fix: remove dropBufferSupport option

Author: luin

README.md

@@ -19,20 +19,20 @@ ioredis is a robust, full-featured Redis client that is
 used in the world's biggest online commerce company [Alibaba](http://www.alibaba.com/) and many other awesome companies.
 
 0. Full-featured. It supports [Cluster](http://redis.io/topics/cluster-tutorial), [Sentinel](http://redis.io/topics/sentinel), [Streams](https://redis.io/topics/streams-intro), [Pipelining](http://redis.io/topics/pipelining), and of course [Lua scripting](http://redis.io/commands/eval), [Redis Functions](https://redis.io/topics/functions-intro), [Pub/Sub](http://redis.io/topics/pubsub) (with the support of binary messages).
-0. High performance 🚀.
-0. Delightful API 😄. It works with Node callbacks and Native promises.
-0. Transformation of command arguments and replies.
-0. Transparent key prefixing.
-0. Abstraction for Lua scripting, allowing you to [define custom commands](https://github.com/luin/ioredis#lua-scripting).
-0. Supports [binary data](https://github.com/luin/ioredis#handle-binary-data).
-0. Supports [TLS](https://github.com/luin/ioredis#tls-options) 🔒.
-0. Supports offline queue and ready checking.
-0. Supports ES6 types, such as `Map` and `Set`.
-0. Supports GEO commands 📍.
-0. Supports Redis ACL.
-0. Sophisticated error handling strategy.
-0. Supports NAT mapping.
-0. Supports autopipelining
+1. High performance 🚀.
+2. Delightful API 😄. It works with Node callbacks and Native promises.
+3. Transformation of command arguments and replies.
+4. Transparent key prefixing.
+5. Abstraction for Lua scripting, allowing you to [define custom commands](https://github.com/luin/ioredis#lua-scripting).
+6. Supports [binary data](https://github.com/luin/ioredis#handle-binary-data).
+7. Supports [TLS](https://github.com/luin/ioredis#tls-options) 🔒.
+8. Supports offline queue and ready checking.
+9. Supports ES6 types, such as `Map` and `Set`.
+10. Supports GEO commands 📍.
+11. Supports Redis ACL.
+12. Sophisticated error handling strategy.
+13. Supports NAT mapping.
+14. Supports autopipelining
 
