Add generator support for side by side

Generators now support `--side_by_side` as an option to generate the
materialized view update migration with that option set. I also created
an alias so you can use `--side-by-side` as well.

While I was at it, I added `--no-data` as an alias for `--no_data` and
added test coverage for it too.

lib/generators/scenic/materializable.rb

@@ -14,7 +14,14 @@ module Materializable
           type: :boolean,
           required: false,
           desc: "Adds WITH NO DATA when materialized view creates/updates",
-          default: false
+          default: false,
+          aliases: ["--no-data"]
+        class_option :side_by_side,
+          type: :boolean,
+          required: false,
+          desc: "Uses side-by-side strategy to update materialized view",
+          default: false,
+          aliases: ["--side-by-side"]
         class_option :replace,
           type: :boolean,
           required: false,
@@ -35,6 +42,25 @@ def replace_view?
       def no_data?
         options[:no_data]
       end
+
+      def side_by_side?
+        options[:side_by_side]
+      end
+
+      def materialized_view_update_options
+        set_options = { no_data: no_data?, side_by_side: side_by_side? }
+          .select { |_, v| v }
+
+        if set_options.empty?
+          "true"
+        else
+          string_options = set_options.reduce("") do |memo, (key, value)|
+            memo + "#{key}: #{value}, "
+          end
+
+          "{ #{string_options.chomp(", ")} }"
+        end
+      end
     end
   end
 end

lib/generators/scenic/view/templates/db/migrate/update_view.erb

@@ -5,7 +5,7 @@ class <%= migration_class_name %> < <%= activerecord_migration_class %>
     <%= method_name %> <%= formatted_plural_name %>,
       version: <%= version %>,
       revert_to_version: <%= previous_version %>,
-      materialized: <%= no_data? ? "{ no_data: true }" : true %>
+      materialized: <%= materialized_view_update_options %>
   <%- else -%>
     <%= method_name %> <%= formatted_plural_name %>, version: <%= version %>, revert_to_version: <%= previous_version %>
   <%- end -%>

spec/generators/scenic/view/view_generator_spec.rb

@@ -37,6 +37,32 @@
     end
   end
 
+  it "sets the no_data option when updating a materialized view" do
+    with_view_definition("aired_episodes", 1, "hello") do
+      allow(Dir).to receive(:entries).and_return(["aired_episodes_v01.sql"])
+
+      run_generator ["aired_episode", "--materialized", "--no-data"]
+      migration = migration_file(
+        "db/migrate/update_aired_episodes_to_version_2.rb"
+      )
+      expect(migration).to contain "materialized: { no_data: true }"
+      expect(migration).not_to contain "side_by_side"
+    end
+  end
+
+  it "sets the side-by-side option when updating a materialized view" do
+    with_view_definition("aired_episodes", 1, "hello") do
+      allow(Dir).to receive(:entries).and_return(["aired_episodes_v01.sql"])
+
+      run_generator ["aired_episode", "--materialized", "--side-by-side"]
+      migration = migration_file(
+        "db/migrate/update_aired_episodes_to_version_2.rb"
+      )
+      expect(migration).to contain "materialized: { side_by_side: true }"
+      expect(migration).not_to contain "no_data"
+    end
+  end
+
   it "uses 'replace_view' instead of 'update_view' if replace flag is set" do
     with_view_definition("aired_episodes", 1, "hello") do
       allow(Dir).to receive(:entries).and_return(["aired_episodes_v01.sql"])