Replace duplexify and friends with readable-stream v4 (#7)

Co-authored-by: Robert Nagy <ronagy@icloud.com>

guest.js

@@ -1,11 +1,10 @@
 'use strict'
 
-const duplexify = require('duplexify')
 const { AbstractLevel, AbstractIterator } = require('abstract-level')
-const eos = require('end-of-stream')
-const lpstream = require('length-prefixed-stream')
+const lpstream = require('@vweevers/length-prefixed-stream')
 const ModuleError = require('module-error')
 const { input, output } = require('./tags')
+const { Duplex, pipeline, finished } = require('readable-stream')
 
 const kExplicitClose = Symbol('explicitClose')
 const kAbortRequests = Symbol('abortRequests')
@@ -108,10 +107,8 @@ class ManyLevelGuest extends AbstractLevel {
       self[kFlushed]()
     })
 
-    const proxy = duplexify()
-    proxy.setWritable(decode)
-    proxy.setReadable(encode)
-    eos(proxy, cleanup)
+    const proxy = Duplex.from({ writable: decode, readable: encode })
+    finished(proxy, cleanup)
     this[kRpcStream] = proxy
     return proxy
 
@@ -312,7 +309,7 @@ class ManyLevelGuest extends AbstractLevel {
     this[kAbortRequests]('Aborted on database close()', 'LEVEL_DATABASE_NOT_OPEN')
 
     if (this[kRpcStream]) {
-      eos(this[kRpcStream], () => {
+      finished(this[kRpcStream], () => {
         this[kRpcStream] = null
         this._close(cb)
       })
@@ -330,7 +327,12 @@ class ManyLevelGuest extends AbstractLevel {
       // For tests only so does not need error handling
       this[kExplicitClose] = false
       const remote = this[kRemote]()
-      remote.pipe(this.connect()).pipe(remote)
+      pipeline(
+        remote,
+        this.connect(),
+        remote,
+        () => {}
+      )
     } else if (this[kExplicitClose]) {
       throw new ModuleError('Cannot reopen many-level database after close()', {
         code: 'LEVEL_NOT_SUPPORTED'

host.js

@@ -1,9 +1,8 @@
 'use strict'
 
-const lpstream = require('length-prefixed-stream')
+const lpstream = require('@vweevers/length-prefixed-stream')
 const ModuleError = require('module-error')
-const eos = require('end-of-stream')
-const duplexify = require('duplexify')
+const { Duplex, finished } = require('readable-stream')
 const { input, output } = require('./tags')
 
 const rangeOptions = new Set(['gt', 'gte', 'lt', 'lte'])
@@ -60,7 +59,7 @@ function createRpcStream (db, options, streamOptions) {
   const readonly = options.readonly
   const decode = lpstream.decode()
   const encode = lpstream.encode()
-  const stream = duplexify(decode, encode)
+  const stream = Duplex.from({ writable: decode, readable: encode })
 
   const preput = options.preput
   const predel = options.predel
@@ -85,7 +84,7 @@ function createRpcStream (db, options, streamOptions) {
 
     const iterators = new Map()
 
-    eos(stream, function () {
+    finished(stream, function () {
       for (const iterator of iterators.values()) {
         iterator.close()
       }

package.json

@@ -25,12 +25,11 @@
     "UPGRADING.md"
   ],
   "dependencies": {
+    "@vweevers/length-prefixed-stream": "^1.0.0",
     "abstract-level": "^1.0.3",
-    "duplexify": "^4.1.1",
-    "end-of-stream": "^1.1.0",
-    "length-prefixed-stream": "^2.0.0",
     "module-error": "^1.0.2",
-    "protocol-buffers-encodings": "^1.1.0"
+    "protocol-buffers-encodings": "^1.1.0",
+    "readable-stream": "^4.0.0"
   },
   "devDependencies": {
     "@types/readable-stream": "^2.3.13",
@@ -43,7 +42,6 @@
     "memory-level": "^1.0.0",
     "nyc": "^15.1.0",
     "protocol-buffers": "^5.0.0",
-    "readable-stream": "^3.6.0",
     "standard": "^16.0.3",
     "tape": "^5.0.1",
     "ts-standard": "^11.0.0",