Only instrument methods defined directly

When using instrument_methods/instrument_instance_methods we only want
to instrument methods defined directly in a class, not those included
via mixins (e.g. whatever RSpec throws in during development).

In case an externally included method _has_ to be instrumented we can
still use the regular instrument_method/instrument_instance_method
methods.

1 files changed, 26 insertions, 0 deletions

diff --git a/spec/lib/gitlab/metrics/instrumentation_spec.rb b/spec/lib/gitlab/metrics/instrumentation_spec.rb
index fdb0820b875..80dc160ebd2 100644
--- a/spec/lib/gitlab/metrics/instrumentation_spec.rb
+++ b/spec/lib/gitlab/metrics/instrumentation_spec.rb
@@ -119,6 +119,19 @@ describe Gitlab::Metrics::Instrumentation do
 
       expect(@dummy).to respond_to(:_original_foo)
     end
+
+    it 'only instruments methods directly defined in the module' do
+      mod = Module.new do
+        def kittens
+        end
+      end
+
+      @dummy.extend(mod)
+
+      described_class.instrument_methods(@dummy)
+
+      expect(@dummy).to_not respond_to(:_original_kittens)
+    end
   end
 
   describe '.instrument_instance_methods' do
@@ -131,5 +144,18 @@ describe Gitlab::Metrics::Instrumentation do
 
       expect(@dummy.method_defined?(:_original_bar)).to eq(true)
     end
+
+    it 'only instruments methods directly defined in the module' do
+      mod = Module.new do
+        def kittens
+        end
+      end
+
+      @dummy.include(mod)
+
+      described_class.instrument_instance_methods(@dummy)
+
+      expect(@dummy.method_defined?(:_original_kittens)).to eq(false)
+    end
   end
 end