,17 @@ load("@aspect_rules_ts//ts:defs.bzl", "ts_project")
 load("@bazel_skylib//rules:write_file.bzl", "write_file")
 load("@rules_python//python:defs.bzl", "py_library")
 load("@rules_shell//shell:sh_library.bzl", "sh_library")
-load("//tools/lint:linters.bzl", "checkstyle_test", "eslint_test", "flake8_test", "pmd_test", "pylint_test", "ruff_test", "shellcheck_test")
+load(
+    "//tools/lint:linters.bzl",
+    "checkstyle_test",
+    "eslint_test",
+    "flake8_test",
+    "pmd_test",
+    "pylint_test",
+    "rubocop_test",
+    "ruff_test",
+    "shellcheck_test",
+)
 
 write_file(
     name = "ts_code_generator",
@@ -176,3 +186,11 @@ format_test(
     srcs = [":generated_sh"],
     tags = ["manual"],
 )
+
+rubocop_test(
+    name = "rubocop",
+    srcs = ["//src:hello_ruby"],
+    # Expected to fail based on current content of the file.
+    # Normally you'd fix the file instead of tagging this test.
+    tags = ["manual"],
+)

example/test/lint_test.bats

@@ -62,6 +62,13 @@ EOF
                first-person plural like 'We'.
 EOF
 
+	# RuboCop
+	echo <<"EOF" | assert_output --partial
+C:  1:  1: [Correctable] Style/FrozenStringLiteralComment: Missing frozen string literal comment.
+W:  4:  1: [Correctable] Lint/UselessAssignment: Useless assignment to variable - unused_variable.
+C:  6:101: Layout/LineLength: Line is too long. [115/100]
+EOF
+
 	# stylelint
 	echo <<"EOF" | assert_output --partial
 src/hello.css

example/tools/java17.bazelrc → example/tools/java21.bazelrc

@@ -4,17 +4,17 @@
 
 # What version of Java are the source files in this repo?
 # See https://bazel.build/docs/user-manual#java-language-version
-common --java_language_version=17
+common --java_language_version=21
 
 # The Java language version used to build tools that are executed during a build
 # See https://bazel.build/docs/user-manual#tool-java-language-version
-common --tool_java_language_version=17
+common --tool_java_language_version=21
 
 # The version of JVM to use to execute the code and run the tests.
 # NB: The default value is local_jdk which is non-hermetic.
 # See https://bazel.build/docs/user-manual#java-runtime-version
-common --java_runtime_version=remotejdk_17
+common --java_runtime_version=remotejdk_21
 
 # The version of JVM used to execute tools that are needed during a build.
 # See https://bazel.build/docs/user-manual#tool-java-runtime-version
-common --tool_java_runtime_version=remotejdk_17
+common --tool_java_runtime_version=remotejdk_21

example/tools/lint/BUILD.bazel

@@ -114,3 +114,8 @@ native_binary(
     ),
     out = "clang_tidy",
 )
+
+alias(
+    name = "rubocop",
+    actual = "@bundle//bin:rubocop",
+)

example/tools/lint/linters.bzl

@@ -9,6 +9,7 @@ load("@aspect_rules_lint//lint:keep_sorted.bzl", "lint_keep_sorted_aspect")
 load("@aspect_rules_lint//lint:ktlint.bzl", "lint_ktlint_aspect")
 load("@aspect_rules_lint//lint:lint_test.bzl", "lint_test")
 load("@aspect_rules_lint//lint:pmd.bzl", "lint_pmd_aspect")
+load("@aspect_rules_lint//lint:rubocop.bzl", "lint_rubocop_aspect")
 load("@aspect_rules_lint//lint:ruff.bzl", "lint_ruff_aspect")
 load("@aspect_rules_lint//lint:pylint.bzl", "lint_pylint_aspect")
 load("@aspect_rules_lint//lint:shellcheck.bzl", "lint_shellcheck_aspect")
@@ -142,3 +143,10 @@ keep_sorted = lint_keep_sorted_aspect(
 )
 
 keep_sorted_test = lint_test(aspect = keep_sorted)
+
+rubocop = lint_rubocop_aspect(
+    binary = Label("//tools/lint:rubocop"),
+    configs = [Label("//:.rubocop.yml")],
+)
+
+rubocop_test = lint_test(aspect = rubocop)

lint/BUILD.bazel

@@ -199,6 +199,12 @@ bzl_library(
     ],
 )
 
+bzl_library(
+    name = "rubocop",
+    srcs = ["rubocop.bzl"],
+    deps = ["//lint/private:lint_aspect"],
+)
+
 bzl_library(
     name = "ruff",
     srcs = ["ruff.bzl"],