From ed791ef0ac8bfd71d4d776a1b9ebb88fda7132f0 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:27:34 +0200
Subject: [PATCH 01/22] upgrade abstract-leveldown to 5.0.0

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index fb22981..e735e1d 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
     "tape": "^4.0.0"
   },
   "dependencies": {
-    "abstract-leveldown": "~0.12.0",
+    "abstract-leveldown": "~5.0.0",
     "idb-wrapper": "^1.5.0",
     "isbuffer": "~0.0.0",
     "ltgt": "^2.1.2",

From 558fb21908b4ada26ed5ccf3fc84b8e6b56d233b Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:28:06 +0200
Subject: [PATCH 02/22] upgrade levelup to 3.0.0

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index e735e1d..f0377ad 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   "devDependencies": {
     "airtap": "0.0.5",
     "browserify": "~16.2.2",
-    "levelup": "~0.18.2",
+    "levelup": "~3.0.0",
     "tape": "^4.0.0"
   },
   "dependencies": {

From 75480e2bc86c19be71fcc98742ac91ea0a6aaaa1 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:30:58 +0200
Subject: [PATCH 03/22] include abstract/iterator-range-test

---
 test/test.js | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/test/test.js b/test/test.js
index 28ab3dc..fba4c83 100644
--- a/test/test.js
+++ b/test/test.js
@@ -18,11 +18,7 @@ require('abstract-leveldown/abstract/batch-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/chained-batch-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/close-test').close(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/iterator-test').all(leveljs, tape, testCommon)
-
-// NOTE: exclude this because the handling of buffers is inconsistent between
-// iterator-test and ranges-test. We can't make both pass, but that's OK, as
-// ranges-test is removed in a later abstract-leveldown version anyway.
-// require('abstract-leveldown/abstract/ranges-test').all(leveljs, tape, testCommon)
+require('abstract-leveldown/abstract/iterator-range-test').all(leveljs, tape, testCommon)
 
 // non abstract-leveldown tests:
 require('./custom-tests.js').all(leveljs, tape, testCommon)

From f5171a803c0cfb374d1b8abecd7c1db9b8e154df Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:31:41 +0200
Subject: [PATCH 04/22] remove testBuffer

---
 test/test.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/test/test.js b/test/test.js
index fba4c83..77893e2 100644
--- a/test/test.js
+++ b/test/test.js
@@ -5,15 +5,13 @@ var testCommon = require('./testCommon')
 // load IndexedDBShim in the tests
 require('./idb-shim.js')()
 
-var testBuffer = Buffer.from('foo')
-
 /*** compatibility with basic LevelDOWN API ***/
 require('abstract-leveldown/abstract/leveldown-test').args(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/open-test').open(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/put-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/del-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/get-test').all(leveljs, tape, testCommon)
-require('abstract-leveldown/abstract/put-get-del-test').all(leveljs, tape, testCommon, testBuffer)
+require('abstract-leveldown/abstract/put-get-del-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/batch-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/chained-batch-test').all(leveljs, tape, testCommon)
 require('abstract-leveldown/abstract/close-test').close(leveljs, tape, testCommon)

From 698cc8bf071c0d7fdfa5fb955552ba329028ea2a Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:32:29 +0200
Subject: [PATCH 05/22] remove _isBuffer (closes #64)

---
 index.js | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/index.js b/index.js
index 4792856..545bfc7 100644
--- a/index.js
+++ b/index.js
@@ -128,10 +128,6 @@ Level.prototype._approximateSize = function (start, end, callback) {
   throw err
 }
 
-Level.prototype._isBuffer = function (obj) {
-  return Buffer.isBuffer(obj)
-}
-
 Level.destroy = function (db, callback) {
   if (typeof db === 'object') {
     var prefix = db.IDBOptions.storePrefix || 'IDBWrapper-'

From 0253f857b2390e990b608adf4a753242194dc8ff Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:33:24 +0200
Subject: [PATCH 06/22] remove _approximateSize (closes #75)

