This is a prerelease version. It won't be published to Homebrew or CocoaPods. But there are many other ways to install:

• Downloading the attached SwiftLint.pkg installer and launching it
• Downloading the attached portable_swiftlint.zip archive, extracting it and moving the binary from portable_swiftlint/swiftlint to /usr/local/bin or elsewhere in your PATH
• Using Mint: mint install realm/SwiftLint@0.50.0-rc.4
• Cloning and building from source: git clone https://github.com/realm/SwiftLint.git && cd SwiftLint && git checkout 0.50.0-rc.4 && make install
• Docker: docker run -it -v `pwd`:`pwd` -w `pwd` ghcr.io/realm/swiftlint:0.50.0-rc.4
• Bazel: See instructions at the bottom

Changes from 0.49.1: https://github.com/realm/SwiftLint/compare/0.49.1...0.50.0-rc.4 Changes from 0.50.0-rc.3: https://github.com/realm/SwiftLint/compare/0.50.0-rc.3...0.50.0-rc.4

Breaking

• SwiftLint now requires Swift 5.7 or higher to build.
  JP Simard

• Exclude weak_delegate rule from autocorrection due to behavioral changes leading to potential undefined behavior or bugs.
  SimplyDanny #3577

• The anyobject_protocol rule is now deprecated and will be completely removed in a future release because it is now handled by the Swift compiler.
  JP Simard

Experimental

• None.

Enhancements

• Adds NSError to the list of types in discouraged_direct_init.
  jszumski #4508

• Fix SwiftLint support on Xcode Cloud.
  JagCesar westerlund #4484

• Add no_magic_numbers rule to avoid "Magic Numbers".
  Henrik Storch #4031

• SwiftSyntax libraries have been updated from the previous 5.6 release and now use the new parser written in Swift. Swift 5.7+ features should now be parsed more accurately. We've also measured an improvement in lint times of up to 15%. This should also fix some deployment issues where the exact version of the internal SwiftSyntax parser needed to be available. If you notice any unexpected changes to lint results, please file an issue on the SwiftLint issue tracker. We can look into it and if it's a SwiftSyntax parser regression we can re-file it upstream.
  JP Simard #4031

• Add ability to filter rules for generate-docs subcommand.
  kattouf

• Add new excludes_trivial_init configuration for missing_docs rule to exclude initializers without any parameters.
  Marcelo Fabri #4107

• Add new ns_number_init_as_function_reference rule to catch NSNumber.init and NSDecimalNumber.init being used as function references since it can cause the wrong initializer to be used, causing crashes. See https://github.com/apple/swift/issues/51036 for more info.
  Marcelo Fabri

• Rewrite some rules with SwiftSyntax, fixing some false positives and catching more violations:

  • anonymous_argument_in_multiline_closure
  • array_init
  • attributes
  • block_based_kvo
  • class_delegate_protocol
  • closing_brace
  • closure_body_length
  • closure_parameter_position
  • collection_alignment
  • comment_spacing
  • computed_accessors_order
  • conditional_returns_on_newline
  • contains_over_filter_count
  • contains_over_filter_is_empty
  • contains_over_first_not_nil
  • contains_over_range_nil_comparison
  • convenience_type
  • deployment_target
  • discarded_notification_center_observer
  • discouraged_assert
  • discouraged_direct_init
  • discouraged_none_name
  • discouraged_object_literal
  • discouraged_optional_boolean
  • duplicate_enum_cases
  • duplicated_key_in_dictionary_literal
  • dynamic_inline
  • empty_collection_literal
  • empty_count
  • empty_enum_arguments
  • empty_parameters
  • empty_parentheses_with_trailing_closure
  • empty_string
  • enum_case_associated_values_count
  • explicit_enum_raw_value
  • explicit_init
  • explicit_top_level_acl
  • fallthrough
  • file_name
  • first_where
  • flatmap_over_map_reduce
  • for_where
  • force_try
  • force_unwrapping
  • function_body_length
  • function_default_parameter_at_end
  • function_parameter_count
  • generic_type_name
  • ibinspectable_in_extension
  • identical_operands
  • implicit_getter
  • implicitly_unwrapped_optional
  • inclusive_language
  • inert_defer
  • is_disjoint
  • joined_default_parameter
  • large_tuple
  • last_where
  • legacy_cggeometry_functions
  • legacy_constant
  • legacy_constructor
  • legacy_hashing
  • legacy_multiple
  • legacy_nsgeometry_functions
  • legacy_objc_type
  • legacy_random
  • lower_acl_than_parent
  • multiline_arguments_brackets
  • multiline_parameters
  • multiple_closures_with_trailing_closure
  • no_extension_access_modifier
  • no_fallthrough_only
  • no_space_in_method_call
  • notification_center_detachment
  • nslocalizedstring_require_bundle
  • nsobject_prefer_isequal
  • number_separator
  • operator_whitespace
  • optional_enum_case_matching
  • orphaned_doc_comment
  • overridden_super_call
  • override_in_extension
  • prefer_nimble
  • prefer_self_type_over_type_of_self
  • prefer_zero_over_explicit_init
  • prefixed_toplevel_constant
  • private_action
  • private_outlet
  • private_over_fileprivate
  • private_subject
  • private_unit_test
  • prohibited_interface_builder
  • prohibited_super_call
  • protocol_property_accessors_order
  • quick_discouraged_focused_test
  • quick_discouraged_pending_test
  • raw_value_for_camel_cased_codable_enum
  • reduce_boolean
  • reduce_into
  • redundant_discardable_let
  • redundant_nil_coalescing
  • redundant_objc_attribute
  • redundant_optional_initialization
  • redundant_set_access_control
  • redundant_string_enum_value
  • required_deinit
  • return_arrow_whitespace
  • self_in_property_initialization
  • shorthand_operator
  • single_test_class
  • sorted_first_last
  • static_operator
  • strict_fileprivate
  • strong_iboutlet
  • switch_case_alignment
  • switch_case_on_newline
  • test_case_accessibility
  • toggle_bool
  • trailing_comma
  • trailing_semicolon
  • type_body_length
  • type_name
  • unneeded_break_in_switch
  • unneeded_parentheses_in_closure_argument
  • unowned_variable_capture
  • untyped_error_in_catch
  • unused_capture_list
  • unused_closure_parameter
  • unused_control_flow_label
  • unused_enumerated
  • unused_optional_binding
  • unused_setter_value
  • valid_ibinspectable
  • vertical_parameter_alignment
  • weak_delegate
  • xct_specific_matcher
  • xctfail_message
    Marcelo Fabri SimplyDanny JP Simard #2915

