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rubocop - GitHub

Configuration in Mega-Linter

Variable Description Default value
RUBY_RUBOCOP_ARGUMENTS User custom arguments to add in linter CLI call
Ex: -s --foo "bar"
RUBY_RUBOCOP_FILTER_REGEX_INCLUDE Custom regex including filter
Ex: (src\|lib)
Include every file
RUBY_RUBOCOP_FILTER_REGEX_EXCLUDE Custom regex excluding filter
Ex: (test\|examples)
Exclude no file
RUBY_RUBOCOP_CLI_LINT_MODE Override default CLI lint mode
- file: Calls the linter for each file
- list_of_files: Call the linter with the list of files as argument
- project: Call the linter from the root of the project
RUBY_RUBOCOP_FILE_EXTENSIONS Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all files
Ex: [".py", ""]
RUBY_RUBOCOP_FILE_NAMES_REGEX File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files
Ex: ["Dockerfile(-.+)?", "Jenkinsfile"]
Include every file
RUBY_RUBOCOP_PRE_COMMANDS List of bash commands to run before the linter None
RUBY_RUBOCOP_POST_COMMANDS List of bash commands to run after the linter None
RUBY_RUBOCOP_CONFIG_FILE rubocop configuration file name
Use LINTER_DEFAULT to let the linter find it
RUBY_RUBOCOP_RULES_PATH Path where to find linter configuration file Workspace folder, then Mega-Linter default rules
RUBY_RUBOCOP_DISABLE_ERRORS Run linter but consider errors as warnings false
RUBY_RUBOCOP_DISABLE_ERRORS_IF_LESS_THAN Maximum number of errors allowed 0

IDE Integration

Use rubocop in your favorite IDE to catch errors before Mega-Linter !

IDE Extension Name Install
Atom linter-rubocop Visit Web Site
Brackets brackets-rubocop Visit Web Site
Emacs rubocop-emacs Visit Web Site
Emacs flycheck Visit Web Site
IDEA RubyMine Visit Web Site
Sublime Text sublime_rubocop Visit Web Site
vim vim-rubocop Visit Web Site
vim ale Visit Web Site
Visual Studio Code VsCode Ruby Extension Install in VsCode

Mega-Linter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default Mega-Linter Flavor 94 Docker Image Size (tag) Docker Pulls
ruby Optimized for RUBY based projects 41 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

  • File extensions: .rb

How the linting is performed

  • rubocop is called one time by identified file

Example calls

rubocop --force-exclusion myfile.rb
rubocop --force-exclusion -c .ruby-lint.yml myfile.rb
rubocop --force-exclusion --safe-auto-correct -c .ruby-lint.yml myfile.rb

