Add published_at

app/models/message.rb

@@ -2,6 +2,12 @@
 BLADE_BUCKET_NAME = 'blade.ruby-lang.org'
 
 class Message < ApplicationRecord
+    # Not really sure we will utlize this configuration,
+    # but I don't want to make this column.
+    # https://blade.ruby-lang.org/ruby-talk/1 is JST.
+    # https://blade.ruby-lang.org/ruby-talk/410000 is not.
+    self.skip_time_zone_conversion_for_attributes = [:published_at]
+
     def self.from_s3(list_name, list_seq)
         client = Aws::S3::Client.new(region: BLADE_BUCKET_REGION)
         obj = client.get_object(bucket: BLADE_BUCKET_NAME, key: "#{list_name}/#{list_seq}")
@@ -18,6 +24,13 @@ def self.from_string(str)
           line.split(/:\s+/, 2)
         }.to_h
 
-        self.new(body: body, subject: headers['Subject'], from: headers['From'])
+        published_at = DateTime.strptime(headers['Date'], '%Y-%m-%dT%H:%M:%S%:z')
+
+        self.new(
+            body: body,
+            subject: headers['Subject'],
+            from: headers['From'],
+            published_at: published_at,
+        )
     end
 end

db/migrate/20241010055923_add_published_at_to_messages.rb

@@ -0,0 +1,5 @@
+class AddPublishedAtToMessages < ActiveRecord::Migration[7.1]
+  def change
+    add_column :messages, :published_at, :timestamp
+  end
+end

db/migrate/20241010062050_published_at_time_zone.rb

@@ -0,0 +1,6 @@
+class PublishedAtTimeZone < ActiveRecord::Migration[7.1]
+  # https://github.com/rails/rails/pull/41084
+  def change
+    change_column :messages, :published_at, :timestamptz
+  end
+end

test/models/message_test.rb

@@ -5,11 +5,13 @@ class MessageTest < ActiveSupport::TestCase
     m = Message.from_string(<<END_OF_BODY)
 Subject: [ruby-list:1] Hello
 From: alice@...
-Date: Mon, 01 Jan 2022 12:34:56 +0900
+Date: 2005-12-15T19:32:40+09:00
 
 Hello, world!
 END_OF_BODY
     assert_equal "Hello, world!\n", m.body
     assert_nil m.id
+
+    assert_equal DateTime.parse('2005-12-15T19:32:40+09:00'), m.published_at
   end
 end