Add a default insights config

This will make the project follow the configuration from the group,
if no project specific configuration was set.

doc/user/group/insights/index.md

@@ -20,6 +20,10 @@ the project that holds your `.gitlab/insights.yml` configuration file:
 
 ![group insights configuration](img/insights_group_configuration.png)
 
+If no configuration was set, a [default configuration file](
+https://gitlab.com/gitlab-org/gitlab-ee/blob/master/ee/fixtures/insights/ee/fixtures/insights/default.yml)
+will be used.
+
 See the [Project's Insights documentation](../../project/insights/index.md) for
 more details about the `.gitlab/insights.yml` configuration file.
 

doc/user/project/insights/index.md

@@ -28,6 +28,11 @@ NOTE: **Note:**
 Once the configuration file is created, you can also
 [use it for your project's group](../../group/insights/index.md#configure-your-insights).
 
+NOTE: **Note:**
+If the project doesn't have any configuration file, it'll try to use
+the group configuration if possible. If the group doesn't have any
+configuration, the default configuration will be used.
+
 ## Permissions
 
 If you have access to view a project, then you have access to view their

ee/app/models/concerns/insights_feature.rb

@@ -4,25 +4,57 @@ module InsightsFeature
   extend ActiveSupport::Concern
   include ::Gitlab::Utils::StrongMemoize
 
+  DEFAULT_INSIGHT_CONFIG = 'ee/fixtures/insights/default.yml'
+
   def insights_available?
     beta_feature_available?(:insights)
   end
 
-  def insights_config
+  def insights_config(follow_group: true)
     case self
     when Group
-      insight&.project&.insights_config
+      # When there's a config file, we use it regardless it's valid or not
+      if insight&.project&.project_insights_config_yaml
+        insight.project.insights_config(follow_group: false)
+      else # When there's nothing, then we use the default
+        default_insights_config
+      end
     when Project
-      return if repository.empty?
-
-      insights_config_yml = repository.insights_config_for(repository.root_ref)
-      return unless insights_config_yml
+      yaml = project_insights_config_yaml
 
-      strong_memoize(:insights_config) do
-        ::Gitlab::Config::Loader::Yaml.new(insights_config_yml).load!
-      rescue Gitlab::Config::Loader::FormatError
-        nil
+      # When there's a config file, we use it regardless it's valid or not
+      if yaml
+        strong_memoize(:insights_config) do
+          ::Gitlab::Config::Loader::Yaml.new(yaml).load!
+        rescue Gitlab::Config::Loader::FormatError
+          nil
+        end
+      # When we're following the group and there's a group then we use it
+      elsif follow_group && group
+        group.insights_config
+      # A project might not have a group, then we just use the default
+      else
+        default_insights_config
       end
     end
   end
+
+  def default_insights_config
+    strong_memoize(:default_insights_config) do
+      yaml = File.read(Rails.root.join(DEFAULT_INSIGHT_CONFIG).to_s)
+      ::Gitlab::Config::Loader::Yaml.new(yaml).load!
+    rescue Gitlab::Config::Loader::FormatError
+      nil
+    end
+  end
+
+  protected
+
+  def project_insights_config_yaml
+    strong_memoize(:project_insights_config_yaml) do
+      next if repository.empty?
+
+      repository.insights_config_for(repository.root_ref)
+    end
+  end
 end

ee/fixtures/insights/default.yml

+weeklyMerged:
+  title: Weekly merged merge requests
+  type: bar
+  query:
+    issuable_type: merge_request
+    issuable_state: merged
+    group_by: week
+
+monthlyMerged:
+  title: Monthly merged merge requests
+  type: bar
+  query:
+    issuable_type: merge_request
+    issuable_state: merged
+    group_by: month
+
+monthlyByPriority:
+  title: Monthly issues by priority
+  type: stacked-bar
+  query:
+    issuable_type: issue
+    collection_labels:
+      - priority::1
+      - priority::2
+      - priority::3
+      - priority::4
+    group_by: month
+
+monthlyBySeverity:
+  title: Monthly issues by severity
+  type: stacked-bar
+  query:
+    issuable_type: issue
+    collection_labels:
+      - severity::1
+      - severity::2
+      - severity::3
+      - severity::4
+    group_by: month

