From 567ae381b0b5e6ade455c19264b0433881de20f6 Mon Sep 17 00:00:00 2001
From: Leibale <me@leibale.com>
Date: Tue, 25 Apr 2023 09:48:11 -0400
Subject: [PATCH] "typed" multi

---
 md/v5-new-features.md                       | 17 ++++-------
 packages/client/lib/client/multi-command.ts | 33 ++++++++++++++-------
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/md/v5-new-features.md b/md/v5-new-features.md
index 56dd12b49c..bfac25315b 100644
--- a/md/v5-new-features.md
+++ b/md/v5-new-features.md
@@ -21,20 +21,15 @@ client.withFlags({
 }).hGetAll('key'); // Map<string, Buffer>
 ```
 
-# `Multi.exec<'typed'>`
+# `multi.exec<'typed'>` / `multi.execTyped`
 
-We have introduced the ability to perform a 'typed' `MULTI`/`EXEC` transaction.  Rather than returning `Array<ReplyUnion>`, a transaction invoked with `.exec<'typed'>` will return types appropriate to the commands in the transaction where possible.  
-
-Example:
+We have introduced the ability to perform a "typed" `MULTI`/`EXEC` transaction. Rather than returning `Array<ReplyUnion>`, a transaction invoked with `.exec<'typed'>` will return types appropriate to the commands in the transaction where possible:
 
 ```javascript
-client.multi()
-  .ping()
-  .exec(); // Array<ReplyUnion>
-
-client.multi()
-  .ping()
-  .exec<'typed'>(); // [string]
+const multi = client.multi().ping();
+await multi.exec(); // Array<ReplyUnion>
+await multi.exec<'typed'>(); // [string]
+await multi.execTyped(); // [string]
 ```
 
 # Request & Reply Policies
diff --git a/packages/client/lib/client/multi-command.ts b/packages/client/lib/client/multi-command.ts
index b52190c10a..3503a34af2 100644
--- a/packages/client/lib/client/multi-command.ts
+++ b/packages/client/lib/client/multi-command.ts
@@ -83,10 +83,14 @@ export type RedisClientMultiCommandType<
   WithScripts<REPLIES, M, F, S, RESP, FLAGS>
 );
 
-type ReplyType<
-  REPLIES,
-  T = 'generic'
-> = T extends 'typed' ? REPLIES : Array<ReplyUnion>;
+type MULTI_REPLY = {
+  GENERIC: 'generic';
+  TYPED: 'typed';
+};
+
+type MultiReply = MULTI_REPLY[keyof MULTI_REPLY];
+
+type ReplyType<T extends MultiReply, REPLIES> = T extends MULTI_REPLY['TYPED'] ? REPLIES : Array<ReplyUnion>;
 
 export type RedisClientMultiExecutor = (
   queue: Array<RedisMultiQueuedCommand>,
@@ -144,8 +148,7 @@ export default class RedisClientMultiCommand<REPLIES = []> extends RedisMultiCom
     M extends RedisModules = Record<string, never>,
     F extends RedisFunctions = Record<string, never>,
     S extends RedisScripts = Record<string, never>,
-    RESP extends RespVersions = 2,
-    FLAGS extends Flags = {}
+    RESP extends RespVersions = 2
   >(config?: CommanderConfig<M, F, S, RESP>) {
     return attachConfig({
       BaseClass: RedisClientMultiCommand,
@@ -221,7 +224,7 @@ export default class RedisClientMultiCommand<REPLIES = []> extends RedisMultiCom
 
   select = this.SELECT;
 
-  async exec<T>(execAsPipeline = false) {
+  async exec<T extends MultiReply = MULTI_REPLY['GENERIC']>(execAsPipeline = false) {
     if (execAsPipeline) return this.execAsPipeline<T>();
 
     return this.handleExecReplies(
@@ -230,19 +233,27 @@ export default class RedisClientMultiCommand<REPLIES = []> extends RedisMultiCom
         this.#selectedDB,
         RedisMultiCommand.generateChainId()
       )
-    ) as ReplyType<REPLIES, T>;
+    ) as ReplyType<T, REPLIES>;
   }
 
   EXEC = this.exec;
 
-  async execAsPipeline<T>() {
-    if (this.queue.length === 0) return [] as ReplyType<REPLIES, T>;
+  execTyped(execAsPipeline = false) {
+    return this.exec<MULTI_REPLY['TYPED']>(execAsPipeline);
+  }
+
+  async execAsPipeline<T extends MultiReply = MULTI_REPLY['GENERIC']>() {
+    if (this.queue.length === 0) return [] as ReplyType<T, REPLIES>;
 
     return this.transformReplies(
       await this.#executor(
         this.queue,
         this.#selectedDB
       )
-    ) as ReplyType<REPLIES, T>;
+    ) as ReplyType<T, REPLIES>;
+  }
+
+  execAsPipelineTyped() {
+    return this.execAsPipeline<MULTI_REPLY['TYPED']>();
   }
 }