---
 index.js | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/index.js b/index.js
index 545bfc7..52c9c28 100644
--- a/index.js
+++ b/index.js
@@ -120,14 +120,6 @@ Level.prototype._close = function (callback) {
   callback()
 }
 
-Level.prototype._approximateSize = function (start, end, callback) {
-  var err = new Error('Not implemented')
-  if (callback)
-    return callback(err)
-
-  throw err
-}
-
 Level.destroy = function (db, callback) {
   if (typeof db === 'object') {
     var prefix = db.IDBOptions.storePrefix || 'IDBWrapper-'

From 9e1e61f4d530c197efa162a10879a6b177e21ecc Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:56:16 +0200
Subject: [PATCH 07/22] fix constructor

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 52c9c28..dac1da8 100644
--- a/index.js
+++ b/index.js
@@ -10,7 +10,7 @@ var toBuffer = require('typedarray-to-buffer')
 
 function Level(location) {
   if (!(this instanceof Level)) return new Level(location)
-  if (!location) throw new Error("constructor requires at least a location argument")
+  AbstractLevelDOWN.call(this, location)
   this.IDBOptions = {}
   this.location = location
 }

From fd167265dfd9dabc8f6e0eaf49a9127837e55022 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:57:57 +0200
Subject: [PATCH 08/22] fix #_iterator

---
 index.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/index.js b/index.js
index dac1da8..3947858 100644
--- a/index.js
+++ b/index.js
@@ -80,8 +80,7 @@ Level.prototype._serializeValue = function (value, options) {
   return value
 }
 
-Level.prototype.iterator = function (options) {
-  if (typeof options !== 'object') options = {}
+Level.prototype._iterator = function (options) {
   return new Iterator(this.idb, options)
 }
 

From 2da8fed4b2a89f89726a16466cb81f5d9fd3ce5b Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 13:59:02 +0200
Subject: [PATCH 09/22] rely on default options in Iterator constructor

---
 iterator.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/iterator.js b/iterator.js
index 579755f..bcd9265 100644
--- a/iterator.js
+++ b/iterator.js
@@ -24,9 +24,8 @@ function Iterator (db, options) {
   this._cache = []
   this._completed = false
 
-  // TODO: in later abstract-leveldown, these have proper defaults
-  this._keyAsBuffer = options.keyAsBuffer !== false
-  this._valueAsBuffer = options.valueAsBuffer !== false
+  this._keyAsBuffer = options.keyAsBuffer
+  this._valueAsBuffer = options.valueAsBuffer
 
   var lower = ltgt.lowerBound(options)
   var upper = ltgt.upperBound(options)

From cdd5e73f042d6970b902a0af88ec6a2aa13df2d3 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:02:06 +0200
Subject: [PATCH 10/22] add _serializeKey

---
 index.js | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/index.js b/index.js
index 3947858..7d4c15a 100644
--- a/index.js
+++ b/index.js
@@ -65,6 +65,33 @@ Level.prototype._put = function (key, value, options, callback) {
   this.idb.put(key, value, function() { callback() }, callback)
 }
 
+// Valid key types in IndexedDB Second Edition:
+//
+// - Number, except NaN. Includes Infinity and -Infinity
+// - Date, except invalid (NaN)
+// - String
+// - ArrayBuffer or a view thereof (typed arrays)
+// - Array, except cyclical and empty (e.g. Array(10)). Elements must be valid
+//   types themselves.
+Level.prototype._serializeKey = function (key) {
+  // TODO: do we still need to support ArrayBuffer?
+  if (key instanceof ArrayBuffer) return Buffer.from(key)
+
+  if (typeof key === 'string' || Buffer.isBuffer(key)) {
+    return key
+  }
+
+  if (Array.isArray(key)) {
+    return key.map(this._serializeKey, this)
+  }
+
+  if ((typeof key === 'number' || key instanceof Date) && !isNaN(key)) {
+    return key
+  }
+
+  return String(key)
+}
+
 // NOTE: doesn't match abstract signature yet (which has no options argument).
 Level.prototype._serializeValue = function (value, options) {
   // TODO: do we still need to support ArrayBuffer?

