ddd-ts-kit/clean-function-ceiling

Architecture id: clean/function-size. Default severity: error in recommended, error in strict.

Applies to: every linted file, tests and module files included.

Why

clean/function-size asks for short functions with a limit a project may tune, and leaves describe callbacks and module files alone. This rule is the part that is not negotiable: past 100 lines of code a function is a file in disguise, whatever it is, and a test suite of that length tests more than one thing. ESLint gives one severity to a rule name, so the ceiling is a rule of its own: an error while clean-function-size stays a warn.

Reported

• a function, a method or an arrow function whose body holds more than 100 lines of code, the callbacks of describe, suite and context and the functions of <context>.module.ts included

Incorrect:

describe('an invoice', () => {
  // 140 lines of tests about issuing, paying and voiding
});

Correct:

describe('an invoice being issued', () => {
  // the tests about issuing
});

describe('an invoice being paid', () => {
  // the tests about paying
});

Details

Lines of code are counted as clean-function-size counts them: the lines of the body that carry at least one token; blank lines and comment lines are not counted. A nested function counts in the length of the function around it.

The same number caps the configurable limit: limits.maxFunctionLines of ddd-ts-kit.config.json and the option maxLines of clean-function-size are read as 100 when they are higher.

Options

None.

rules."clean/function-size" in ddd-ts-kit.config.json set to off silences the rule, and // ddd-ts-kit-disable-next-line clean/function-size -- <reason> silences one line, exactly as for ddd-ts-kit check.

Limits

• The rule cannot be lowered to a warning from ddd-ts-kit.config.json: only off reaches it, with clean/function-size as a whole.

With the CLI checker

ddd-ts-kit check reports the ceiling under clean/function-size with the severity error, on the text of the file: methods, function declarations at any depth, function expressions and arrow functions, a class property arrow and a callback of describe or it included. It does not read the methods of an object literal, and counts a template literal written on several lines as one line. This rule is the authority.