Account::Sync model and test fixture simplifications (#968)

* Add sync model

* Fresh fixtures for sync tests

* Sync tests overhaul

* Fix entry tests

* Complete remaining model test updates

* Update system tests

* Update demo data task

* Add system tests back to PR checks

* More simplifications, add empty family to fixtures for easier testing

test/models/account/sync_test.rb

@@ -0,0 +1,36 @@
+require "test_helper"
+
+class Account::SyncTest < ActiveSupport::TestCase
+  setup do
+    @account = accounts(:depository)
+
+    @sync = Account::Sync.for(@account)
+    @balance_syncer = mock("Account::Balance::Syncer")
+    Account::Balance::Syncer.expects(:new).with(@account, start_date: nil).returns(@balance_syncer).once
+  end
+
+  test "runs sync" do
+    @balance_syncer.expects(:run).once
+    @balance_syncer.expects(:warnings).returns([ "test sync warning" ]).once
+
+    assert_equal "pending", @sync.status
+    assert_equal [], @sync.warnings
+    assert_nil @sync.last_ran_at
+
+    @sync.run
+
+    assert_equal "completed", @sync.status
+    assert_equal [ "test sync warning" ], @sync.warnings
+    assert @sync.last_ran_at
+  end
+
+  test "handles sync errors" do
+    @balance_syncer.expects(:run).raises(StandardError.new("test sync error"))
+
+    @sync.run
+
+    assert @sync.last_ran_at
+    assert_equal "failed", @sync.status
+    assert_equal "test sync error", @sync.error
+  end
+end