feat(article-versioning): migrate articles to new drafts

db/migrations/20200925181638_alter_draft_as_article.js

@@ -5,6 +5,7 @@ exports.up = async (knex) => {
   // Draft
   await knex.schema.table(draft_table, (t) => {
     // drop deprecated
+    t.dropColumn('upstream_id')
     t.dropColumn('scheduled_at')
 
     // new from article
@@ -49,5 +50,7 @@ exports.down = async (knex) => {
     t.dropColumn('word_count')
 
     t.timestamp('scheduled_at')
+    t.bigInteger('upstream_id').unsigned()
+    t.foreign('upstream_id').references('id').inTable(article_table)
   })
 }

db/migrations/20200925214015_migrate_article_to_draft.js

@@ -0,0 +1,50 @@
+const chunk = require('lodash/chunk')
+const { v4: uuidv4 } = require('uuid')
+
+const article_table = 'article'
+const draft_table = 'draft'
+
+const CHUNK_SIZE = 10
+
+exports.up = async (knex) => {
+  // Gather articles without `draft_id`
+  const articles = await knex(article_table).select('id')
+  const chunks = chunk(articles, CHUNK_SIZE)
+
+  for (const ids of chunks) {
+    // Gather articles with fields to be migrated
+    const items = await knex(article_table)
+      .select(
+        'id',
+        'draft_id',
+
+        'word_count',
+        'data_hash',
+        'media_hash',
+        'language'
+      )
+      .whereIn(
+        'id',
+        ids.map(({ id }) => id)
+      )
+
+    // Update drafts
+    await Promise.all(
+      items.map(async (item) => {
+        const result = await knex(draft_table)
+          .where({ id: item.draft_id })
+          .update({
+            article_id: item.id,
+            word_count: item.word_count,
+            data_hash: item.data_hash,
+            media_hash: item.media_hash,
+            language: item.language,
+          })
+          .returning('id')
+        console.log(`article (${item.id}) updated to draft (${result[0]})`)
+      })
+    )
+  }
+}
+
+exports.down = async (knex) => {}