 # Versions
 
@@ -105,35 +105,77 @@ $ npm install ioredis
 
 ```javascript
 const Redis = require("ioredis");
-const redis = new Redis(); // uses defaults unless given configuration object
 
-// ioredis supports all Redis commands:
-redis.set("foo", "bar"); // returns promise which resolves to string, "OK"
+// First, you need to create a Redis instance.
+// We are going to cover how to specify host, port, and other connection
+// options soon.
+const redis = new Redis();
 
-// the format is: redis[SOME_REDIS_COMMAND_IN_LOWERCASE](ARGUMENTS_ARE_JOINED_INTO_COMMAND_STRING)
-// the js: ` redis.set("mykey", "Hello") ` is equivalent to the cli: ` redis> SET mykey "Hello" `
+// Invoke the SET command. This is equivalent to the cli `redis> SET name Bob`:
+redis.set("name", "Bob"); // Returns a Promise
 
-// ioredis supports the node.js callback style
-redis.get("foo", function (err, result) {
+// ioredis provides two kind of APIs, Node.js callback and Promise.
+// 1. You can pass a callback as the last parameter. It will be called when
+//    we get a response from the Redis server:
+redis.get("name", (err, value) => {
   if (err) {
     console.error(err);
   } else {
-    console.log(result); // Promise resolves to "bar"
+    console.log(value); // "Bob"
+  }
+});
+
+// 2. Additionally, every command method returns a Promise
+//    representing the server response:
+redis.get("name").then(
+  (value) => {
+    console.log(value);
+  },
+  (err) => {
+    console.error(err);
   }
+);
+
+// 
+
+// Every
+
+async function main() {
+  await redis.set("mykey", "Hello, World!");
+  const value = await redis.get("mykey"); // value === "Hello, World!"
+}
+
+main();
+```
+
+// ioredis supports all Redis commands:
+redis.set("foo", "bar"); // returns promise which resolves to string, "OK"
+
+// the format is: redis[REDIS_COMMAND_NAME_IN_LOWERCASE](ARGUMENTS_ARE_JOINED_INTO_COMMAND_STRING)
+// the js: `redis.set("mykey", "Hello")` is equivalent to the cli: ` redis> SET mykey "Hello"`
+
+// ioredis supports the Node.js callback style
+redis.get("foo", (err, result) => {
+if (err) {
+console.error(err);
+} else {
+console.log(result); // Promise resolves to "bar"
+}
 });
 
 // Or ioredis returns a promise if the last argument isn't a function
-redis.get("foo").then(function (result) {
-  console.log(result); // Prints "bar"
+redis.get("foo").then((result) => {
+console.log(result); // Prints "bar"
 });
 
 // Most responses are strings, or arrays of strings
 redis.zadd("sortedSet", 1, "one", 2, "dos", 4, "quatro", 3, "three");
-redis.zrange("sortedSet", 0, 2, "WITHSCORES").then((res) => console.log(res)); // Promise resolves to ["one", "1", "dos", "2", "three", "3"] as if the command was ` redis> ZRANGE sortedSet 0 2 WITHSCORES `
+redis.zrange("sortedSet", 0, 2, "WITHSCORES").then((res) => console.log(res)); // Promise resolves to ["one", "1", "dos", "2", "three", "3"] as if the command was `redis> ZRANGE sortedSet 0 2 WITHSCORES`
 
 // All arguments are passed directly to the redis server:
 redis.set("key", 100, "EX", 10);
-```
+
+````
 
 See the `examples/` folder for more examples.
 
@@ -155,7 +197,7 @@ new Redis({
   password: "auth",
   db: 0,
 });
-```
+````
 
 You can also specify connection options as a [`redis://` URL](http://www.iana.org/assignments/uri-schemes/prov/redis) or [`rediss://` URL](https://www.iana.org/assignments/uri-schemes/prov/rediss) when using [TLS encryption](#tls-options):
 

lib/DataHandler.ts

@@ -29,14 +29,13 @@ interface DataHandledable extends EventEmitter {
 
 interface ParserOptions {
   stringNumbers: boolean;
-  dropBufferSupport: boolean;
 }
 
 export default class DataHandler {
   constructor(private redis: DataHandledable, parserOptions: ParserOptions) {
     const parser = new RedisParser({
       stringNumbers: parserOptions.stringNumbers,
-      returnBuffers: !parserOptions.dropBufferSupport,
+      returnBuffers: true,
       returnError: (err: Error) => {
         this.returnError(err);
       },

lib/Pipeline.ts

@@ -245,7 +245,6 @@ Pipeline.prototype.multi = function () {
 
 // @ts-expect-error
 const execBuffer = Pipeline.prototype.execBuffer;
-const exec = Pipeline.prototype.exec;
 // @ts-expect-error
 Pipeline.prototype.execBuffer = deprecate(function () {
   if (this._transactions > 0) {
@@ -278,10 +277,7 @@ Pipeline.prototype.exec = function (callback: Callback): Promise<Array<any>> {
 
   if (this._transactions > 0) {
     this._transactions -= 1;
-    return (this.options.dropBufferSupport ? exec : execBuffer).apply(
-      this,
-      arguments
-    );
+    return execBuffer.apply(this, arguments);
   }
   if (!this.nodeifiedPromise) {
     this.nodeifiedPromise = true;

lib/connectors/SentinelConnector/index.ts

@@ -296,7 +296,6 @@ export default class SentinelConnector extends AbstractConnector {
       enableReadyCheck: false,
       connectTimeout: this.options.connectTimeout,
       commandTimeout: this.options.sentinelCommandTimeout,
-      dropBufferSupport: true,
       ...options,
     });
     // @ts-expect-error

lib/redis/RedisOptions.ts

@@ -15,7 +15,6 @@ interface CommonRedisOptions extends CommanderOptions {
   username?: string;
   password?: string;
   db?: number;
-  dropBufferSupport?: boolean;
   autoResubscribe?: boolean;
   autoResendUnfulfilledCommands?: boolean;
   reconnectOnError?: ReconnectOnError;
@@ -76,7 +75,6 @@ export const DEFAULT_REDIS_OPTIONS: RedisOptions = {
   password: null,
   db: 0,
   // Others
-  dropBufferSupport: false,
   enableOfflineQueue: true,
   enableReadyCheck: true,
   autoResubscribe: true,

lib/redis/event_handler.ts

@@ -72,7 +72,6 @@ export function connectHandler(self) {
     */
     new DataHandler(self, {
       stringNumbers: self.options.stringNumbers,
-      dropBufferSupport: self.options.dropBufferSupport,
     });
 
     if (self.options.enableReadyCheck) {

lib/utils/Commander.ts

@@ -1,5 +1,4 @@
 import { list } from "@ioredis/commands";
-import asCallback from "standard-as-callback";
 import {
   executeWithAutoPipelining,
   shouldUseAutoPipelining,
@@ -14,11 +13,6 @@ export interface CommanderOptions {
   showFriendlyErrorStack?: boolean;
 }
 
-const DROP_BUFFER_SUPPORT_ERROR =
-  "*Buffer methods are not available " +
-  'because "dropBufferSupport" option is enabled.' +
-  "Refer to https://github.com/luin/ioredis/wiki/Improve-Performance for more details.";
-
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 class Commander<Context extends ClientContext = { type: "default" }> {
   options: CommanderOptions = {};
@@ -154,13 +148,6 @@ function generateFunction(
       replyEncoding: _encoding,
     };
 
-    if (this.options.dropBufferSupport && !_encoding) {
-      return asCallback(
-        Promise.reject(new Error(DROP_BUFFER_SUPPORT_ERROR)),
-        callback as Callback | undefined
-      );
-    }
-
     // No auto pipeline, use regular command sending
     if (!shouldUseAutoPipelining(this, functionName, commandName)) {
       return this.sendCommand(
@@ -185,24 +172,18 @@ function generateScriptingFunction(
   functionName: string,
   commandName: string,
   script: Script,
-  encoding: unknown
+  encoding: BufferEncoding | null
 ) {
-  return function (...args) {
+  return function (...args: any[]) {
     const callback =
       typeof args[args.length - 1] === "function" ? args.pop() : undefined;
 
-    let options;
-    if (this.options.dropBufferSupport) {
-      if (!encoding) {
-        return asCallback(
-          Promise.reject(new Error(DROP_BUFFER_SUPPORT_ERROR)),
-          callback
-        );
-      }
-      options = { replyEncoding: null };
-    } else {
-      options = { replyEncoding: encoding };
-    }
+    const options: {
+      replyEncoding: BufferEncoding | null;
+      errorStack?: Error;
+    } = {
+      replyEncoding: encoding,
+    };
 
     if (this.options.showFriendlyErrorStack) {
       options.errorStack = new Error();