eslint-plugin-promise/rules/lib/is-inside-callback.js

Enforce best practices for JavaScript promises

'use strict'

const isInsidePromise = require('./is-inside-promise')

/**
 * @param {import('eslint').Rule.Node} node
 * @param {boolean} [exemptDeclarations]
 */
function isInsideCallback(node, exemptDeclarations) {
  const isFunction =
    node.type === 'FunctionExpression' ||
    node.type === 'ArrowFunctionExpression' ||
    (!exemptDeclarations && node.type === 'FunctionDeclaration') // this may be controversial

  // it's totally fine to use promises inside promises
  if (isInsidePromise(node)) return

  const name = node.params && node.params[0] && node.params[0].name
  const firstArgIsError = name === 'err' || name === 'error'
  const isInACallback = isFunction && firstArgIsError
  return isInACallback
}

module.exports = isInsideCallback