Style-Lambda.md

Pattern: Inconsistent lambda literal syntax

Issue: -

Description

This rule (by default) checks for uses of the lambda literal syntax for single line lambdas, and the method call syntax for multi-line lambdas. It is configurable to enforce one of the styles for both single line and multi-line lambdas as well.

Examples

# EnforcedStyle: line_count_dependent (default)

# bad
f = lambda { |x| x }
f = ->(x) do
      x
    end

# good
f = ->(x) { x }
f = lambda do |x|
      x
    end

# EnforcedStyle: lambda

# bad
f = ->(x) { x }
f = ->(x) do
      x
    end

# good
f = lambda { |x| x }
f = lambda do |x|
      x
    end

# EnforcedStyle: literal

# bad
f = lambda { |x| x }
f = lambda do |x|
      x
    end

# good
f = ->(x) { x }
f = ->(x) do
      x
    end

Default configuration

Attribute	Value
EnforcedStyle	line_count_dependent
SupportedStyles	line_count_dependent, lambda, literal

Further Reading

• RuboCop - Style/Lambda
• https://github.com/bbatsov/ruby-style-guide#lambda-multi-line