1 files changed, 142 insertions, 0 deletions
diff --git a/tooling/quality/test_level.rb b/tooling/quality/test_level.rb
new file mode 100644
index 00000000000..ad9de067375
--- /dev/null
+++ b/tooling/quality/test_level.rb
@@ -0,0 +1,142 @@
+# frozen_string_literal: true
+
+module Quality
+  class TestLevel
+    UnknownTestLevelError = Class.new(StandardError)
+
+    TEST_LEVEL_FOLDERS = {
+      migration: %w[
+        migrations
+      ],
+      background_migration: %w[
+        lib/gitlab/background_migration
+        lib/ee/gitlab/background_migration
+      ],
+      frontend_fixture: %w[
+        frontend/fixtures
+      ],
+      unit: %w[
+        bin
+        channels
+        config
+        db
+        dependencies
+        elastic
+        elastic_integration
+        experiments
+        factories
+        finders
+        frontend
+        graphql
+        haml_lint
+        helpers
+        initializers
+        javascripts
+        lib
+        models
+        policies
+        presenters
+        rack_servers
+        replicators
+        routing
+        rubocop
+        serializers
+        services
+        sidekiq
+        spam
+        support_specs
+        tasks
+        uploaders
+        validators
+        views
+        workers
+        tooling
+      ],
+      integration: %w[
+        controllers
+        mailers
+        requests
+      ],
+      system: ['features']
+    }.freeze
+
+    attr_reader :prefix
+
+    def initialize(prefix = nil)
+      @prefix = prefix
+      @patterns = {}
+      @regexps = {}
+    end
+
+    def pattern(level)
+      @patterns[level] ||= "#{prefix}spec/#{folders_pattern(level)}{,/**/}*#{suffix(level)}"
+    end
+
+    def regexp(level)
+      @regexps[level] ||= Regexp.new("#{prefix}spec/#{folders_regex(level)}").freeze
+    end
+
+    def level_for(file_path)
+      case file_path
+      # Detect migration first since some background migration tests are under
+      # spec/lib/gitlab/background_migration and tests under spec/lib are unit by default
+      when regexp(:migration), regexp(:background_migration)
+        :migration
+      # Detect frontend fixture before matching other unit tests
+      when regexp(:frontend_fixture)
+        :frontend_fixture
+      when regexp(:unit)
+        :unit
+      when regexp(:integration)
+        :integration
+      when regexp(:system)
+        :system
+      else
+        raise UnknownTestLevelError, "Test level for #{file_path} couldn't be set. Please rename the file properly or change the test level detection regexes in #{__FILE__}."
+      end
+    end
+
+    def background_migration?(file_path)
+      !!(file_path =~ regexp(:background_migration))
+    end
+
+    private
+
+    def suffix(level)
+      case level
+      when :frontend_fixture
+        ".rb"
+      else
+        "_spec.rb"
+      end
+    end
+
+    def migration_and_background_migration_folders
+      TEST_LEVEL_FOLDERS.fetch(:migration) + TEST_LEVEL_FOLDERS.fetch(:background_migration)
+    end
+
+    def folders_pattern(level)
+      case level
+      when :migration
+        "{#{migration_and_background_migration_folders.join(',')}}"
+      # Geo specs aren't in a specific folder, but they all have the :geo tag, so we must search for them globally
+      when :all, :geo
+        '**'
+      else
+        "{#{TEST_LEVEL_FOLDERS.fetch(level).join(',')}}"
+      end
+    end
+
+    def folders_regex(level)
+      case level
+      when :migration
+        "(#{migration_and_background_migration_folders.join('|')})"
+      # Geo specs aren't in a specific folder, but they all have the :geo tag, so we must search for them globally
+      when :all, :geo
+        ''
+      else
+        "(#{TEST_LEVEL_FOLDERS.fetch(level).join('|')})"
+      end
+    end
+  end
+end