class RuboCop::Cop::Style::MethodCallWithArgsParentheses

Enforces the presence (default) or absence of parentheses in method calls containing arguments.

In the default style (require_parentheses), macro methods are allowed. Additional methods can be added to the ‘AllowedMethods` or `AllowedPatterns` list. These options are valid only in the default style. Macros can be included by either setting `IgnoreMacros` to false or adding specific macros to the `IncludedMacros` list.

Precedence of options is as follows:

  1. ‘AllowedMethods`

  2. ‘AllowedPatterns`

  3. ‘IncludedMacros`

If a method is listed in both ‘IncludedMacros` and `AllowedMethods`, then the latter takes precedence (that is, the method is allowed).

In the alternative style (omit_parentheses), there are three additional options.

  1. ‘AllowParenthesesInChaining` is `false` by default. Setting it to `true` allows the presence of parentheses in the last call during method chaining.

  2. ‘AllowParenthesesInMultilineCall` is `false` by default. Setting it

    to `true` allows the presence of parentheses in multi-line method
    calls.
  3. ‘AllowParenthesesInCamelCaseMethod` is `false` by default. This

    allows the presence of parentheses when calling a method whose name
    begins with a capital letter and which has no arguments. Setting it
    to `true` allows the presence of parentheses in such a method call
    even with arguments.

NOTE: The style of ‘omit_parentheses` allows parentheses in cases where omitting them results in ambiguous or syntactically incorrect code.

Non-exhaustive list of examples:

@example EnforcedStyle: require_parentheses (default)

# bad
array.delete e

# good
array.delete(e)

# good
# Operators don't need parens
foo == bar

# good
# Setter methods don't need parens
foo.bar = baz

# okay with `puts` listed in `AllowedMethods`
puts 'test'

# okay with `^assert` listed in `AllowedPatterns`
assert_equal 'test', x

@example EnforcedStyle: omit_parentheses

# bad
array.delete(e)

# good
array.delete e

# bad
action.enforce(strict: true)

# good
action.enforce strict: true

# good
# Parentheses are allowed for code that can be ambiguous without
# them.
action.enforce(condition) || other_condition

# good
# Parentheses are allowed for calls that won't produce valid Ruby
# without them.
yield path, File.basename(path)

# good
# Omitting the parentheses in Ruby 3.1 hash omission syntax can lead
# to ambiguous code. We allow them in conditionals and non-last
# expressions. See https://bugs.ruby-lang.org/issues/18396
if meets(criteria:, action:)
  safe_action(action) || dangerous_action(action)
end

@example IgnoreMacros: true (default)

# good
class Foo
  bar :baz
end

@example IgnoreMacros: false

# bad
class Foo
  bar :baz
end

@example AllowedMethods: [“puts”, “print”]

# good
puts "Hello world"
print "Hello world"
# still enforces parentheses on other methods
array.delete(e)

@example AllowedPatterns: [“^assert”]

# good
assert_equal 'test', x
assert_match(/foo/, bar)
# still enforces parentheses on other methods
array.delete(e)

@example AllowParenthesesInMultilineCall: false (default)

# bad
foo.enforce(
  strict: true
)

# good
foo.enforce \
  strict: true

@example AllowParenthesesInMultilineCall: true

# good
foo.enforce(
  strict: true
)

# good
foo.enforce \
  strict: true

@example AllowParenthesesInChaining: false (default)

# bad
foo().bar(1)

# good
foo().bar 1

@example AllowParenthesesInChaining: true

# good
foo().bar(1)

# good
foo().bar 1

@example AllowParenthesesInCamelCaseMethod: false (default)

# bad
Array(1)

# good
Array 1

@example AllowParenthesesInCamelCaseMethod: true

# good
Array(1)

# good
Array 1

@example AllowParenthesesInStringInterpolation: false (default)

# bad
"#{t('this.is.bad')}"

# good
"#{t 'this.is.better'}"

@example AllowParenthesesInStringInterpolation: true

# good
"#{t('this.is.good')}"

# good
"#{t 'this.is.also.good'}"