Improve mod stats include_metric matcher

spec/modularization_statistics_spec.rb

@@ -42,36 +42,6 @@ module ModularizationStatistics # rubocop:disable RSpec/DescribedClassModuleWrap
     end
 
     describe 'ModularizationStatistics.get_metrics' do
-      RSpec::Matchers.define(:include_metric) do |expected_metric|
-        match do |actual_metrics|
-          @actual_metrics = actual_metrics
-          @expected_metric = expected_metric
-          @matching_metrics = actual_metrics.select { |actual_metric| actual_metric.name == expected_metric.name }
-          @actual_metric = @matching_metrics.find { |matching_metric| matching_metric.count == expected_metric.count && expected_metric.tags.sort_by(&:key) == matching_metric.tags.sort_by(&:key) }
-          @matching_metrics.any? && !@actual_metric.nil?
-        end
-
-        description do
-          "to have a metric named `#{expected_metric.name}` with count of #{expected_metric.count} and tags of #{expected_metric.tags.map(&:to_s)}"
-        end
-
-        failure_message do
-          if @matching_metrics.none?
-            "Could not find metric with name `#{expected_metric.name}` Could only find metrics with names: #{@actual_metrics.map(&:name)}"
-          else
-            count_diff = "Actual count: #{@matching_metrics.map(&:count)}\nExpected count: #{expected_metric.count}"
-            actual_tags = @matching_metrics.map { |matching_metric| matching_metric.tags.map(&:to_s) }
-            expected_tags = expected_metric.tags.map(&:to_s)
-            tags_diff = "Actual tags (not in expected): #{actual_tags.map { |actual| actual - expected_tags }}\nExpected tags (not in actual): #{expected_tags - actual_tags}"
-            <<~FAILURE_MESSAGE
-              Expected and actual metric `#{expected_metric.name}` are not equal. Found #{@matching_metrics.count} metrics with matching name `#{@expected_metric.name}`, but the properties are different
-              #{count_diff}
-              #{tags_diff}
-            FAILURE_MESSAGE
-          end
-        end
-      end
-
       let(:subject) do
         ModularizationStatistics.get_metrics(
           app_name: 'MyApp',

spec/spec_helper.rb

@@ -55,3 +55,43 @@ def sorbet_double(stubbed_class, attr_map = {})
     allow(CodeOwnership).to receive(:for_file).and_return(sorbet_double(CodeTeams::Team, name: 'Some team'))
   end
 end
+
+RSpec::Matchers.define(:include_metric) do |expected_metric|
+  match do |actual_metrics|
+    @actual_metrics = actual_metrics
+    @expected_metric = expected_metric
+    @metrics_with_same_name = actual_metrics.select { |actual_metric| actual_metric.name == expected_metric.name }
+    @matching_metric = @metrics_with_same_name.find { |matching_metric| matching_metric.count == expected_metric.count && expected_metric.tags.sort_by(&:key) == matching_metric.tags.sort_by(&:key) }
+    @metrics_with_same_name.any? && !@matching_metric.nil?
+  end
+
+  description do
+    "to have a metric named `#{expected_metric.name}` with count of #{expected_metric.count} and tags of #{expected_metric.tags.map(&:to_s)}"
+  end
+
+  failure_message do
+    if @metrics_with_same_name.none?
+      "Could not find metric:\n\n#{expected_metric}\n\nCould only find metrics with names: \n\n#{@actual_metrics.sort_by(&:name).uniq.join("\n")}"
+    else
+
+      # We colorize each part of the output red (if there is no match) or green (if there is a partial match)
+      colorized_metrics = @metrics_with_same_name.sort_by(&:name).map do |actual_metric|
+        count_equal = actual_metric.count == expected_metric.count
+        with_count = "with count #{actual_metric.count}"
+        colorized_with_count = count_equal ? Rainbow(with_count).green : Rainbow(with_count).red
+
+        tags = actual_metric.tags.sort_by(&:key).map do |tag|
+          if expected_metric.tags.include?(tag)
+            Rainbow(tag.to_s).green
+          else
+            Rainbow(tag.to_s).red
+          end
+        end
+
+        "#{Rainbow(actual_metric.name).green} #{colorized_with_count}, with tags #{tags.join(', ')}"
+      end
+
+      "Could not find metric:\n\n#{expected_metric}\n\nCould only find metrics: \n\n#{colorized_metrics.join("\n")}"
+    end
+  end
+end