Help content

Usage: rubocop [options] [file1, file2, ...]
    -L, --list-target-files          List all files RuboCop will inspect.
        --except [COP1,COP2,...]     Disable the given cop(s).
        --only [COP1,COP2,...]       Run only the given cop(s).
        --only-guide-cops            Run only cops for rules that link to a
                                     style guide.
    -c, --config FILE                Specify configuration file.
        --force-exclusion            Force excluding files specified in the
                                     configuration `Exclude` even if they are
                                     explicitly passed as arguments.
        --ignore-parent-exclusion    Prevent from inheriting AllCops/Exclude from
                                     parent folders.
        --force-default-config       Use default configuration even if configuration
                                     files are present in the directory tree.
        --auto-gen-config            Generate a configuration file acting as a
                                     TODO list.
        --exclude-limit COUNT        Used together with --auto-gen-config to
                                     set the limit for how many Exclude
                                     properties to generate. Default is 15.
        --disable-uncorrectable      Used with --auto-correct to annotate any
                                     offenses that do not support autocorrect
                                     with `rubocop:todo` comments.
        --no-offense-counts          Do not include offense counts in configuration
                                     file generated by --auto-gen-config.
        --auto-gen-only-exclude      Generate only Exclude parameters and not Max
                                     when running --auto-gen-config, except if the
                                     number of files with offenses is bigger than
        --no-auto-gen-timestamp      Do not include the date and time when
                                     the --auto-gen-config was run in the file it
        --init                       Generate a .rubocop.yml file in the current directory.
    -f, --format FORMATTER           Choose an output formatter. This option
                                     can be specified multiple times to enable
                                     multiple formatters at the same time.
                                     [p]rogress is used by default
                                       custom formatter class name
    -o, --out FILE                   Write output to a file instead of STDOUT.
                                     This option applies to the previously
                                     specified --format, or the default format
                                     if no format is specified.
    -r, --require FILE               Require Ruby file.
        --fail-level SEVERITY        Minimum severity (A/R/C/W/E/F) for exit
                                     with error code.
                                     Only output offense messages at
                                     the specified --fail-level or above
        --show-cops [COP1,COP2,...]  Shows the given cops, or all cops by
                                     default, and their configurations for the
                                     current directory.
    -F, --fail-fast                  Inspect files in order of modification
                                     time and stop after the first file
                                     containing offenses.
    -C, --cache FLAG                 Use result caching (FLAG=true) or don't
                                     (FLAG=false), default determined by
                                     configuration parameter AllCops: UseCache.
    -d, --debug                      Display debug info.
    -D, --[no-]display-cop-names     Display cop names in offense messages.
                                     Default is true.
    -E, --extra-details              Display extra details in offense messages.
    -S, --display-style-guide        Display style guide URLs in offense messages.
    -a, --auto-correct               Auto-correct offenses.
        --disable-pending-cops       Run without pending cops.
        --enable-pending-cops        Run with pending cops.
        --ignore-disable-comments    Run cops even when they are disabled locally
                                     with a comment.
        --safe                       Run only safe cops.
        --[no-]color                 Force color output on or off.
    -v, --version                    Display version.
    -V, --verbose-version            Display verbose version.
    -P, --parallel                   Use available CPUs to execute inspection in
    -l, --lint                       Run only lint cops.
    -x, --fix-layout                 Run only layout cops, with auto-correct on.
        --safe-auto-correct          Run auto-correct only when it's safe.
    -s, --stdin FILE                 Pipe source from STDIN, using FILE in offense
                                     reports. This is useful for editor integration.

Installation on mega-linter Docker image

Example success log

Results of rubocop linter (version 0.82.0)
See documentation on

[SUCCESS] .automation/test/ruby/ruby_good_1.rb
    Inspecting 1 file

    1 file inspected, no offenses detected

Example error log

Results of rubocop linter (version 0.82.0)
See documentation on

[ERROR] .automation/test/ruby/ruby_bad_1.rb
    Inspecting 1 file


    mp/lint/.automation/test/ruby/ruby_bad_1.rb:1:1: C: Style/FrozenStringLiteralComment: Missing frozen string literal comment.
    mp/lint/.automation/test/ruby/ruby_bad_1.rb:11:11: C: Style/StringLiterals: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.'/tmp/urls.txt', " w" ) do | file|
    mp/lint/.automation/test/ruby/ruby_bad_1.rb:11:32: C: Layout/SpaceInsideParens: Space inside parentheses detected.'/tmp/urls.txt', " w" ) do | file|
    mp/lint/.automation/test/ruby/ruby_bad_1.rb:11:39: C: Layout/SpaceAroundBlockParameters: Space before first block parameter detected.'/tmp/urls.txt', " w" ) do | file|
    mp/lint/.automation/test/ruby/ruby_bad_1.rb:12:24: C: Layout/SpaceAroundBlockParameters: Space after last block parameter detected. do |h |
    mp/lint/.automation/test/ruby/ruby_bad_1.rb:13:13: C: Layout/SpaceInsideArrayLiteralBrackets: Do not use space inside array brackets.

    1 file inspected, 6 offenses detected