ddd-ts-kit/clean-stepdown

Architecture id: clean/stepdown. Default severity: error in recommended, error in strict.

Applies to: every linted file.

Why

A file reads like a newspaper: the intention at the top, the details below. A reader who opens a class meets what it does before how, and never has to scroll up to find the helper a function just called.

Reported

• a private, #private or protected method declared before a public method
• a public static method declared after a public instance method (static factories come first)
• a private method declared above its first caller
• a non-exported top-level function, or constant holding a function, declared above its first caller

Incorrect:

function price(line: Line): number {
  return line.unit * line.quantity;
}

export function total(lines: Line[]): number {
  return lines.map(price).reduce(add, 0);
}

Correct:

export function total(lines: Line[]): number {
  return lines.map(price).reduce(add, 0);
}

function price(line: Line): number {
  return line.unit * line.quantity;
}

Details

Callers are found with the scope manager for functions, and through this.x, this.#x and ClassName.x for members. Recursion and mutual recursion have no right order and are not reported. A constant holding a function is left alone when it is used while the module loads, since moving it below that use would break at run time.

Options

None.

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

Limits

• A member called only through another receiver than this or the class name (other.#helper()) has no known caller and is not reported.
• Constructors, properties that do not hold a function, accessors without body and overload signatures are neutral.
• An exported function is never asked to move: the order between exported functions is the author's.

With the CLI checker

ddd-ts-kit check approximates this rule on the text of the file and stays the fast edit-time guard. This rule is the authority.