no-throw-statement.md

Disallow throwing exceptions (no-throw-statement)

This rule disallows the throw keyword.

Rule Details

Exceptions are not part of functional programming. As an alternative a function should return an error or in the case of an async function, a rejected promise.

Examples of incorrect code for this rule:

/* eslint functional/no-throw-statement: "error" */

throw new Error("Something went wrong.");

Examples of correct code for this rule:

/* eslint functional/no-throw-statement: "error" */

function divide(x, y) {
  return y === 0 ? new Error("Cannot divide by zero.") : x / y;
}

/* eslint functional/no-throw-statement: "error" */

async function divide(x, y) {
  const [xv, yv] = await Promise.all([x, y]);

  return yv === 0
    ? Promise.reject(new Error("Cannot divide by zero."))
    : xv / yv;
}

Options

The rule does not accept any options.