Breaking: bump abstract-leveldown, encoding-down, levelup

- Removes legacy range options (Level/community#86)
- Drops legacy runtime environments (Level/community#98)
- In browsers, `process.nextTick()` has been replaced with
  `queue-microtask`

UPGRADING.md

@@ -2,7 +2,32 @@
 
 This document describes breaking changes and how to upgrade. For a complete list of changes including minor and patch releases, please refer to the [changelog](CHANGELOG.md).
 
-## v5
+## Upcoming
+
+Legacy range options have been removed ([Level/community#86](https://github.com/Level/community/issues/86)). If you previously did:
+
+```js
+db.createReadStream({ start: 'a', end: 'z' })
+```
+
+An error would now be thrown and you must instead do:
+
+```js
+db.createReadStream({ gte: 'a', lte: 'z' })
+```
+
+The same applies to `db.iterator()`, `db.createKeyStream()` and `db.createValueStream()`.
+
+This release also drops support of legacy runtime environments ([Level/community#98](https://github.com/Level/community/issues/98)):
+
+- Node.js 6 and 8
+- Internet Explorer 11
+- Safari 9-11
+- Stock Android browser (AOSP).
+
+Lastly, in browsers, `process.nextTick()` has been replaced with [`queue-microtask`](https://github.com/feross/queue-microtask), except in streams.
+
+## 5.0.0
 
