1'use strict' 2module.exports = isOnlyDev 3 4const moduleName = require('../utils/module-name.js') 5const isDevDep = require('./is-dev-dep.js') 6const isProdDep = require('./is-prod-dep.js') 7 8// Returns true if the module `node` is only required direcctly as a dev 9// dependency of the top level or transitively _from_ top level dev 10// dependencies. 11// Dual mode modules (that are both dev AND prod) should return false. 12function isOnlyDev (node, seen) { 13 if (!seen) seen = new Set() 14 return node.requiredBy.length && node.requiredBy.every(andIsOnlyDev(moduleName(node), seen)) 15} 16 17// There is a known limitation with this implementation: If a dependency is 18// ONLY required by cycles that are detached from the top level then it will 19// ultimately return true. 20// 21// This is ok though: We don't allow shrinkwraps with extraneous deps and 22// these situation is caught by the extraneous checker before we get here. 23function andIsOnlyDev (name, seen) { 24 return function (req) { 25 const isDev = isDevDep(req, name) 26 const isProd = isProdDep(req, name) 27 if (req.isTop) { 28 return isDev && !isProd 29 } else { 30 if (seen.has(req)) return true 31 seen.add(req) 32 const result = isOnlyDev(req, seen) 33 seen.delete(req) 34 return result 35 } 36 } 37} 38