Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

In Ruby 3.1, anonymous block forwarding has been added.

This cop identifies places where do_something(&block) can be replaced by do_something(&).

It also supports the opposite style by alternative explicit option. You can specify the block variable name for autocorrection with BlockForwardingName. The default variable name is block. If the name is already in use, it will not be autocorrected.

Example: EnforcedStyle: anonymous (default)

# bad
def foo(&block)
  bar(&block)
end
 
# good
def foo(&)
  bar(&)
end

Example: EnforcedStyle: explicit

# bad
def foo(&)
  bar(&)
end
 
# good
def foo(&block)
  bar(&block)
end

In Ruby 3.1, anonymous block forwarding has been added.

This cop identifies places where do_something(&block) can be replaced by do_something(&).

It also supports the opposite style by alternative explicit option. You can specify the block variable name for autocorrection with BlockForwardingName. The default variable name is block. If the name is already in use, it will not be autocorrected.

Example: EnforcedStyle: anonymous (default)

# bad
def foo(&block)
  bar(&block)
end
 
# good
def foo(&)
  bar(&)
end

Example: EnforcedStyle: explicit

# bad
def foo(&)
  bar(&)
end
 
# good
def foo(&block)
  bar(&block)
end