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

Rationale

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.

Config

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]

Schema

{
  "type": "number",
  "minimum": 2
}