Failing test for database reopening

This ensures that random-access-idb files are consistent across IndexedDB
sessions, in particular with respect to the .length property

Author: nothingmuch

test/reopen.js

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+var test = require('tape')
+var rai = require('../')('testing-' + Math.random(), { size: 256 })
+var ram = require('random-access-memory')
+var randombytes = require('randombytes')
+var bequal = require('buffer-equals')
+var balloc = require('buffer-alloc')
+
+test.only('random', function (t) {
+  var nwrites = 100, nreads = 100
+  t.plan(2 + nwrites*2 + nreads)
+
+  // this test differs from random.js in that it interleaves writes/reads, and randomly reopens the idb based storage some of the time
+  var store = rai('cool.txt')
+  function istore() {if (Math.random() > 0.75) store = rai('cool.txt'); return store }
+
+  var mstore = ram('cool.txt')
+
+  ;(function () {
+    var zeros = balloc(500+100)
+    var pending = 2
+    istore().write(0, zeros, function (err) {
+      t.ifError(err)
+      if (--pending === 0) write(0)
+    })
+    mstore.write(0, zeros, function (err) {
+      t.ifError(err)
+      if (--pending === 0) write(0)
+    })
+  })()
+
+  function write (i) {
+    if (i === nwrites) return read(0)
+    var offset = Math.floor(Math.random() * 500)
+    var buf = randombytes(Math.floor(Math.random() * 100))
+    var pending = 2
+    istore().write(offset, buf, function (err) {
+      t.ifError(err)
+      if (--pending === 0) read(i+1)
+    })
+    mstore.write(offset, buf, function (err) {
+      t.ifError(err)
+      if (--pending === 0) read(i+1)
+    })
+  }
+
+  function read (i) {
+    if (i === nreads) return 
+    var offset = Math.floor(Math.random() * 650)
+    var len = Math.floor(Math.random()*100)
+    var pending = 2, idata = {}, mdata = {}
+    var store = istore()
+    store.read(offset, len, function (err, buf) {
+      idata = { err: err, buf: buf, length: store.length }
+      if (--pending === 0) check()
+    })
+    mstore.read(offset, len, function (err, buf) {
+      mdata = { err: err, buf: buf, length: mstore.length }
+      if (--pending === 0) check()
+    })
+    function check () {
+      t.deepEqual(idata, mdata)
+      write(i+1)
+    }
+  }
+})