Setup simple migration system (#7)

* Setup migrations, misc tidy/fixes

* Simplify migration provider

src/db/index.ts

@@ -1,5 +1,7 @@
-import { Kysely, SqliteDialect } from 'kysely'
 import SqliteDb from 'better-sqlite3'
+import { Kysely, Migrator, SqliteDialect } from 'kysely'
+import { DatabaseSchema } from './schema'
+import { migrationProvider } from './migrations'
 
 export const createDb = (location: string): Database => {
   return new Kysely<DatabaseSchema>({
@@ -9,22 +11,10 @@ export const createDb = (location: string): Database => {
   })
 }
 
+export const migrateToLatest = async (db: Database) => {
+  const migrator = new Migrator({ db, provider: migrationProvider })
+  const { error } = await migrator.migrateToLatest()
+  if (error) throw error
+}
+
 export type Database = Kysely<DatabaseSchema>
-
-export type PostTable = {
-  uri: string
-  cid: string
-  replyParent: string | null
-  replyRoot: string | null
-  indexedAt: string
-}
-
-export type SubStateTable = {
-  service: string
-  cursor: number
-}
-
-export type DatabaseSchema = {
-  posts: PostTable
-  sub_state: SubStateTable
-}

src/db/migrations.ts

@@ -0,0 +1,31 @@
+import { Kysely, Migration, MigrationProvider } from 'kysely'
+
+const migrations: Record<string, Migration> = {}
+
+export const migrationProvider: MigrationProvider = {
+  async getMigrations() {
+    return migrations
+  },
+}
+
+migrations['001'] = {
+  async up(db: Kysely<unknown>) {
+    await db.schema
+      .createTable('post')
+      .addColumn('uri', 'varchar', (col) => col.primaryKey())
+      .addColumn('cid', 'varchar', (col) => col.notNull())
+      .addColumn('replyParent', 'varchar')
+      .addColumn('replyRoot', 'varchar')
+      .addColumn('indexedAt', 'varchar', (col) => col.notNull())
+      .execute()
+    await db.schema
+      .createTable('sub_state')
+      .addColumn('service', 'varchar', (col) => col.primaryKey())
+      .addColumn('cursor', 'integer', (col) => col.notNull())
+      .execute()
+  },
+  async down(db: Kysely<unknown>) {
+    await db.schema.dropTable('post').execute()
+    await db.schema.dropTable('sub_state').execute()
+  },
+}

src/db/schema.ts

@@ -0,0 +1,17 @@
+export type DatabaseSchema = {
+  post: Post
+  sub_state: SubState
+}
+
+export type Post = {
+  uri: string
+  cid: string
+  replyParent: string | null
+  replyRoot: string | null
+  indexedAt: string
+}
+
+export type SubState = {
+  service: string
+  cursor: number
+}

src/feed-generation.ts

@@ -8,7 +8,7 @@ export default function (server: Server, db: Database) {
       throw new InvalidRequestError('algorithm unsupported')
     }
     let builder = db
-      .selectFrom('posts')
+      .selectFrom('post')
       .selectAll()
       .orderBy('indexedAt', 'desc')
       .orderBy('cid', 'desc')
@@ -20,9 +20,9 @@ export default function (server: Server, db: Database) {
       }
       const timeStr = new Date(parseInt(indexedAt, 10)).toISOString()
       builder = builder
-        .where('posts.indexedAt', '<', timeStr)
-        .orWhere((qb) => qb.where('posts.indexedAt', '=', timeStr))
-        .where('posts.cid', '<', cid)
+        .where('post.indexedAt', '<', timeStr)
+        .orWhere((qb) => qb.where('post.indexedAt', '=', timeStr))
+        .where('post.cid', '<', cid)
     }
     const res = await builder.execute()
 

src/index.ts

@@ -9,7 +9,7 @@ const run = async () => {
     subscriptionEndpoint: maybeStr(process.env.FEEDGEN_SUBSCRIPTION_ENDPOINT),
   })
   await server.start()
-  console.log(`🤖 running feed generator at localhost${server.cfg.port}`)
+  console.log(`🤖 running feed generator at localhost:${server.cfg.port}`)
 }
 
 const maybeStr = (val?: string) => {

src/server.ts

@@ -3,7 +3,7 @@ import events from 'events'
 import express from 'express'
 import { createServer } from './lexicon'
 import feedGeneration from './feed-generation'
-import { createDb, Database } from './db'
+import { createDb, Database, migrateToLatest } from './db'
 import { FirehoseSubscription } from './subscription'
 
 export type Config = {
@@ -32,7 +32,7 @@ export class FeedGenerator {
   }
 
   static create(config?: Partial<Config>) {
-    const cfg = {
+    const cfg: Config = {
       port: config?.port ?? 3000,
       sqliteLocation: config?.sqliteLocation ?? 'test.sqlite',
       subscriptionEndpoint: config?.subscriptionEndpoint ?? 'wss://bsky.social',
@@ -56,12 +56,11 @@ export class FeedGenerator {
   }
 
   async start(): Promise<http.Server> {
-    await this.firehose.run()
-    const server = this.app.listen(this.cfg.port)
-    server.keepAliveTimeout = 90000
-    this.server = server
-    await events.once(server, 'listening')
-    return server
+    await migrateToLatest(this.db)
+    this.firehose.run()
+    this.server = this.app.listen(this.cfg.port)
+    await events.once(this.server, 'listening')
+    return this.server
   }
 }
 

src/subscription.ts

@@ -36,13 +36,13 @@ export class FirehoseSubscription extends FirehoseSubscriptionBase {
 
     if (postsToDelete.length > 0) {
       await this.db
-        .deleteFrom('posts')
+        .deleteFrom('post')
         .where('uri', 'in', postsToDelete)
         .execute()
     }
     if (postsToCreate.length > 0) {
       await this.db
-        .insertInto('posts')
+        .insertInto('post')
         .values(postsToCreate)
         .onConflict((oc) => oc.doNothing())
         .execute()

src/util/subscription.ts

@@ -78,7 +78,7 @@ export abstract class FirehoseSubscriptionBase {
 export const getPostOperations = async (evt: Commit): Promise<Operations> => {
   const ops: Operations = { creates: [], deletes: [] }
   const postOps = evt.ops.filter(
-    (op) => op.path.split('/')[1] === ids.AppBskyFeedPost,
+    (op) => op.path.split('/')[0] === ids.AppBskyFeedPost,
   )
 
   if (postOps.length < 1) return ops