From d3687277ba684f12ee4583bc33780de2d44da794 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:03:34 +0200
Subject: [PATCH 11/22] remove options.raw (#65)

---
 index.js | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/index.js b/index.js
index 7d4c15a..9ed5b77 100644
--- a/index.js
+++ b/index.js
@@ -43,14 +43,12 @@ Level.prototype._get = function (key, options, callback) {
       // 'NotFound' error, consistent with LevelDOWN API
       return callback(new Error('NotFound'))
     }
-    // by default return buffers, unless explicitly told not to
-    var asBuffer = true
-    if (options.asBuffer === false) asBuffer = false
-    if (options.raw) asBuffer = false
-    if (asBuffer) {
+
+    if (options.asBuffer) {
       if (value instanceof Uint8Array) value = toBuffer(value)
       else value = Buffer.from(String(value))
     }
+
     return callback(null, value, key)
   }, callback)
 }
@@ -98,12 +96,6 @@ Level.prototype._serializeValue = function (value, options) {
   if (value instanceof ArrayBuffer) return Buffer.from(value)
   if (value == null) return ''
 
-  // TODO: remove
-  if (options.raw) return value
-
-  // TODO: remove
-  if (typeof value !== 'object') return value.toString()
-
   return value
 }
 

From 356b004ed179e2ffd042d3dcbcc9465b2ffd265c Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:04:11 +0200
Subject: [PATCH 12/22] remove calls to _serializeValue

---
 index.js | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/index.js b/index.js
index 9ed5b77..52fb99b 100644
--- a/index.js
+++ b/index.js
@@ -58,8 +58,6 @@ Level.prototype._del = function(id, options, callback) {
 }
 
 Level.prototype._put = function (key, value, options, callback) {
-  // TODO: once we upgrade abstract-leveldown, it will call _serializeValue for us.
-  value = this._serializeValue(value, options)
   this.idb.put(key, value, function() { callback() }, callback)
 }
 
@@ -118,9 +116,6 @@ Level.prototype._batch = function (array, options, callback) {
     currentOp = array[i]
     modified[i] = copiedOp
 
-    // TODO: once we upgrade abstract-leveldown, it will call _serializeValue for us.
-    currentOp.value = this._serializeValue(currentOp.value, options)
-
     for (k in currentOp) {
       if (k === 'type' && currentOp[k] == 'del') {
         copiedOp[k] = 'remove'

From d2f4cb0eff8e1c56c76a4207107804833dfb7818 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:05:12 +0200
Subject: [PATCH 13/22] remove options argument from _serializeValue

---
 index.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 52fb99b..aaada0a 100644
--- a/index.js
+++ b/index.js
@@ -88,8 +88,7 @@ Level.prototype._serializeKey = function (key) {
   return String(key)
 }
 
-// NOTE: doesn't match abstract signature yet (which has no options argument).
-Level.prototype._serializeValue = function (value, options) {
+Level.prototype._serializeValue = function (value) {
   // TODO: do we still need to support ArrayBuffer?
   if (value instanceof ArrayBuffer) return Buffer.from(value)
   if (value == null) return ''

From d103e4349feefb6d43b4c9753c611b14b045a580 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:12:04 +0200
Subject: [PATCH 14/22] fix iterator with limit=0

---
 iterator.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/iterator.js b/iterator.js
index bcd9265..e164fb2 100644
--- a/iterator.js
+++ b/iterator.js
@@ -18,15 +18,21 @@ function Iterator (db, options) {
   AbstractIterator.call(this, db)
 
   this._order = options.reverse ? 'DESC': 'ASC'
-  this._limit = options.limit || -1
+  this._limit = options.limit
   this._count = 0
   this._callback = null
   this._cache = []
   this._completed = false
+  this.transaction = null
 
   this._keyAsBuffer = options.keyAsBuffer
   this._valueAsBuffer = options.valueAsBuffer
 
+  if (this._limit === 0) {
+    this._completed = true
+    return
+  }
+
   var lower = ltgt.lowerBound(options)
   var upper = ltgt.upperBound(options)
 
