fix(db): record superseded migrations after successful upgrades

Author: icecrasher321

packages/db/script-migrations/0016_backfill_search_vectors.postgres.test.ts

@@ -330,10 +330,30 @@ describe.runIf(Boolean(databaseUrl))('search projection upgrade in PostgreSQL',
       FROM generate_series(1, 1001) n`)
     await sql`DELETE FROM embedding_search WHERE id > 'upgrade-0501' AND id LIKE 'upgrade-%'`
     await sql`DELETE FROM embedding_keyword_search WHERE id LIKE 'upgrade-%'`
+    await sql.unsafe(`CREATE FUNCTION cancel_projection_upgrade() RETURNS trigger LANGUAGE plpgsql AS $$
+      BEGIN
+        IF NEW.id = 'upgrade-0750' THEN
+          RAISE EXCEPTION 'Synthetic upgrade cancellation' USING ERRCODE = '57014';
+        END IF;
+        RETURN NEW;
+      END;
+      $$`)
+    await sql.unsafe(`CREATE TRIGGER cancel_projection_upgrade BEFORE INSERT OR UPDATE ON embedding_search
+      FOR EACH ROW EXECUTE FUNCTION cancel_projection_upgrade()`)
+    try {
+      await expect(runScriptMigrations(sql)).rejects.toMatchObject({ code: '57014' })
+      expect(await sql`SELECT name FROM script_migrations WHERE name >= '0015'`).toHaveLength(0)
+    } finally {
+      await sql.unsafe('DROP TRIGGER cancel_projection_upgrade ON embedding_search')
+      await sql.unsafe('DROP FUNCTION cancel_projection_upgrade()')
+    }
     await runScriptMigrations(sql)
     expect(
       await sql`SELECT name FROM script_migrations WHERE name >= '0015' ORDER BY name`
-    ).toEqual([{ name: '0016_backfill_search_vectors' }])
+    ).toEqual([
+      { name: '0015_backfill_embedding_search' },
+      { name: '0016_backfill_search_vectors' },
+    ])
     const [{ complete }] = await sql`SELECT count(*)::int AS complete FROM embedding e
       JOIN embedding_search s ON s.id = e.id JOIN embedding_keyword_search k ON k.id = e.id
       WHERE e.id LIKE 'upgrade-%' AND s."binary" = binary_quantize(e.embedding)::bit(1536)

packages/db/script-migrations/0016_backfill_search_vectors.ts

@@ -231,6 +231,7 @@ export async function buildSearchIndexes(sql: Sql): Promise<void> {
 
 export const backfillSearchVectorsMigration: ScriptMigration = {
   name: '0016_backfill_search_vectors',
+  supersedes: ['0015_backfill_embedding_search'],
   async up(sql) {
     const rows = await backfillSearchVectors(sql)
     const keywordRows = await backfillSearchKeywords(sql)

packages/db/script-migrations/index.ts

@@ -99,10 +99,11 @@ export async function runScriptMigrations(sql: Sql): Promise<void> {
     console.log(`Applying script migration ${migration.name}...`)
     const startedAt = Date.now()
     await migration.up(sql)
-    await sql`
-      INSERT INTO script_migrations (name) VALUES (${migration.name})
-      ON CONFLICT (name) DO NOTHING
-    `
+    await sql.begin(async (tx) => {
+      for (const name of [migration.name, ...(migration.supersedes ?? [])]) {
+        await tx`INSERT INTO script_migrations (name) VALUES (${name}) ON CONFLICT (name) DO NOTHING`
+      }
+    })
     console.log(`Script migration ${migration.name} applied in ${Date.now() - startedAt}ms.`)
   }
 }

packages/db/script-migrations/types.ts

@@ -24,6 +24,8 @@ import type { Sql } from 'postgres'
 export interface ScriptMigration {
   /** Unique stable identifier recorded in `script_migrations`; never rename after release. */
   name: string
+  /** Earlier, unregistered migrations whose work this migration fully completes. Recorded only on success. */
+  supersedes?: readonly string[]
   /** Env vars the migration needs; the runner throws before `up` if any is unset. */
   requiredEnv?: readonly string[]
   /**