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Mega-Linter is an 100% Open-Source tool for CI/CD workflows that analyzes consistency and quality of 48 languages, 22 formats, 19 tooling formats , abusive copy-pastes and spelling mistakes in your repository sources, generates various reports, and can even apply formatting and auto-fixes, to ensure all your projects sources are clean, whatever IDE/toolbox are used by their developers.

Ready to use out of the box as a GitHub Action or any CI system, highly configurable and free for all uses

Why Mega-Linter

Projects need to contain clean code, in order to avoid technical debt, that makes evolutive maintenance harder and time consuming.

By using code formatters and code linters, you ensure that your code base is easier to read and respects best practices, from the kick-off to each step of the project lifecycle

Not all developers have the good habit to use linters in their IDEs, making code reviews harder and longer to process

By using Mega-Linter, you'll enjoy the following benefits for you and your team:

• At each pull request it will automatically analyze all updated code in all languages
• Reading error logs, developers learn best practices of the language they are using
• Mega-Linter documentation provides the list of IDE plugins integrating each linter, so developers know which linter and plugins to install
• Mega-Linter is ready out of the box after a quick setup
• Formatting and fixes can be automatically applied on the git branch or provided in reports
• This tool is 100% open-source and free for all uses (personal, professional, public and private repositories)
• Mega-Linter can run on any CI tool and be run locally: no need to authorize an external application, and your code base never leaves your tooling ecosystem

Supported Linters

All linters are integrated in the Mega-Linter docker image, which is frequently upgraded with their latest versions

Languages

	Language	Linter	Configuration key	Format/Fix
	BASH	bash-exec	BASH_EXEC
		shellcheck	BASH_SHELLCHECK
		shfmt	BASH_SHFMT
	C	cpplint	C_CPPLINT
	CLOJURE	clj-kondo	CLOJURE_CLJ_KONDO
	COFFEE	coffeelint	COFFEE_COFFEELINT
	C++ (CPP)	cpplint	CPP_CPPLINT
	C# (CSHARP)	dotnet-format	CSHARP_DOTNET_FORMAT
	DART	dartanalyzer	DART_DARTANALYZER
	GO	golangci-lint	GO_GOLANGCI_LINT
		revive	GO_REVIVE
	GROOVY	npm-groovy-lint	GROOVY_NPM_GROOVY_LINT
	JAVA	checkstyle	JAVA_CHECKSTYLE
	JAVASCRIPT	eslint	JAVASCRIPT_ES
		standard	JAVASCRIPT_STANDARD
		prettier	JAVASCRIPT_PRETTIER
	JSX	eslint	JSX_ESLINT
	KOTLIN	ktlint	KOTLIN_KTLINT
	LUA	luacheck	LUA_LUACHECK
	PERL	perlcritic	PERL_PERLCRITIC
	PHP	php	PHP_BUILTIN
		phpcs	PHP_PHPCS
		phpstan	PHP_PHPSTAN
		psalm	PHP_PSALM
	POWERSHELL	powershell	POWERSHELL_POWERSHELL
	PYTHON	pylint	PYTHON_PYLINT
		black	PYTHON_BLACK
		flake8	PYTHON_FLAKE8
		isort	PYTHON_ISORT
		bandit	PYTHON_BANDIT
		mypy	PYTHON_MYPY
	R	lintr	R_LINTR
	RAKU	raku	RAKU_RAKU
	RUBY	rubocop	RUBY_RUBOCOP
	RUST	clippy	RUST_CLIPPY
	SALESFORCE	sfdx-scanner-apex	SALESFORCE_SFDX_SCANNER_APEX
		sfdx-scanner-aura	SALESFORCE_SFDX_SCANNER_AURA
		sfdx-scanner-lwc	SALESFORCE_SFDX_SCANNER_LWC
	SCALA	scalafix	SCALA_SCALAFIX
	SQL	sql-lint	SQL_SQL_LINT
		sqlfluff	SQL_SQLFLUFF
		tsqllint	SQL_TSQLLINT
	SWIFT	swiftlint	SWIFT_SWIFTLINT
	TSX	eslint	TSX_ESLINT
	TYPESCRIPT	eslint	TYPESCRIPT_ES
		standard	TYPESCRIPT_STANDARD
		prettier	TYPESCRIPT_PRETTIER
	Visual Basic .NET (VBDOTNET)	dotnet-format	VBDOTNET_DOTNET_FORMAT