@@ -97,7 +103,7 @@ Iterator.prototype._next = function (callback) {
   // TODO: can remove this after upgrading abstract-leveldown
   if (!callback) throw new Error('next() requires a callback argument')
 
-  if (this.transaction.error !== null) {
+  if (this.transaction !== null && this.transaction.error !== null) {
     var err = this.transaction.error
 
     setTimeout(function() {

From db364abfd89ab782353013e2fc9e333056a80ef3 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:28:21 +0200
Subject: [PATCH 15/22] temporarily add brfs to fix Level/levelup#578

---
 package.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package.json b/package.json
index f0377ad..50c8d0f 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
   "license": "MIT",
   "devDependencies": {
     "airtap": "0.0.5",
+    "brfs": "~1.6.1",
     "browserify": "~16.2.2",
     "levelup": "~3.0.0",
     "tape": "^4.0.0"

From e3d35d71d4795dafce5e1d938afec00d7f075609 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:29:49 +0200
Subject: [PATCH 16/22] fix native type tests

---
 test/custom-tests.js | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/test/custom-tests.js b/test/custom-tests.js
index e347979..af891d4 100644
--- a/test/custom-tests.js
+++ b/test/custom-tests.js
@@ -21,15 +21,14 @@ module.exports.all = function(leveljs, tape, testCommon) {
     })
   })
 
-  // TODO: this should be supported without raw: true. Which is possible once
-  // we upgrade abstract-leveldown (which only tests strings and Buffers now).
-  tape('store native JS types with raw = true', function(t) {
+  // TODO: merge this and the test below. Test all types.
+  tape('store native JS types', function(t) {
     var level = leveljs(testCommon.location())
     level.open(function(err) {
       t.notOk(err, 'no error')
-      level.put('key', true, { raw: true },  function (err) {
+      level.put('key', true, function (err) {
         t.notOk(err, 'no error')
-        level.get('key', { raw: true }, function(err, value) {
+        level.get('key', { asBuffer: false }, function(err, value) {
           t.notOk(err, 'no error')
           t.ok(typeof value === 'boolean', 'is boolean type')
           t.ok(value, 'is truthy')
@@ -45,9 +44,9 @@ module.exports.all = function(leveljs, tape, testCommon) {
     var level = leveljs(testCommon.location())
     level.open(function(err) {
       t.notOk(err, 'no error')
-      level.put('key', NaN, { raw: true }, function (err) {
+      level.put('key', NaN, function (err) {
         t.notOk(err, 'no error')
-        level.get('key', { raw: true }, function(err, value) {
+        level.get('key', { asBuffer: false }, function(err, value) {
           t.notOk(err, 'no error')
           t.ok(Number.isNaN(value), 'is NaN')
           level.close(t.end.bind(t))

From 5618102a1247207c5c7483bc92d1f14ef2872913 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:33:45 +0200
Subject: [PATCH 17/22] fix destroy tests

---
 test/custom-tests.js | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/test/custom-tests.js b/test/custom-tests.js
index af891d4..8488977 100644
--- a/test/custom-tests.js
+++ b/test/custom-tests.js
@@ -60,20 +60,20 @@ module.exports.all = function(leveljs, tape, testCommon) {
 
   tape('test levelup .destroy w/ string', function(t) {
     var location = testCommon.location()
-    var level = levelup(location, {db: leveljs})
-    level.put('key', 'value', function (err) {
+    var db = levelup(leveljs(location))
+    db.put('key', 'value', function (err) {
       t.notOk(err, 'no error')
-      level.get('key', function (err, value) {
+      db.get('key', { asBuffer: false }, function (err, value) {
         t.notOk(err, 'no error')
         t.equal(value, 'value', 'should have value')
-        level.close(function (err) {
+        db.close(function (err) {
           t.notOk(err, 'no error')
           leveljs.destroy(location, function (err) {
             t.notOk(err, 'no error')
-            var level2 = levelup(location, {db: leveljs})
-            level2.get('key', function (err, value) {
-              t.ok(err, 'key is not there')
-              level2.close(t.end.bind(t))
+            var db2 = levelup(leveljs(location))
+            db2.get('key', { asBuffer: false }, function (err, value) {
+              t.ok(err && err.notFound, 'key is not there')
+              db2.close(t.end.bind(t))
             })
           })
         })
@@ -83,20 +83,20 @@ module.exports.all = function(leveljs, tape, testCommon) {
 
