From 3946f3fc5d7e06c0e2c336cb9541566b92a459b9 Mon Sep 17 00:00:00 2001
From: Tom de Bruijn <tom@tomdebruijn.com>
Date: Thu, 11 Apr 2024 13:20:09 +0200
Subject: [PATCH] Check redis-client gem version to prevent error

Version 0.14.0 of the redis-client gem introduced the `@config` object
we rely on in our instrumentation. Add a check using the version number
to make sure we only include our instrumentation on versions that
include this. This will avoid errors from occurring in the
instrumentation itself.

Fixes #1048
---
 .changesets/check-redis-client-version.md     |  6 +++++
 lib/appsignal/hooks/redis_client.rb           |  1 +
 spec/lib/appsignal/hooks/redis_client_spec.rb | 22 ++++++++++++++++---
 3 files changed, 26 insertions(+), 3 deletions(-)
 create mode 100644 .changesets/check-redis-client-version.md

diff --git a/.changesets/check-redis-client-version.md b/.changesets/check-redis-client-version.md
new file mode 100644
index 000000000..baf4e22b0
--- /dev/null
+++ b/.changesets/check-redis-client-version.md
@@ -0,0 +1,6 @@
+---
+bump: "patch"
+type: "fix"
+---
+
+Check the redis-client gem version before installing instrumentation. This prevents errors from being raised on redis-client gem versions older than 0.14.0.
diff --git a/lib/appsignal/hooks/redis_client.rb b/lib/appsignal/hooks/redis_client.rb
index e6c137f4e..2fb5d8520 100644
--- a/lib/appsignal/hooks/redis_client.rb
+++ b/lib/appsignal/hooks/redis_client.rb
@@ -8,6 +8,7 @@ class RedisClientHook < Appsignal::Hooks::Hook
 
       def dependencies_present?
         defined?(::RedisClient) &&
+          Gem::Version.new(::RedisClient::VERSION) >= Gem::Version.new("0.14.0") &&
           Appsignal.config &&
           Appsignal.config[:instrument_redis]
       end
diff --git a/spec/lib/appsignal/hooks/redis_client_spec.rb b/spec/lib/appsignal/hooks/redis_client_spec.rb
index 65147679c..21693a953 100644
--- a/spec/lib/appsignal/hooks/redis_client_spec.rb
+++ b/spec/lib/appsignal/hooks/redis_client_spec.rb
@@ -4,12 +4,28 @@
   end
 
   if DependencyHelper.redis_client_present?
-    context "with redis_client" do
+    context "with redis-client" do
       context "with instrumentation enabled" do
         describe "#dependencies_present?" do
           subject { described_class.new.dependencies_present? }
 
-          it { is_expected.to be_truthy }
+          context "with gem version new than 0.14.0" do
+            before { stub_const("RedisClient::VERSION", "1.2.3") }
+
+            it { is_expected.to be_truthy }
+          end
+
+          context "with gem version 0.14.0" do
+            before { stub_const("RedisClient::VERSION", "0.14.0") }
+
+            it { is_expected.to be_truthy }
+          end
+
+          context "with gem version older than 0.14.0" do
+            before { stub_const("RedisClient::VERSION", "0.13.9") }
+
+            it { is_expected.to be_falsy }
+          end
         end
 
         context "with rest-client gem" do
@@ -211,7 +227,7 @@ def write(_commands)
       end
     end
   else
-    context "without redis" do
+    context "without redis-client" do
       describe "#dependencies_present?" do
         subject { described_class.new.dependencies_present? }