• The "body length" family of rules have changed how they calculate body line count to be significantly more correct and intuitive. However, this is likely to require adjustments to your configuration or disable commands to account for the changes.
  JP Simard

• Add accessibility_trait_for_button rule to warn if a SwiftUI View has a tap gesture added to it without having the button or link accessibility trait.
  Ryan Cole

• Add methods from SE-0348 to UnusedDeclarationRule.
  JP Simard

• Include the configured bind_identifier in self_binding violation messages.
  JP Simard

• Add library_content_provider file type to file_types_order rule to allow LibraryContentProvider to be ordered independent from main_type.
  dahlborn

• Add test_parent_classes option to test_case_accessibility rule, which allows detection in subclasses of XCTestCase.
  Martin Redington #4200

• Add a new shorthand_optional_binding opt-in rule that triggers in Swift 5.7 when a shadowing optional binding is created in an if or guard statement.
  SimplyDanny #4202

• Use SwiftSyntax instead of SourceKit to determine if a file has parser errors before applying corrections. This speeds up corrections significantly when none of the rules use SourceKit.
  JP Simard

• Add Swift Package Build Tool Plugin with support for Swift Packages and Xcode projects.
  Johannes Ebeling #3679 #3840

• Make private_unit_test rule correctable.
  SimplyDanny

• Disregard whitespace differences in identical_operands rule. That is, the rule now also triggers if the left-hand side and the right-hand side of an operation only differ in trivia.
  SimplyDanny

• Print violations in realtime if --progress and --output are both set.
  JP Simard

• Update for_where rule, adding a new configuration allow_for_as_filter to allow using for in with a single if inside when there's a return statement inside the if's body.
  Marcelo Fabri #4040

• quick_discouraged_call, quick_discouraged_focused_test and quick_discouraged_pending_test rules now trigger on subclasses of QuickSpec. Marcelo Fabri #4420

• The type_name rule now validates protocol declarations by default. You can opt-out by using the validate_protocols key in your configuration:

  type_name:
    validate_protocols: false
  

  Marcelo Fabri #4430

• Report how much memory was used when --benchmark is specified.
  JP Simard

Bug Fixes

• Respect validates_start_with_lowercase option when linting function names.
  Chris Brakebill #2708

• Do not report variables annotated with @NSApplicationDelegateAdaptor and @WKExtensionDelegateAdaptor in weak_delegate rule.
  Till Hainbach #3598 #3611

• Fix false-positives related to the willMove lifecycle method in type_contents_order rule.
  SimplyDanny #3478

• Do no longer autocorrect usage of NSIntersectionRect in legacy_nsgeometry_functions rule.
  SimplyDanny #3703

• Fix Analyzer rules in Xcode 14.
  SimplyDanny #4208

• Add column for SourceKit usage to rules command.
  JP Simard

• Make nsobject_prefer_isequal rule work for nested @objc classes. Also consider the @objcMembers annotation.
  SimplyDanny

• Print fixed content at most once to STDOUT.
  SimplyDanny #4211

• Fix fatal error when content given via STDIN is corrected in the trailing_newline rule.
  SimplyDanny #4234

• Fix false-positives from multiline_arguments_brackets when a function call has a single line trailing closure.
  CraigSiemens #4510

Using Bazel

Put this in your WORKSPACE:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "build_bazel_rules_apple",
    sha256 = "90e3b5e8ff942be134e64a83499974203ea64797fd620eddeb71b3a8e1bff681",
    url = "https://github.com/bazelbuild/rules_apple/releases/download/1.1.2/rules_apple.1.1.2.tar.gz",
)

load(
    "@build_bazel_rules_apple//apple:repositories.bzl",
    "apple_rules_dependencies",
)

apple_rules_dependencies()

load(
    "@build_bazel_rules_swift//swift:repositories.bzl",
    "swift_rules_dependencies",
)

swift_rules_dependencies()

load(
    "@build_bazel_rules_swift//swift:extras.bzl",
    "swift_rules_extra_dependencies",
)

swift_rules_extra_dependencies()

http_archive(
    name = "SwiftLint",
    sha256 = "ef49a8c0dcb70fb5befe549b016735deef72e1ac9f68562b288f23e496c164af",
    url = "https://github.com/realm/SwiftLint/releases/download/0.50.0-rc.4/bazel.tar.gz",
)

load("@SwiftLint//bazel:repos.bzl", "swiftlint_repos")

swiftlint_repos()

load("@SwiftLint//bazel:deps.bzl", "swiftlint_deps")

swiftlint_deps()

Then you can run SwiftLint in the current directory with this command:

bazel run @SwiftLint//:swiftlint -- --help