   tape('test levelup .destroy w/ db instance', function(t) {
     var location = testCommon.location()
-    var level = levelup(location, {db: leveljs})
-    level.put('key', 'value', function (err) {
+    var db = levelup(leveljs(location))
+    db.put('key', 'value', function (err) {
       t.notOk(err, 'no error')
-      level.get('key', function (err, value) {
+      db.get('key', { asBuffer: false }, function (err, value) {
         t.notOk(err, 'no error')
         t.equal(value, 'value', 'should have value')
-        level.close(function (err) {
+        db.close(function (err) {
           t.notOk(err, 'no error')
-          leveljs.destroy(level.db, function (err) {
+          leveljs.destroy(db.db, function (err) {
             t.notOk(err, 'no error')
-            var level2 = levelup(location, {db: leveljs})
-            level2.get('key', function (err, value) {
-              t.ok(err, 'key is not there')
-              level2.close(t.end.bind(t))
+            var db2 = levelup(leveljs(location))
+            db2.get('key', { asBuffer: false }, function (err, value) {
+              t.ok(err && err.notFound, 'key is not there')
+              db2.close(t.end.bind(t))
             })
           })
         })

From c7bc3b484f15140cf5f12e81d458617415670fdc Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 14:44:51 +0200
Subject: [PATCH 18/22] fix levelup integration tests

---
 package.json         |  1 +
 test/test-levelup.js | 32 +++++++++++++++-----------------
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/package.json b/package.json
index 50c8d0f..e86ec94 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
     "airtap": "0.0.5",
     "brfs": "~1.6.1",
     "browserify": "~16.2.2",
+    "encoding-down": "~5.0.2",
     "levelup": "~3.0.0",
     "tape": "^4.0.0"
   },
diff --git a/test/test-levelup.js b/test/test-levelup.js
index 9e117e7..6b08230 100644
--- a/test/test-levelup.js
+++ b/test/test-levelup.js
@@ -1,27 +1,25 @@
 /*** Levelup tests
-  Temporary to test integration, can be removed later.
+  NOTE: Temporary integration tests, can be removed later. Remember
+  to also remove the encoding-down devDependency.
 ***/
 var levelup = require('levelup')
+var encoding = require('encoding-down')
 var leveljs = require('../')
 var test = require('tape')
 var testCommon = require('./testCommon')
 
-function identity (v) {
-  return v
-}
-
 test('setup', testCommon.setUp)
 
 test('levelup put', function (t) {
   t.plan(4)
 
-  // TODO: update signature after upgrading levelup
-  var db = levelup(testCommon.location(), { db: leveljs })
+  var down = leveljs(testCommon.location())
+  var db = levelup(down)
 
   db.put('name', 'LevelUP string', function (err) {
     t.ifError(err, 'no put error')
 
-    db.get('name', function (err, value) {
+    db.get('name', { asBuffer: false }, function (err, value) {
       t.ifError(err, 'no get error')
       t.is(value, 'LevelUP string')
 
@@ -33,10 +31,10 @@ test('levelup put', function (t) {
 })
 
 test('binary', function (t) {
-  t.plan(6)
+  t.plan(9)
 
-  // TODO: update signature after upgrading levelup
-  var db = levelup(testCommon.location(), { db: leveljs, valueEncoding: 'binary' })
+  var down = leveljs(testCommon.location())
+  var db = levelup(encoding(down, { valueEncoding: 'binary' }))
   var buf = Buffer.from('00ff', 'hex')
 
   db.put('binary', buf, function (err) {
@@ -44,14 +42,14 @@ test('binary', function (t) {
 
     db.get('binary', function (err, value) {
       t.ifError(err, 'no get error')
+      t.ok(Buffer.isBuffer(value), 'is a buffer')
+      t.same(value, buf)
 
