Add way to run a single group

app/services/rakes/run_matchmaking.rb

@@ -1,16 +1,18 @@
 module Rakes
   class RunMatchmaking
-    def initialize(stdout:, stderr:)
+    def initialize(stdout:, stderr:, only: nil)
       @stdout = stdout
       @stderr = stderr
 
+      @only = only || []
+
       @identifies_nearest_date = IdentifiesNearestDate.new
       @collect_groups = CollectGroups.new
       @establish_matches_for_group = Matchmaking::EstablishMatchesForGroup.new
     end
 
     def call
-      @collect_groups.call.each do |group|
+      groups.each do |group|
         next unless should_run_today?(group.schedule)
 
         unless group.active?
@@ -29,6 +31,10 @@ def call
 
     private
 
+    def groups
+      @collect_groups.call.select { |group| @only.any? ? @only.include?(group.name) : true }
+    end
+
     def should_run_today?(schedule)
       @identifies_nearest_date.call(schedule).today?
     end

lib/tasks/matchmaking.rake

@@ -0,0 +1,19 @@
+namespace :matchmaking do
+  desc "Run matchmaking tasks"
+  task run: :environment do
+    [
+      Rakes::RunMatchmaking.new(stdout: $stdout, stderr: $stdout),
+      Rakes::SendPendingNotifications.new(stdout: $stdout, stderr: $stdout),
+      Rakes::RemovesOldMatches.new
+    ].each(&:call)
+  end
+
+  desc "Run single matchmaking task"
+  task :run_single, [:group_name] => :environment do |_task, args|
+    [
+      Rakes::RunMatchmaking.new(stdout: $stdout, stderr: $stdout, only: [args[:group_name]]),
+      Rakes::SendPendingNotifications.new(stdout: $stdout, stderr: $stdout),
+      Rakes::RemovesOldMatches.new
+    ].each(&:call)
+  end
+end

lib/tasks/scheduler.rake

@@ -1,7 +1,3 @@
 task create_groups: :environment do
-  [
-    Rakes::RunMatchmaking.new(stdout: $stdout, stderr: $stdout),
-    Rakes::SendPendingNotifications.new(stdout: $stdout, stderr: $stdout),
-    Rakes::RemovesOldMatches.new
-  ].each(&:call)
+  Rake::Task["matchmaking:run"].invoke
 end

test/services/rakes/run_matchmaking_test.rb

@@ -81,5 +81,26 @@ class RunMatchmakingTest < ActiveSupport::TestCase
       assert_no_match(/Starting matchmaking for 'test'/, output)
       assert_match(/Matchmaking successfully completed/, output)
     end
+
+    test "only runs specified groups" do
+      groups = [
+        group_with(name: "test1", slack_channel_name: "group-test1", target_size: 2, schedule: :daily),
+        group_with(name: "test2", slack_channel_name: "group-test2", target_size: 3, schedule: :daily),
+        group_with(name: "test3", slack_channel_name: "group-test3", target_size: 4, schedule: :daily)
+      ]
+
+      stubs { @collect_groups.call }.with { groups }
+      stubs(times: 2) { @identifies_nearest_date.call("daily") }.with { @jan_5 }
+      stubs(times: 2) { |m| @establish_matches_for_group.call(m.is_a?(MatchmakingGroup)) }
+
+      @subject.new(stdout: stdout, stderr: stderr, only: ["test1", "test3"]).call
+
+      output = read_output!
+      assert_match(/Starting matchmaking for 'test1'/, output)
+      assert_no_match(/Starting matchmaking for 'test2'/, output)
+      assert_match(/Starting matchmaking for 'test3'/, output)
+      assert_match(/Matchmaking successfully completed/, output)
+      assert_empty read_errors!
+    end
   end
 end