ee/spec/models/group_spec.rb

@@ -403,8 +403,8 @@ describe Group do
 
   describe "#insights_config" do
     context 'when group has no Insights project configured' do
-      it 'returns nil' do
-        expect(group.insights_config).to be_nil
+      it 'returns the default config' do
+        expect(group.insights_config).to eq(group.default_insights_config)
       end
     end
 
@@ -414,8 +414,8 @@ describe Group do
         group.create_insight!(project: project)
       end
 
-      it 'returns nil' do
-        expect(group.insights_config).to be_nil
+      it 'returns the default config' do
+        expect(group.insights_config).to eq(group.default_insights_config)
       end
     end
 

ee/spec/models/project_spec.rb

@@ -1737,8 +1737,48 @@ describe Project do
 
   describe "#insights_config" do
     context 'when project has no Insights config file' do
-      it 'returns nil' do
-        expect(create(:project).insights_config).to be_nil
+      let(:project) { create(:project) }
+
+      it 'returns the project default config' do
+        expect(project.insights_config).to eq(project.default_insights_config)
+      end
+
+      context 'when the project is inside a group' do
+        let(:group) { create(:group) }
+        let(:project) { create(:project, group: group) }
+
+        context 'when the group has no Insights config' do
+          it 'returns the group default config' do
+            expect(project.insights_config).to eq(group.default_insights_config)
+          end
+        end
+
+        context 'when the group has an Insights config from another project' do
+          let(:config_project) do
+            create(:project, :custom_repo, files: { ::Gitlab::Insights::CONFIG_FILE_PATH => insights_file_content })
+          end
+
+          before do
+            group.create_insight!(project: config_project)
+          end
+
+          context 'with a valid config file' do
+            let(:insights_file_content) { 'key: monthlyBugsCreated' }
+
+            it 'returns the group config data from the other project' do
+              expect(project.insights_config).to eq(config_project.insights_config)
+              expect(project.insights_config).to eq(group.insights_config)
+            end
+          end
+
+          context 'with an invalid config file' do
+            let(:insights_file_content) { ': foo bar' }
+
+            it 'returns nil' do
+              expect(project.insights_config).to be_nil
+            end
+          end
+        end
       end
     end
 
@@ -1755,14 +1795,46 @@ describe Project do
 
           expect(insights_config).to eq(key: 'monthlyBugsCreated')
         end
+
+        context 'when the project is inside a group having another config' do
+          let(:config_project) do
+            create(:project, :custom_repo, files: { ::Gitlab::Insights::CONFIG_FILE_PATH => ': foo bar' })
+          end
+
+          before do
+            project.group = create(:group)
+            project.group.create_insight!(project: config_project)
+          end
+
+          it 'returns the project insights config data' do
+            insights_config = project.insights_config
+
+            expect(insights_config).to eq(key: 'monthlyBugsCreated')
+          end
+        end
       end
 
       context 'with an invalid config file' do
         let(:insights_file_content) { ': foo bar' }
 
-        it 'returns the insights config data' do
+        it 'returns nil' do
           expect(project.insights_config).to be_nil
         end
+
+        context 'when the project is inside a group having another config' do
+          let(:config_project) do
+            create(:project, :custom_repo, files: { ::Gitlab::Insights::CONFIG_FILE_PATH => 'key: monthlyBugsCreated' })
+          end
+
+          before do
+            project.group = create(:group)
+            project.group.create_insight!(project: config_project)
+          end
+
+          it 'returns nil' do
+            expect(project.insights_config).to be_nil
+          end
+        end
       end
     end
   end