Formats

	Format	Linter	Configuration key	Format/Fix
	CSS	stylelint	CSS_STYLELINT
		scss-lint	CSS_SCSS_LINT
	ENV	dotenv-linter	ENV_DOTENV_LINTER
	GRAPHQL	graphql-schema-linter	GRAPHQL_GRAPHQL_SCHEMA_LINTER
	HTML	htmlhint	HTML_HTMLHINT
	JSON	jsonlint	JSON_JSONLINT
		eslint-plugin-jsonc	JSON_ESLINT_PLUGIN_JSONC
		v8r	JSON_V8R
		prettier	JSON_PRETTIER
	LATEX	chktex	LATEX_CHKTEX
	MARKDOWN	markdownlint	MARKDOWN_MARKDOWNLINT
		remark-lint	MARKDOWN_REMARK_LINT
		markdown-link-check	MARKDOWN_MARKDOWN_LINK_CHECK
		markdown-table-formatter	MARKDOWN_MARKDOWN_TABLE_FORMATTER
	PROTOBUF	protolint	PROTOBUF_PROTOLINT
	RST	rst-lint	RST_RST_LINT
		rstcheck	RST_RSTCHECK
		rstfmt	RST_RSTFMT
	XML	xmllint	XML_XMLLINT
	YAML	prettier	YAML_PRETTIER
		yamllint	YAML_YAMLLINT
		v8r	YAML_V8R

Tooling formats

	Tooling format	Linter	Configuration key	Format/Fix
	ACTION	actionlint	ACTION_ACTIONLINT
	ANSIBLE	ansible-lint	ANSIBLE_ANSIBLE_LINT
	ARM	arm-ttk	ARM_ARM_TTK
	CLOUDFORMATION	cfn-lint	CLOUDFORMATION_CFN_LINT
	DOCKERFILE	dockerfilelint	DOCKERFILE_DOCKERFILELINT
		hadolint	DOCKERFILE_HADOLINT
	EDITORCONFIG	editorconfig-checker	EDITORCONFIG_EDITORCONFIG_CHECKER
	GHERKIN	gherkin-lint	GHERKIN_GHERKIN_LINT
	KUBERNETES	kubeval	KUBERNETES_KUBEVAL
	OPENAPI	spectral	OPENAPI_SPECTRAL
	PUPPET	puppet-lint	PUPPET_PUPPET_LINT
	SNAKEMAKE	snakemake	SNAKEMAKE_LINT
		snakefmt	SNAKEMAKE_SNAKEFMT
	TEKTON	tekton-lint	TEKTON_TEKTON_LINT
	TERRAFORM	tflint	TERRAFORM_TFLINT
		terrascan	TERRAFORM_TERRASCAN
		terragrunt	TERRAFORM_TERRAGRUNT
		terraform-fmt	TERRAFORM_TERRAFORM_FMT
		checkov	TERRAFORM_CHECKOV

Other

	Code quality checker	Linter	Configuration key	Format/Fix
	COPYPASTE	jscpd	COPYPASTE_JSCPD
	CREDENTIALS	secretlint	CREDENTIALS_SECRETLINT
	GIT	git_diff	GIT_GIT_DIFF
	SPELL	misspell	SPELL_MISSPELL
		cspell	SPELL_CSPELL

V4 versus V5

• Tool to upgrade user repos configuration files using npx mega-linter-runner --upgrade (will upgrade references to nvuillam/mega-linter into megalinter/megalinter)

• Migration from github individual repo nvuillam/mega-linter to github organization repo megalinter/megalinter

• Migration from docker hub space nvuillam to space megalinter
  • Docker images are now megalinter/megalinter or megalinter/megalinter-FLAVOR

• Documentation is now hosted at https://megalinter.github.io/

• Version management: Now mega-linter docker images, github action and mega-linter-runner versions are aligned
  • latest for latest official release
  • beta for current content of main branch
  • alpha for current content of alpha branch
  • docker image, github action and mega-linter-runner can still be called with exact version number

• Being more inclusive: rename master branch into main

• IGNORE_GITIGNORED_FILES parameter default to true