text: var test = require('tape')
  var crypto = require('../')
  var Buffer = require('safe-buffer').Buffer
  
  test('get error message', function (t) {
    try {
      var b = crypto.randomFillSync(Buffer.alloc(10))
      t.ok(Buffer.isBuffer(b))
      t.end()
    } catch (err) {
      t.ok(/not supported/.test(err.message), '"not supported"  is in error message')
      t.end()
    }
  })
  
  test('randomfill', function (t) {
    t.plan(5)
    t.equal(crypto.randomFillSync(Buffer.alloc(10)).length, 10)
    t.ok(Buffer.isBuffer(crypto.randomFillSync(Buffer.alloc(10))))
    crypto.randomFill(Buffer.alloc(10), function (ex, bytes) {
      t.error(ex)
      t.equal(bytes.length, 10)
      t.ok(Buffer.isBuffer(bytes))
      t.end()
    })
  })
  
  test('seems random', function (t) {
    var L = 1000
    var b = crypto.randomFillSync(Buffer.alloc(L))
  
    var mean = [].reduce.call(b, function (a, b) {
      return a + b
    }, 0) / L
  
    // test that the random numbers are plausably random.
    // Math.random() will pass this, but this will catch
    // terrible mistakes such as this blunder:
    // https://github.com/dominictarr/crypto-browserify/commit/3267955e1df7edd1680e52aeede9a89506ed2464#commitcomment-7916835
  
    // this doesn't check that the bytes are in a random *order*
    // but it's better than nothing.
  
    var expected = 256 / 2
    var smean = Math.sqrt(mean)
  
    // console.log doesn't work right on testling, *grumble grumble*
    console.log(JSON.stringify([expected - smean, mean, expected + smean]))
    t.ok(mean < expected + smean)
    t.ok(mean > expected - smean)
  
    t.end()
  })
  