Add specs for UsageMetricDefinitionGenerator and refactor

spec/lib/generators/gitlab/usage_metric_definition_generator_spec.rb

@@ -3,10 +3,26 @@
 require 'generator_helper'
 
 RSpec.describe Gitlab::UsageMetricDefinitionGenerator do
+  let(:key_path) { 'counts_weekly.test_metric' }
+  let(:dir) { '7d' }
+  let(:temp_dir) { Dir.mktmpdir }
+
+  before do
+    stub_const("#{described_class}::TOP_LEVEL_DIR", temp_dir)
+  end
+
+  describe 'Creating metric definition file' do
+    it 'creates a metric definition file with correct key_path' do
+      described_class.new([key_path], { 'dir' => dir }).invoke_all
+
+      metric_definition_path = Dir.glob(File.join(temp_dir, 'metrics/counts_7d/*_test_metric.yml')).first
+
+      expect(YAML.safe_load(File.read(metric_definition_path))).to include("key_path" => key_path)
+    end
+  end
+
   describe 'Validation' do
-    let(:key_path) { 'counter.category.event' }
-    let(:dir) { '7d' }
-    let(:options) { [key_path, '--dir', dir, '--pretend'] }
+    let(:options) { [key_path, '--dir', dir] }
 
     subject { described_class.start(options) }
 
@@ -42,18 +58,12 @@ RSpec.describe Gitlab::UsageMetricDefinitionGenerator do
   end
 
   describe 'Name suggestions' do
-    let(:temp_dir) { Dir.mktmpdir }
-
-    before do
-      stub_const("#{described_class}::TOP_LEVEL_DIR", temp_dir)
-    end
-
     context 'with product_intelligence_metrics_names_suggestions feature ON' do
       it 'adds name key to metric definition' do
         stub_feature_flags(product_intelligence_metrics_names_suggestions: true)
 
         expect(::Gitlab::Usage::Metrics::NamesSuggestions::Generator).to receive(:generate).and_return('some name')
-        described_class.new(['counts_weekly.test_metric'], { 'dir' => '7d' }).invoke_all
+        described_class.new([key_path], { 'dir' => dir }).invoke_all
         metric_definition_path = Dir.glob(File.join(temp_dir, 'metrics/counts_7d/*_test_metric.yml')).first
 
         expect(YAML.safe_load(File.read(metric_definition_path))).to include("name" => "some name")
@@ -65,7 +75,7 @@ RSpec.describe Gitlab::UsageMetricDefinitionGenerator do
         stub_feature_flags(product_intelligence_metrics_names_suggestions: false)
 
         expect(::Gitlab::Usage::Metrics::NamesSuggestions::Generator).not_to receive(:generate)
-        described_class.new(['counts_weekly.test_metric'], { 'dir' => '7d' }).invoke_all
+        described_class.new([key_path], { 'dir' => dir }).invoke_all
         metric_definition_path = Dir.glob(File.join(temp_dir, 'metrics/counts_7d/*_test_metric.yml')).first
 
         expect(YAML.safe_load(File.read(metric_definition_path)).keys).not_to include(:name)