Extract repository

Author: mostlyobvious

examples/extracted_state/lib/project_management.rb

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

examples/extracted_state/lib/project_management/handler.rb

@@ -1,6 +1,8 @@
 module ProjectManagement
   class Handler
-    def initialize(event_store) = @event_store = event_store
+    def initialize(event_store)
+      @repository = Repository.new(event_store)
+    end
 
     def call(cmd)
       case cmd
@@ -30,18 +32,12 @@ def stop(id) = with_aggregate(id) { |issue| issue.stop }
 
     private
 
-    def stream_name(id) = "Issue$#{id}"
-
     def with_aggregate(id)
-      state =
-        @event_store
-          .read
-          .stream(stream_name(id))
-          .reduce(IssueState.initial(id)) { |state, event| state.apply(event) }
-
-      yield issue = Issue.new(state)
+      state = @repository.load(id, IssueState.initial(id))
+      issue = Issue.new(state)
+      yield issue
 
-      @event_store.append(issue.changes, stream_name: stream_name(id))
+      @repository.store(id, issue.changes)
     end
   end
 end

examples/extracted_state/lib/project_management/repository.rb

@@ -0,0 +1,22 @@
+module ProjectManagement
+  class Repository
+    def initialize(event_store)
+      @event_store = event_store
+    end
+
+    def load(id, initial_state)
+      @event_store
+        .read
+        .stream(stream_name(id))
+        .reduce(initial_state) { |state, event| state.apply(event) }
+    end
+
+    def store(id, events)
+      @event_store.append(events, stream_name: stream_name(id))
+    end
+
+    private
+
+    def stream_name(id) = "Issue$#{id}"
+  end
+end