Remove EE::PrometheusAdapter concern

Move validate query spec to CE and drop empty `EE::PrometheusAdapter`

app/models/concerns/prometheus_adapter.rb

@@ -5,8 +5,6 @@ module PrometheusAdapter
 
   included do
     include ReactiveCaching
-    # We can't prepend outside of this model due to the use of `included`, so this must stay here.
-    prepend_if_ee('EE::PrometheusAdapter') # rubocop: disable Cop/InjectEnterpriseEditionModule
 
     self.reactive_cache_lease_timeout = 30.seconds
     self.reactive_cache_refresh_interval = 30.seconds

ee/app/models/concerns/ee/prometheus_adapter.rb

-# frozen_string_literal: true
-
-module EE
-  module PrometheusAdapter
-  end
-end

ee/spec/models/concerns/ee/prometheus_adapter_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-describe EE::PrometheusAdapter, :use_clean_rails_memory_store_caching do
-  include PrometheusHelpers
-  include ReactiveCachingHelpers
-
-  let(:project) { create(:prometheus_project) }
-  let(:service) { project.prometheus_service }
-
-  let(:described_class) do
-    Class.new do
-      include PrometheusAdapter
-    end
-  end
-
-  let(:environment_query) { Gitlab::Prometheus::Queries::EnvironmentQuery }
-
-  describe 'validate_query' do
-    let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
-    let(:validation_query) { Gitlab::Prometheus::Queries::ValidateQuery.name }
-    let(:query) { 'avg(response)' }
-    let(:validation_respone) { { data: { valid: true } } }
-
-    around do |example|
-      Timecop.freeze { example.run }
-    end
-
-    context 'with valid data' do
-      subject { service.query(:validate, query) }
-
-      before do
-        stub_reactive_cache(service, validation_respone, validation_query, query)
-      end
-
-      it 'returns query data' do
-        is_expected.to eq(query: { valid: true })
-      end
-    end
-  end
-end

spec/models/concerns/prometheus_adapter_spec.rb

@@ -18,6 +18,29 @@ describe PrometheusAdapter, :use_clean_rails_memory_store_caching do
   let(:environment_query) { Gitlab::Prometheus::Queries::EnvironmentQuery }
 
   describe '#query' do
+    describe 'validate_query' do
+      let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
+      let(:validation_query) { Gitlab::Prometheus::Queries::ValidateQuery.name }
+      let(:query) { 'avg(response)' }
+      let(:validation_respone) { { data: { valid: true } } }
+
+      around do |example|
+        Timecop.freeze { example.run }
+      end
+
+      context 'with valid data' do
+        subject { service.query(:validate, query) }
+
+        before do
+          stub_reactive_cache(service, validation_respone, validation_query, query)
+        end
+
+        it 'returns query data' do
+          is_expected.to eq(query: { valid: true })
+        end
+      end
+    end
+
     describe 'environment' do
       let(:environment) { build_stubbed(:environment, slug: 'env-slug') }