 ### Fixes iterating buffer keys that contain bytes 196-255 ([#88](https://github.com/level/subleveldown/issues/88))
 
@@ -57,7 +82,7 @@ subdb(db, 'example').on('error', function (err) {
 db.close(function () {})
 ```
 
-## v4
+## 4.0.0
 
 Upgraded to `abstract-leveldown@6`, `encoding-down@6` and `levelup@4`. We recommend to pair `subleveldown@4` with `level` >= 5 or when using a custom store, one that is based on `abstract-leveldown` >= 6. For details please see:
 
@@ -66,7 +91,7 @@ Upgraded to `abstract-leveldown@6`, `encoding-down@6` and `levelup@4`. We recomm
 
 A quick summary: range options are now serialized the same as keys, `db.iterator({ gt: undefined })` is not the same as `db.iterator({})`, nullish values are now rejected and streams are backed by [`readable-stream@3`](https://github.com/nodejs/readable-stream#version-3xx).
 
-## v3
+## 3.0.0
 
 Dropped support for node 4.
 

index.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const subdown = require('./leveldown')
 const levelup = require('levelup')
 const encoding = require('encoding-down')
@@ -6,5 +8,13 @@ module.exports = function (db, prefix, opts) {
   if (typeof prefix === 'object' && !opts) return module.exports(db, null, prefix)
   if (!opts) opts = {}
 
-  return levelup(encoding(subdown(db, prefix, opts), opts), opts)
+  const wrapped = levelup(encoding(subdown(db, prefix, opts), opts), opts)
+
+  // Workaround for abstract-leveldown tests that expect db._nextTick
+  // TODO: fix tests or add _nextTick to levelup for API parity
+  if (!wrapped._nextTick) {
+    wrapped._nextTick = subdown.prototype._nextTick
+  }
+
+  return wrapped
 }

leveldown.js

@@ -1,12 +1,15 @@
+'use strict'
+
 const inherits = require('inherits')
 const abstract = require('abstract-leveldown')
 const wrap = require('level-option-wrap')
 const reachdown = require('reachdown')
 const matchdown = require('./matchdown')
 
-const rangeOptions = 'start end gt gte lt lte'.split(' ')
+const rangeOptions = ['gt', 'gte', 'lt', 'lte']
 const defaultClear = abstract.AbstractLevelDOWN.prototype._clear
 const hasOwnProperty = Object.prototype.hasOwnProperty
+const nextTick = abstract.AbstractLevelDOWN.prototype._nextTick
 
 function concat (prefix, key, force) {
   if (typeof key === 'string' && (force || key.length)) return prefix + key
@@ -228,19 +231,15 @@ function maybeError (leveldown, callback) {
   if (leveldown.status !== 'open') {
     // Same error message as levelup
     // TODO: use require('level-errors').ReadError
-    process.nextTick(callback, new Error('Database is not open'))
+    nextTick(callback, new Error('Database is not open'))
     return true
   }
 
   return false
 }
 
-function fixRange (opts) {
-  return (!opts.reverse || (!opts.end && !opts.start)) ? opts : { start: opts.end, end: opts.start }
-}
-
 SubDown.prototype._iterator = function (opts) {
-  const xopts = addRestOptions(wrap(fixRange(opts), this._wrap), opts)
+  const xopts = addRestOptions(wrap(opts, this._wrap), opts)
   return new SubIterator(this, this.leveldown.iterator(xopts), this.prefix)
 }
 

matchdown.js

@@ -1,3 +1,5 @@
+'use strict'
+
 module.exports = function matchdown (db, type) {
   // Skip layers that we handle ourselves
   if (type === 'levelup') return false

package.json

@@ -16,11 +16,11 @@
     "test": "test"
   },
   "dependencies": {
-    "abstract-leveldown": "^6.3.0",
-    "encoding-down": "^6.2.0",
+    "abstract-leveldown": "^7.1.0",
+    "encoding-down": "^7.0.0",
     "inherits": "^2.0.3",
     "level-option-wrap": "^1.1.0",
-    "levelup": "^4.4.0",
+    "levelup": "^5.0.1",
     "reachdown": "^1.1.0"
   },
   "devDependencies": {
@@ -30,7 +30,7 @@
     "hallmark": "^3.1.0",
     "level-community": "^3.0.0",
     "level-concat-iterator": "^3.0.0",
-    "memdown": "^5.0.0",
+    "memdown": "^6.0.0",
     "nyc": "^14.0.0",
     "standard": "^16.0.3",
     "tape": "^5.0.1"

test/index.js

@@ -13,6 +13,7 @@ const reachdown = require('reachdown')
 const abstract = require('abstract-leveldown')
 const inherits = require('util').inherits
 const EventEmitter = require('events')
+const nextTick = subdown.prototype._nextTick
 
 // Test abstract-leveldown compliance
 function runSuite (factory) {
@@ -179,7 +180,7 @@ test('SubDb main function', function (t) {
 
     const mockdb = mock(abstract.AbstractLevelDOWN, {
       _open: function (opts, cb) {
-        process.nextTick(cb, new Error('error from underlying store'))
+        nextTick(cb, new Error('error from underlying store'))
       }
     })
 
@@ -337,17 +338,17 @@ test('SubDb main function', function (t) {
 
       db.close(function (err) {
         t.ifError(err, 'no close error')
-        t.is(reachdown(sub, 'subleveldown').status, 'opening')
+        t.is(reachdown(sub, 'subleveldown').status, 'new')
         t.is(reachdown(sub).status, 'closed')
-
-        sub.on('error', (err) => {
-          t.is(err.message, 'Parent database is not open')
-          t.is(reachdown(sub, 'subleveldown').status, 'new')
-        })
       })
 
       const sub = subdb(db, 'test')
 
+      sub.on('error', (err) => {
+        t.is(err.message, 'Parent database is not open')
+        t.is(reachdown(sub, 'subleveldown').status, 'new')
+      })
+
       sub.on('open', function () {
         t.fail('should not open')
       })
@@ -486,10 +487,10 @@ test('SubDb main function', function (t) {
       _iterator: function () {
         return {
           next: function (cb) {
-            process.nextTick(cb, new Error('next() error from underlying store'))
+            nextTick(cb, new Error('next() error from underlying store'))
           },
           end: function (cb) {
-            process.nextTick(cb, new Error('end() error from underlying store'))
+            nextTick(cb, new Error('end() error from underlying store'))
           }
         }
       }