node/deps/npm/test/tap/ls-no-results.js

var test = require('tap').test
var spawn = require('child_process').spawn
var node = process.execPath
var npm = require.resolve('../../')
var args = [ npm, 'ls', 'ceci n’est pas une package' ]
test('ls exits non-zero when nothing found', function (t) {
  var child = spawn(node, args)
  child.on('exit', function (code) {
    t.notEqual(code, 0)
    t.end()
  })
})