Rule: cyclomatic-complexity

Enforces a threshold of cyclomatic complexity.

Cyclomatic complexity is assessed for each function of any type. A starting value of 0 is assigned and this value is then incremented for every statement which can branch the control flow within the function. The following statements and expressions contribute to cyclomatic complexity:

  • catch
  • if and ? :
  • || and && due to short-circuit evaluation
  • for, for in and for of loops
  • while and do while loops
  • case clauses that contain statements

Cyclomatic complexity is a code metric which indicates the level of complexity in a function. High cyclomatic complexity indicates confusing code which may be prone to errors or difficult to modify.

It’s better to have smaller, single-purpose functions with self-documenting names.


An optional upper limit for cyclomatic complexity can be specified. If no limit option is provided a default value of 20 will be used.

Config examples
"cyclomatic-complexity": true
"cyclomatic-complexity": [true, 20]
  "type": "number",
  "minimum": 2