From 247a81c047264ba638abb9a2ef2ca14801094040 Mon Sep 17 00:00:00 2001
From: Trent Mick <trentm@gmail.com>
Date: Fri, 13 Oct 2023 05:04:30 -0700
Subject: [PATCH] fix(instrumentation-redis-4): avoid shimmer warning by only
 wrapping multi/MULTI if they exist (#1729)

Co-authored-by: Marc Pichler <marc.pichler@dynatrace.com>
---
 .../src/instrumentation.ts                    | 38 +++++++++++--------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/plugins/node/opentelemetry-instrumentation-redis-4/src/instrumentation.ts b/plugins/node/opentelemetry-instrumentation-redis-4/src/instrumentation.ts
index 07628f2055..aa30a98822 100644
--- a/plugins/node/opentelemetry-instrumentation-redis-4/src/instrumentation.ts
+++ b/plugins/node/opentelemetry-instrumentation-redis-4/src/instrumentation.ts
@@ -166,23 +166,31 @@ export class RedisInstrumentation extends InstrumentationBase<any> {
         this._diag.debug('Patching redis client');
         const redisClientPrototype = moduleExports?.default?.prototype;
 
-        if (isWrapped(redisClientPrototype?.multi)) {
-          this._unwrap(redisClientPrototype, 'multi');
+        // In some @redis/client versions 'multi' is a method. In later
+        // versions, as of https://github.com/redis/node-redis/pull/2324,
+        // 'MULTI' is a method and 'multi' is a property defined in the
+        // constructor that points to 'MULTI', and therefore it will not
+        // be defined on the prototype.
+        if (redisClientPrototype?.multi) {
+          if (isWrapped(redisClientPrototype?.multi)) {
+            this._unwrap(redisClientPrototype, 'multi');
+          }
+          this._wrap(
+            redisClientPrototype,
+            'multi',
+            this._getPatchRedisClientMulti()
+          );
         }
-        this._wrap(
-          redisClientPrototype,
-          'multi',
-          this._getPatchRedisClientMulti()
-        );
-
-        if (isWrapped(redisClientPrototype?.MULTI)) {
-          this._unwrap(redisClientPrototype, 'MULTI');
+        if (redisClientPrototype?.MULTI) {
+          if (isWrapped(redisClientPrototype?.MULTI)) {
+            this._unwrap(redisClientPrototype, 'MULTI');
+          }
+          this._wrap(
+            redisClientPrototype,
+            'MULTI',
+            this._getPatchRedisClientMulti()
+          );
         }
-        this._wrap(
-          redisClientPrototype,
-          'MULTI',
-          this._getPatchRedisClientMulti()
-        );
 
         if (isWrapped(redisClientPrototype?.sendCommand)) {
           this._unwrap(redisClientPrototype, 'sendCommand');