My default swiftlint for professional use

.swiftlint.yml

excluded:
  - ${PWD}/Carthage
  - ${PWD}/Pods
  - ${PWD}/DerivedData
  - Package.swift

included:
  - ${PWD}

force_cast: warning

identifier_name:
  excluded:
    - i
    - x
    - y
    - z
    - r
    - db
    - id
    - vc

line_length:
  ignores_urls: true
  ignores_function_declarations: true
  ignores_comments: true
  warning: 150

function_body_length:
  warning: 70

attributes:
  always_on_same_line:
    - "@objc"

nesting:
  type_level:
    warning: 3
    error: 6
  function_level:
    warning: 5
    error: 10

cyclomatic_complexity:
  ignores_case_statements: true

file_length:
  warning: 500
  error: 750

opt_in_rules:
  - attributes # for @objc on same lone
  - array_init # Prefer using Array(seq) over seq.map { $0 } to convert a sequence into an Array
  - closure_spacing # Closure expressions should have a single space inside each brace
  - collection_alignment # All elements in a collection literal should be vertically aligned
  - comma_inheritance # Use commas to separate types in inheritance lists
  - contains_over_first_not_nil # Prefer contains over first(where:) != nil and firstIndex(where:) != nil
  - contains_over_filter_count # Prefer contains over comparing filter(where:).count to 0
  - contains_over_filter_is_empty # Prefer contains over using filter(where:).isEmpty
  - contains_over_range_nil_comparison # Prefer contains over range(of:) != nil and range(of:) == nil
  - convenience_type # Types used for hosting only static members should be implemented as a caseless enum to avoid instantiation
  - discouraged_assert # Prefer assertionFailure() and/or preconditionFailure() over assert(false)
  - empty_count # Prefer checking isEmpty over comparing count to zero
  - empty_collection_literal # Prefer checking isEmpty over comparing collection to an empty array or dictionary literal
  - empty_string # Prefer checking isEmpty over comparing string to an empty string literal
  - explicit_init # Explicitly calling .init() should be avoided
  - first_where # Prefer using .first(where:) over .filter { }.first in collections for performance
  - flatmap_over_map_reduce # Prefer flatMap over map followed by reduce([], +)
  - force_unwrapping # Force unwrapping should be avoided
  - force_try # Force tries should be avoided
  - indentation_width
  - identical_operands # Don't compare the same thing, lol
  - joined_default_parameter # perfer joined() over joined(seperator: "")
  - last_where # Prefer using .last(where:) over .filter { }.last in collections
  - local_doc_comment # Prefer regular comments over doc comments in local scopes
  - lower_acl_than_parent # Ensure declarations have a lower access control level than their enclosing parent
  - modifier_order # Modifier order should be consistent
  - operator_usage_whitespace # Operators should be surrounded by a single whitespace when they are being used
  - optional_enum_case_matching # Matching an enum case against an optional enum without ‘?’ is supported on Swift 5.1 and above
  - overridden_super_call # Some overridden methods should always call super.
  - pattern_matching_keywords # Combine multiple pattern matching bindings by moving keywords out of tuples
  - prohibited_interface_builder # Disallows the usage of @IBOutlet and @IBAction
  - prohibited_super_call # Some methods should not call super.
  - reduce_into # Prefer reduce(into:_:) over reduce(_:_:) for copy-on-write types
  - redundant_type_annotation # Variables should not have redundant type annotation
  - shorthand_optional_binding # Use shorthand syntax for optional binding
  - sorted_first_last # Prefer using min() or max() over sorted().first or sorted().last
  - toggle_bool # Prefer toggle() instead of boolean = !boolean
  - unused_declaration # Declarations should be referenced at least once within all files linted
  - vertical_parameter_alignment_on_call # Function parameters should be aligned vertically if they’re in multiple lines in a method call
  - yoda_condition # The constant literal should be placed on the right-hand side of the comparison operator

indentation_width:
  indentation_width: 2

disabled_rules:
  - trailing_comma

vertical_whitespace:
  max_empty_lines: 2