update docviewer iwork flag to check region

The docviewer iwork flag only looked at the shipping address before,
this follows the model of what we did with heap, but is contained as a
separate file as the two projects requirements may drift.

closes CAS-1123

test plan:
 - specs pass

Change-Id: Ia9c9a72f7bf000a1dcf352b09751ac0a28713b90
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/307660
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Murilo Paiva <murilo.paiva@instructure.com>
QA-Review: Keith Garner <kgarner@instructure.com>
Product-Review: Keith Garner <kgarner@instructure.com>

lib/feature_flags/docviewer_iwork_predicate.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+#
+# Copyright (C) 2022 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# This was copied from usage_metrics_predicate as the requirements are the same right now. This might not always be
+# true, so this was recreated in a separate file.
+#
+# Right now Apple only has a server in the US, to comply with GDPR, we'll only turn this on for folks in the US.
+module FeatureFlags
+  class DocviewerIworkPredicate
+    def initialize(context, region)
+      @context = context
+      @region = region
+    end
+
+    def call
+      overridden? || (us_billing_code? && in_approved_us_aws_region?)
+    end
+
+    private
+
+    def overridden?
+      @context&.root_account&.settings&.[](:docviewer_enable_iwork_files)
+    end
+
+    def us_billing_code?
+      @context&.root_account&.external_integration_keys&.find_by(key_type: "salesforce_billing_country_code")&.key_value == "US"
+    end
+
+    def in_approved_us_aws_region?
+      ["us-east-1", "us-west-2"].include? @region
+    end
+  end
+end

lib/feature_flags/hooks.rb

@@ -67,10 +67,7 @@ module FeatureFlags
     end
 
     def self.docviewer_enable_iwork_visible_on_hook(context)
-      root_account = context.root_account
-
-      # Right now Apple only has a server in the US, to comply with GDPR, we'll only turn this on for folks in the US.
-      root_account.external_integration_keys.find_by(key_type: "salesforce_billing_country_code")&.key_value == "US"
+      DocviewerIworkPredicate.new(context, Shard.current.database_server.config[:region]).call
     end
 
     def self.usage_metrics_allowed_hook(context)

spec/lib/feature_flags/docviewer_iwork_predicate_spec.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+describe FeatureFlags::DocviewerIworkPredicate do
+  let(:settings) { nil }
+  let(:external_integration_keys) { nil }
+  let(:root_account) { double(settings: settings, external_integration_keys: external_integration_keys) }
+  let(:context) { double(root_account: root_account) }
+  let(:region) { nil }
+  let(:predicate) { FeatureFlags::DocviewerIworkPredicate.new context, region }
+
+  it "defaults to false" do
+    expect(predicate.call).to be_falsey
+  end
+
+  describe "when overridden" do
+    let(:settings) { { docviewer_enable_iwork_files: true } }
+
+    it "returns true" do
+      expect(predicate.call).to be_truthy
+    end
+  end
+
+  describe "when US billing country and approved US aws region" do
+    let(:external_integration_keys) do
+      keys = double
+      allow(keys).to receive(:find_by).with({ key_type: "salesforce_billing_country_code" }) { double(key_value: "US") }
+      keys
+    end
+    let(:region) { "us-east-1" }
+
+    it "returns true" do
+      expect(predicate.call).to be_truthy
+    end
+  end
+end

spec/models/canvadoc_spec.rb

@@ -151,6 +151,8 @@ describe "Canvadoc" do
     before do
       Account.current_domain_root_account = Account.default
       Account.default.external_integration_keys.create!(key_type: "salesforce_billing_country_code", key_value: "US")
+      allow(Shard.current.database_server.config).to receive(:[]).and_call_original
+      allow(Shard.current.database_server.config).to receive(:[]).with(:region).and_return("us-east-1")
     end
 
     after do