fix(cluster): autopipeline when prefix is used

Previously the building of pipelines ignored the key prefix.
It was possible that two keys, foo and bar, might be set into
the same pipeline. However, after being prefixed by a configured
"keyPrefix" value, they may no longer belong to the same
pipeline.

This led to the error:
"All keys in the pipeline should belong to the same slots
allocation group"

Amended version of https://github.com/luin/ioredis/pull/1335/files

This may fix #1264 and #1248.

lib/autoPipelining.ts

@@ -104,7 +104,7 @@ export function executeWithAutoPipelining(
   }
 
   // If we have slot information, we can improve routing by grouping slots served by the same subset of nodes
-  const slotKey = client.isCluster ? client.slots[calculateSlot(args[0])].join(",") : 'main';
+  const slotKey = client.isCluster ? client.slots[calculateSlot(client.options.keyPrefix ? `${client.options.keyPrefix}${args[0]}` : args[0])].join(",") : 'main';
 
   if (!client._autoPipelines.has(slotKey)) {
     const pipeline = client.pipeline();

test/functional/cluster/autopipelining.ts

@@ -35,6 +35,10 @@ describe("autoPipelining for cluster", function () {
       if (argv[0] === "get" && argv[1] === "foo6") {
         return "bar6";
       }
+
+      if (argv[0] === "get" && argv[1] === "baz:foo10") {
+        return "bar10";
+      }
     });
 
     new MockServer(30002, function (argv) {
@@ -68,6 +72,10 @@ describe("autoPipelining for cluster", function () {
         return "bar5";
       }
 
+      if (argv[0] === "get" && argv[1] === "baz:foo1") {
+        return "bar1";
+      }
+
       if (argv[0] === "evalsha") {
         return argv.slice(argv.length - 4);
       }
@@ -177,6 +185,23 @@ describe("autoPipelining for cluster", function () {
     cluster.disconnect();
   });
 
+  it("should support building pipelines when a prefix is used", async () => {
+    const cluster = new Cluster(hosts, {
+      enableAutoPipelining: true,
+      keyPrefix: "baz:",
+    });
+    await new Promise((resolve) => cluster.once("connect", resolve));
+
+    await cluster.set("foo1", "bar1");
+    await cluster.set("foo10", "bar10");
+
+    expect(
+      await Promise.all([cluster.get("foo1"), cluster.get("foo10")])
+    ).to.eql(["bar1", "bar10"]);
+
+    cluster.disconnect();
+  });
+
   it("should support commands queued after a pipeline is already queued for execution", (done) => {
     const cluster = new Cluster(hosts, { enableAutoPipelining: true });