Extract repository

examples/query_based/lib/project_management.rb

@@ -1,4 +1,5 @@
 require_relative "../../../shared/lib/project_management"
 require_relative "project_management/issue"
+require_relative "project_management/repository"
 require_relative "project_management/issue_projection"
 require_relative "project_management/handler"

examples/query_based/lib/project_management/handler.rb

@@ -1,7 +1,7 @@
 module ProjectManagement
   class Handler
     def initialize(event_store)
-      @event_store = event_store
+      @repository = Repository.new(event_store)
     end
 
     def call(cmd)
@@ -65,13 +65,10 @@ def stop(id)
 
     private
 
-    def stream_name(id) = "Issue$#{id}"
-
     def with_aggregate(id)
-      issue =
-        IssueProjection.new(@event_store).call(Issue.initial, stream_name(id))
-
-      @event_store.append(yield(issue), stream_name: stream_name(id))
+      issue = @repository.load(id, Issue.initial)
+      events = yield(issue)
+      @repository.store(id, events)
     end
   end
 end

examples/query_based/lib/project_management/issue_projection.rb

@@ -1,13 +1,7 @@
 module ProjectManagement
   class IssueProjection
-    def initialize(event_store)
-      @event_store = event_store
-    end
-
-    def call(initial_issue, stream_name)
-      @event_store
-        .read
-        .stream(stream_name)
+    def self.call(query, initial_issue)
+      query
         .reduce(initial_issue) do |issue, event|
           case event
           when IssueOpened

examples/query_based/lib/project_management/repository.rb

@@ -0,0 +1,23 @@
+module ProjectManagement
+  class Repository
+    def initialize(event_store)
+      @event_store = event_store
+    end
+
+    def load(id, initial_state)
+      query =
+        @event_store
+        .read
+        .stream(stream_name(id))
+      IssueProjection.call(query, initial_state)
+    end
+
+    def store(id, events)
+      @event_store.append(events, stream_name: stream_name(id))
+    end
+
+    private
+
+    def stream_name(id) = "Issue$#{id}"
+  end
+end