Add method for_data_warehouse

lib/gitlab/usage/metrics/instrumentations/base_metric.rb

@@ -11,12 +11,12 @@ module Gitlab
           attr_reader :time_frame
           attr_reader :options
 
-          def initialize(time_frame: 'none', options: {})
+          def initialize(time_frame:, options: {})
             @time_frame = time_frame
             @options = options
           end
 
-          def to_sql
+          def for_data_warehouse
             value
           end
         end

lib/gitlab/usage/metrics/instrumentations/database_metric.rb

@@ -59,6 +59,10 @@ module Gitlab
             Gitlab::Usage::Metrics::Query.for(self.class.metric_operation, relation, self.class.column)
           end
 
+          def for_data_warehouse
+            to_sql
+          end
+
           def suggested_name
             Gitlab::Usage::Metrics::NameSuggestion.for(
               self.class.metric_operation,

lib/gitlab/usage/metrics/instrumentations/generic_metric.rb

@@ -28,6 +28,11 @@ module Gitlab
             end
           end
 
+          def initialize(time_frame: 'none', options: {})
+            @time_frame = time_frame
+            @options = options
+          end
+
           def value
             alt_usage_data(fallback: self.class.fallback) do
               self.class.metric_value.call

lib/gitlab/usage_data_non_sql_metrics.rb

@@ -6,7 +6,7 @@ module Gitlab
 
     class << self
       def add_metric(metric)
-        metric.value unless metric.is_a?(Gitlab::Usage::Metrics::Instrumentations::DatabaseMetric)
+        metric.for_data_warehouse
       end
 
       def count(relation, column = nil, batch: true, batch_size: nil, start: nil, finish: nil)

lib/gitlab/usage_data_queries.rb

@@ -6,7 +6,7 @@ module Gitlab
   class UsageDataQueries < UsageData
     class << self
       def add_metric(metric)
-        metric.to_sql
+        metric.for_data_warehouse
       end
 
       def count(relation, column = nil, *args, **kwargs)

spec/lib/gitlab/usage_data_non_sql_metrics_spec.rb

@@ -5,6 +5,14 @@ require 'spec_helper'
 RSpec.describe Gitlab::UsageDataNonSqlMetrics do
   let(:default_count) { Gitlab::UsageDataNonSqlMetrics::SQL_METRIC_DEFAULT }
 
+  describe '#add_metric' do
+    let(:metric) { double(:metric, for_data_warehouse: 1) }
+
+    it 'computes the metric value for given metric' do
+      expect(described_class.add_metric(metric)).to eq(1)
+    end
+  end
+
   describe '.count' do
     it 'returns default value for count' do
       expect(described_class.count(User)).to eq(default_count)

spec/lib/gitlab/usage_data_queries_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe Gitlab::UsageDataQueries do
   end
 
   describe '#add_metric' do
-    let(:metric) { double(:metric, to_sql: 'SELECT COUNT("users"."id") FROM "users"') }
+    let(:metric) { double(:metric, for_data_warehouse: 'SELECT COUNT("users"."id") FROM "users"') }
 
     it 'computes the metric value for given metric' do
       expect(described_class.add_metric(metric)).to eq('SELECT COUNT("users"."id") FROM "users"')