-      // This levelup is really old and its binary decoder does:
-      // `return process.browser ? buffer.toString(type) : buffer`
-      t.notOk(Buffer.isBuffer(value), 'not a buffer')
-
-      db.get('binary', { valueEncoding: { decode: identity } }, function (err, value) {
+      db.get('binary', { valueEncoding: 'id' }, function (err, value) {
         t.ifError(err, 'no get error')
-        t.ok(Buffer.isBuffer(value), 'is a buffer')
+        t.notOk(Buffer.isBuffer(value), 'is not a buffer')
+        t.ok(value instanceof Uint8Array, 'is a Uint8Array')
+        t.same(Buffer.from(value), buf)
 
         db.close(function (err) {
           t.ifError(err, 'no close error')

From f6db11630c579204d2d46199066aeff71d83c58a Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 15:05:56 +0200
Subject: [PATCH 19/22] test buffer keys

---
 test/custom-tests.js | 44 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 3 deletions(-)

diff --git a/test/custom-tests.js b/test/custom-tests.js
index 8488977..64e2fd9 100644
--- a/test/custom-tests.js
+++ b/test/custom-tests.js
@@ -3,9 +3,7 @@ var levelup = require('levelup')
 module.exports.all = function(leveljs, tape, testCommon) {
   tape('setUp', testCommon.setUp)
 
-  // This is covered by abstract-leveldown tests, but we're
-  // not on latest yet, so this is insurance.
-  tape('store buffer value', function(t) {
+  tape('buffer value', function(t) {
     var level = leveljs(testCommon.location())
     level.open(function(err) {
       t.notOk(err, 'no error')
@@ -21,6 +19,46 @@ module.exports.all = function(leveljs, tape, testCommon) {
     })
   })
 
+  // This should be covered by abstract-leveldown tests, but that's
+  // prevented by process.browser checks (Level/abstract-leveldown#121).
+  // This test is adapted from memdown.
+  tape('buffer keys', function (t) {
+    var db = leveljs(testCommon.location())
+
+    db.open(function (err) {
+      t.ifError(err, 'no open error')
+
+      var one = Buffer.from('80', 'hex')
+      var two = Buffer.from('c0', 'hex')
+
+      t.ok(two.toString() === one.toString(), 'would be equal when not buffer-aware')
+      t.ok(Buffer.compare(two, one) > 0, 'but greater when buffer-aware')
+
+      db.put(one, 'one', function (err) {
+        t.notOk(err, 'no error')
+
+        db.get(one, { asBuffer: false }, function (err, value) {
+          t.notOk(err, 'no error')
+          t.equal(value, 'one', 'value one ok')
+
+          db.put(two, 'two', function (err) {
+            t.notOk(err, 'no error')
+
+            db.get(one, { asBuffer: false }, function (err, value) {
+              t.notOk(err, 'no error')
+              t.equal(value, 'one', 'value one is the same')
+
+              db.close(function (err) {
+                t.ifError(err, 'no close error')
+                t.end()
+              })
+            })
+          })
+        })
+      })
+    })
+  })
+
   // TODO: merge this and the test below. Test all types.
   tape('store native JS types', function(t) {
     var level = leveljs(testCommon.location())

From f6009936bb0f8ab2fa0ae0dfbd3162342394995e Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 15:07:03 +0200
Subject: [PATCH 20/22] test that iterator stringifies buffer input

---
 test/custom-tests.js | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/test/custom-tests.js b/test/custom-tests.js
index 64e2fd9..8086045 100644
--- a/test/custom-tests.js
+++ b/test/custom-tests.js
@@ -59,6 +59,31 @@ module.exports.all = function(leveljs, tape, testCommon) {
     })
   })
 
