Add evaluate command

lib/mosaik/commands/evaluate.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+module MOSAIK
+  module Commands
+    ##
+    # Evaluate microservice candidates
+    #
+    class Evaluate < Command
+      self.description = "Evaluate microservice candidates"
+
+      defaults file: "mosaik-candidates.csv"
+
+      argument "--file FILE", "File for the identified microservice candidates graph (default: #{defaults[:file]})"
+
+      def validate
+        raise OptionError, "file not found: #{options[:file]}" unless File.exist? options[:file]
+      end
+
+      def call
+        info "Evaluating microservice candidates (#{options.map { |k, v| "#{k}: #{v}" }.join(', ')})"
+
+        # Evaluate modularity
+        Metrics::Modularity
+          .new(options, graph)
+          .evaluate
+
+        # Print the clusters
+        graph.clusters.each_value do |cluster|
+          info "Cluster #{cluster.id} (modularity: #{cluster.attributes[:modularity]})"
+
+          next unless options[:debug]
+
+          debug "Components: #{cluster.vertices.map(&:id).join(', ')}"
+        end
+
+        file = "#{File.basename(options[:file], '.*')}-evaluation"
+
+        # Write graph to file
+        File.write("#{file}.csv", graph.to_csv)
+
+        info "Dependency graph written to #{options[:file]}"
+
+        return unless options[:visualize]
+
+        # Write visualization to file
+        debug graph.to_dot
+        graph.to_png(file)
+
+        info "Evaluated microservice candidate graph written to #{file}.dot and rendered to #{file}.png"
+      end
+
+      private
+
+      def graph
+        @graph ||= Graph::Graph.from_csv(File.read(options[:file]))
+      end
+    end
+  end
+end

spec/mosaik/commands/evaluate_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+RSpec.describe MOSAIK::Commands::Evaluate do
+  subject(:command) { build(:evaluate_command, arguments:) }
+
+  let(:arguments) { [] }
+
+  describe "#validate" do
+    it "does not raise an error" do
+      FileUtils.touch("mosaik-candidates.csv")
+
+      expect { command.validate }.not_to raise_error
+    end
+
+    describe "--file" do
+      let(:arguments) { ["--file", "doesnotexist.csv"] }
+
+      it "raises an error" do
+        expect { command.validate }.to raise_error MOSAIK::OptionError, "file not found: doesnotexist.csv"
+      end
+    end
+  end
+end

spec/support/factories/commands.rb

@@ -14,6 +14,8 @@
 
   factory :identify_command, parent: :command, class: "MOSAIK::Commands::Identify"
 
+  factory :evaluate_command, parent: :command, class: "MOSAIK::Commands::Evaluate"
+
   factory :init_command, parent: :command, class: "MOSAIK::Commands::Init"
 
   factory :version_command, parent: :command, class: "MOSAIK::Commands::Version"