Push schema programatically?

[Nikola-Milovic]

Hey! I manage my schema purely in Drizzle and I mostly push the schema during development, and I would like to also push the schema during tests. For that I would need a method like db.migrate({schema: my_schemas}), that does NOT require having pregenerated migration files like the current migration function does.

I am looking through the issues and discussions and cant find any mentions of this feature, is this not a common need for people? How do you migrate your db during tests?

[thekiwi]

I've tried to do the same for the exact same reason. It doesn't appear to be a supported feature but here are a couple of issues that I've come across that helped me in my journey: #2853 and #3913

I'm using Vitest for testing and my current setup.ts looks like this:

import { createRequire } from 'node:module';
import { PGlite } from '@electric-sql/pglite';
import type * as DrizzleKit from 'drizzle-kit/api';
import { drizzle, PgliteDatabase } from 'drizzle-orm/pglite';
import { afterAll, vi } from 'vitest';
import { relations } from '@/db/relations';
import * as schema from '@/db/schema';

// workaround for https://github.com/drizzle-team/drizzle-orm/issues/2853
const require = createRequire(import.meta.url);
const { generateDrizzleJson, generateMigration } = require('drizzle-kit/api') as typeof DrizzleKit;
// end of workaround

// workaround for https://github.com/drizzle-team/drizzle-orm/issues/3913
async function pushSchema(db: PgliteDatabase<typeof schema, typeof relations>) {
  const prevJson = generateDrizzleJson({});
  const curJson = generateDrizzleJson(schema, prevJson.id, undefined, 'snake_case');
  const statements = await generateMigration(prevJson, curJson);
  for (const statement of statements) {
    await db.execute(statement);
  }
}
// end of workaround

let client: PGlite;

// Replace the database with an in-memory database (Pglite)
vi.mock('@/db', async () => {
  client = new PGlite();
  const db = drizzle(client, { schema, relations, casing: 'snake_case' });
  await pushSchema(db);
  return { default: db };
});

afterAll(async () => {
  await client?.close();
});

Hope that helps!

[kravetsone]

Why not just apply current migrations? Because of fast schema changes?

Also maybe reverse engineering of bunx drizzle-kit push would be helpful

[Nikola-Milovic]

For me its mostly the infancy of the project, it keeps evolving, the schema changing, so I don't actually still have a set in stone schema, so while I do generate migrations for test purposes, it can get flaky if I forget to migrate. Also for tests in general, its much faster to push 10 create tables rather than 500 alters and updates from 50 different migrations.

[Strernd]

Would pushSchema from drizzle-kit/api not be the exact function for this purpose?

[Nikola-Milovic]

I couldn't find the docs for it, so I don't actually know how to use it properly

declare const pushSchema: (imports: Record<string, unknown>, drizzleInstance: PgDatabase<any>, schemaFilters?: string[], tablesFilter?: string[], extensionsFilters?: Config["extensionsFilters"]) => Promise<{
    hasDataLoss: boolean;
    warnings: string[];
    statementsToExecute: string[];
    apply: () => Promise<void>;
}>;

[sevspo]

Hello, I would really like to know how to use this function as well. There seems to be very little information about how to apply push and migrations in production.

[wilfredjonathanjames]

I think you'll find what you're looking for here- #4205 (Using in-memory Postgres when testing with vitest)