+  // Adapted from a memdown test.
+  tape('iterator stringifies buffer input', function (t) {
+    t.plan(6)
+
+    var db = leveljs(testCommon.location())
+
+    db.open(function (err) {
+      t.ifError(err, 'no open error')
+
+      db.put(1, 2, function (err) {
+        t.ifError(err, 'no put error')
+
+        testCommon.collectEntries(db.iterator(), function (err, entries) {
+          t.ifError(err, 'no iterator error')
+          t.same(entries[0].key, Buffer.from('1'), 'key is stringified')
+          t.same(entries[0].value, Buffer.from('2'), 'value is stringified')
+
+          db.close(function (err) {
+            t.ifError(err, 'no close error')
+          })
+        })
+      })
+    })
+  })
+
   // TODO: merge this and the test below. Test all types.
   tape('store native JS types', function(t) {
     var level = leveljs(testCommon.location())

From c94500d71558dd5affa1816a09f7129f43f2b173 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 16:43:49 +0200
Subject: [PATCH 21/22] detect binary key support (#58)

---
 index.js             | 31 +++++++++++++++++++++----------
 test/custom-tests.js |  4 ++--
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/index.js b/index.js
index aaada0a..29c51d9 100644
--- a/index.js
+++ b/index.js
@@ -17,6 +17,20 @@ function Level(location) {
 
 util.inherits(Level, AbstractLevelDOWN)
 
+// Detect binary key support (IndexedDB Second Edition)
+Level.binaryKeys = (function () {
+  if (typeof indexedDB === 'undefined') {
+    return false
+  }
+
+  try {
+    indexedDB.cmp(new Uint8Array(0), 0)
+    return true
+  } catch (err) {
+    return false
+  }
+})()
+
 Level.prototype._open = function(options, callback) {
   var self = this
 
@@ -71,17 +85,14 @@ Level.prototype._put = function (key, value, options, callback) {
 //   types themselves.
 Level.prototype._serializeKey = function (key) {
   // TODO: do we still need to support ArrayBuffer?
-  if (key instanceof ArrayBuffer) return Buffer.from(key)
-
-  if (typeof key === 'string' || Buffer.isBuffer(key)) {
-    return key
-  }
-
-  if (Array.isArray(key)) {
+  if (key instanceof ArrayBuffer) {
+    key = Buffer.from(key)
+    return Level.binaryKeys ? key : key.toString()
+  } else if (Buffer.isBuffer(key)) {
+    return Level.binaryKeys ? key : key.toString()
+  } else if (Array.isArray(key)) {
     return key.map(this._serializeKey, this)
-  }
-
-  if ((typeof key === 'number' || key instanceof Date) && !isNaN(key)) {
+  } else if ((typeof key === 'number' || key instanceof Date) && !isNaN(key)) {
     return key
   }
 
diff --git a/test/custom-tests.js b/test/custom-tests.js
index 8086045..234b42c 100644
--- a/test/custom-tests.js
+++ b/test/custom-tests.js
@@ -22,7 +22,7 @@ module.exports.all = function(leveljs, tape, testCommon) {
   // This should be covered by abstract-leveldown tests, but that's
   // prevented by process.browser checks (Level/abstract-leveldown#121).
   // This test is adapted from memdown.
-  tape('buffer keys', function (t) {
+  leveljs.binaryKeys && tape('buffer keys', function (t) {
     var db = leveljs(testCommon.location())
 
     db.open(function (err) {
@@ -60,7 +60,7 @@ module.exports.all = function(leveljs, tape, testCommon) {
   })
 
   // Adapted from a memdown test.
-  tape('iterator stringifies buffer input', function (t) {
+  leveljs.binaryKeys && tape('iterator stringifies buffer input', function (t) {
     t.plan(6)
 
     var db = leveljs(testCommon.location())

From 4dd6909698317d436187bcd92c4b6af76038aa59 Mon Sep 17 00:00:00 2001
From: Vincent Weevers <mail@vincentweevers.nl>
Date: Thu, 24 May 2018 18:30:52 +0200
Subject: [PATCH 22/22] remove brfs after levelup fix

---
 package.json | 1 -
 1 file changed, 1 deletion(-)

diff --git a/package.json b/package.json
index e86ec94..bb4b2ec 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,6 @@
   "license": "MIT",
   "devDependencies": {
     "airtap": "0.0.5",
-    "brfs": "~1.6.1",
     "browserify": "~16.2.2",
     "encoding-down": "~5.0.2",
     "levelup": "~3.0.0",